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Siemens simatic S7-1200. Manual (2015) - page 6

Motion control is easy

10.6 Operation of motion control for S7-1200

Table 10- 24 Configuration parameters for homing the axis

Parameter

Description

Input reference point switch

Select the digital input for the reference point switch from the drop-down list box. The

input must be interrupt-capable. The onboard CPU inputs and inputs of an inserted

(Active and passive homing)

signal board can be selected as inputs for the reference point switch.

The default filter time for the digital inputs is 6.4 ms. When the digital inputs are used

as a reference point switch, this can result in undesired decelerations and thus inac-

curacies. Depending on the reduced velocity and extent of the reference point switch,

the reference point may not be detected. The filter time can be set under "Input filter"

in the device configuration of the digital inputs.

The specified filter time must be less than the duration of the input signal at the refer-

ence point switch.

Auto reverse after reaching the

Activate the check box to use the hardware limit switch as a reversing cam for the

hardware limit switches

reference point approach. The hardware limit switches must be configured and acti-

vated for direction reversal.

(Active homing only)

If the hardware limit switch is reached during active homing, the axis brakes at the

configured deceleration (not with the emergency deceleration) and reverses direction.

The reference point switch is then sensed in reverse direction.

If the direction reversal is not active and the axis reaches the hardware limit switch

during active homing, the reference point approach is aborted with an error and the

axis is braked at the emergency deceleration.

Approach direction

With the direction selection, you determine the "approach direction" used during ac-

tive homing to search for the reference point switch, as well as the homing direction.

(Active and passive homing)

The homing direction specifies the travel direction the axis uses to approach the

configured side of the reference point switch to carry out the homing operation.

Reference point switch

• Active homing: Select whether the axis is to be referenced on the left or right side

(Active and passive homing)

of the reference point switch. Depending on the start position of the axis and the

configuration of the homing parameters, the reference point approach sequence

can differ from the diagram in the configuration window.

• Passive homing: With passive homing, the traversing motions for purposes of

homing must be implemented by the user via motion commands. The side of the

reference point switch on which homing occurs depends on the following factors:

- "Approach direction" configuration

- "Reference point switch" configuration

- Current travel direction during passive homing

Approach velocity

Specify the velocity at which the reference point switch is to be searched for during

the reference point approach.

(Active homing only)

Limit values (independent of the selected user unit):

Start/stop velocity ≤ approach velocity ≤ maximum velocity

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10.6 Operation of motion control for S7-1200

Parameter

Description

Reduced velocity

Specify the velocity at which the axis approaches the reference point switch for hom-

ing.

(Active homing only)

Limit values (independent of the selected user unit):

Start/stop velocity ≤ reduced velocity ≤ maximum velocity

Home position offset

If the desired reference position deviates from the position of the reference point

switch, the home position offset can be specified in this field.

(Active homing only)

If the value does not equal 0, the axis executes the following actions following hom-

ing at the reference point switch:

1. Move the axis at reduced velocity by the value of the home position offset.

2. When the position of the home position offset is reached, the axis position is set

to the absolute reference position. The absolute reference position is specified via

parameter "Position" of motion control instruction "MC_Home".

Limit values (independent of the selected user unit):

-1.0e12 ≤ home position offset ≤ 1.0e12

Table 10- 25 Factors that affect homing

Influencing factors:

Result:

Configuration

Configuration

Current travel direction

Homing on

Approach direction

Reference point switch

Reference point switch

Positive

"Left (negative) side"

Positive direction

Left

Negative direction

Right

Positive

"Right (positive) side"

Positive direction

Right

Negative direction

Left

Negative

"Left (negative) side"

Positive direction

Right

Negative direction

Left

Negative

"Right (positive) side"

Positive direction

Left

Negative direction

Right

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10.6 Operation of motion control for S7-1200

10.6.3.3

Sequence for active homing

You start active homing with motion control instruction "MC_Home" (input parameter

Mode = 3). Input parameter "Position" specifies the absolute reference point coordinates in

this case. Alternatively, you can start active homing on the control panel for test purposes.

The following diagram shows an example of a characteristic curve for an active reference

point approach with the following configuration parameters:

● "Approach direction" = "Positive approach direction"

● "Reference point switch" = "Right (positive) side"

● Value of "home position offset" > 0

Table 10- 26 Velocity characteristics of MC homing

Operation

Notes

A

Approach velocity

B

Reduced velocity

C

Home position coordinate

D

Home position offset

Search phase (blue curve segment): When active homing starts, the axis accelerates to the configured "approach

①

velocity" and searches at this velocity for the reference point switch.

②

Reference point approach (red curve section): When the reference point switch is detected, the axis in this example

brakes and reverses, to be homed on the configured side of the reference point switch at the configured "reduced

velocity".

Travel to reference point position (green curve segment): After homing at the reference point switch, the axis travels

③

to the "Reference point coordinates" at the "reduced velocity". On reaching the "Reference point coordinates", the

axis is stopped at the position value that was specified in the Position input parameter of the MC_Home instruction".

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10.7 Motion control instructions

CPU firmware levels

If you have an S7-1200 CPU with V4.1 firmware, select the V5.0 version of each motion

instruction.

If you have an S7-1200 CPU with V4.0 or earlier firmware, select the applicable V4.0, V3.0,

V2.0, or V1.0 version of each motion instruction.

10.7.2

MC_Power (Release/block axis) instruction

Note

If the axis is switched off due to an error, it will be enabled again automatically after the error

has been eliminated and acknowledged. This requires that the Enable input parameter has

retained the value TRUE during this process.

Table 10- 27 MC_Power instruction

LAD / FBD

SCL

Description

"MC_Power_DB"(

The MC_Power motion control instruction enables

Axis:=_multi_fb_in_,

or disables an axis. Before you can enable or disa-

Enable:=_bool_in_,

ble the axis, ensure the following conditions:

StopMode:=_int_in_,

• The technology object has been configured

Status=>_bool_out_,

correctly.

Busy=>_bool_out_,

• There is no pending enable-inhibiting error.

Error=>_bool_out_,

The execution of MC_Power cannot be aborted by

ErrorID=>_word_out_,

a motion control task. Disabling the axis (input

ErrorIn-

parameter Enable = FALSE) aborts all motion con-

fo=>_word_out_);

trol tasks for the associated technology object.

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_Power_DB" is the name of the instance DB.

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10.7 Motion control instructions

Table 10- 28 Parameters for the MC_Power instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Enable

IN

Bool

• FALSE (default): All active tasks are aborted according to the pa-

rameterized "StopMode" and the axis is stopped.

• TRUE: Motion Control attempts to enable the axis.

StopMode

IN

Int

•

0: Emergency stop: If a request to disable the axis is pending, the

axis brakes at the configured emergency deceleration. The axis is

disabled after reaching standstill.

•

1: Immediate stop: If a request to disable the axis is pending, this

axis is disabled without deceleration. Pulse output is stopped imme-

diately.

•

2: Emergency stop with jerk control: If a request to disable the axis is

pending, the axis brakes at the configured emergency stop decelera-

tion. If the jerk control is activated, the configured jerk is taken into

account. The axis is disabled after reaching standstill.

Status

OUT

Bool

Status of axis enable:

• FALSE: The axis is disabled:

- The axis does not execute motion control tasks and does not ac-

cept any new tasks (exception: MC_Reset task).

- The axis is not homed.

- Upon disabling, the status does not change to FALSE until the

axis reaches a standstill.

• TRUE: The axis is enabled:

- The axis is ready to execute motion control tasks.

- Upon axis enabling, the status does not change to TRUE until

the signal "Drive ready" is pending. If the "Drive ready" drive in-

terface was not configured in the axis configuration, the status

changes to TRUE immediately.

Busy

OUT

Bool

FALSE: MC_Power is not active.

TRUE: MC_Power is active.

Error

OUT

Bool

FALSE: No error

TRUE: An error has occurred in motion control instruction "MC_Power"

or in the associated technology object. The cause of the error can be

found in parameters "ErrorID" and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

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10.7 Motion control instructions

①

An axis is enabled and then disabled again. After the drive has signaled "Drive ready" back to the CPU, the suc-

cessful enable can be read out via "Status_1".

②

Following an axis enable, an error has occurred that caused the axis to be disabled. The error is eliminated and

acknowledged with "MC_Reset". The axis is then enabled again.

To enable an axis with configured drive interface, follow these steps:

1. Check the requirements indicated above.

2. Initialize input parameter "StopMode" with the desired value. Set input parameter

"Enable" to TRUE.

The enable output for "Drive enabled" changes to TRUE to enable the power to the drive.

The CPU waits for the "Drive ready" signal of the drive.

When the "Drive ready" signal is available at the configured ready input of the CPU, the

axis becomes enabled. Output parameter "Status" and technology object tag <Axis

name>.StatusBits.Enable indicates the value TRUE.

To enable an axis without configured drive interface, follow these steps:

1. Check the requirements indicated above.

2. Initialize input parameter "StopMode" with the desired value. Set input parameter

"Enable" to TRUE. The axis is enabled. Output parameter "Status" and technology object

tag <Axis name>.StatusBits.Enable indicate the value TRUE.

To disable an axis, follow these steps:

1. Bring the axis to a standstill.

You can identify when the axis is at a standstill in technology object tag <Axis

name>.StatusBits.StandStill.

2. Set input parameter "Enable" to FALSE after standstill is reached.

3. If output parameters "Busy" and "Status" and technology object tag <Axis

name>.StatusBits.Enable indicate the value FALSE, disabling of the axis is complete.

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10.7 Motion control instructions

10.7.3

MC_Reset (Confirm error) instruction

Table 10- 29 MC_Reset instruction

LAD / FBD

SCL

Description

"MC_Reset_DB"(

Use the MC_Reset instruction to acknowledge

Axis:=_multi_fb_in_,

"Operating error with axis stop" and "Configura-

Execute:=_bool_in_,

tion error". The errors that require acknowl-

Restart:=_bool_in_,

edgement can be found in the "List of ErrorIDs

and ErrorInfos" under "Remedy".

Done=>_bool_out_,

Busy=>_bool_out_,

Before using the MC_Reset instruction, you

Error=>_bool_out_,

must have eliminated the cause of a pending

configuration error requiring acknowledgement

ErrorID=>_word_out_,

(for example, by changing an invalid accelera-

ErrorInfo=>_word_out_);

tion value in "Axis" technology object to a valid

value).

As of V3.0 and later, the Restart command

allows the axis configuration to be downloaded

to the work memory in the RUN operating

mode.

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_Reset_DB" is the name of the instance DB.

The MC_Reset task cannot be aborted by any other motion control task. The new MC_Reset

task does not abort any other active motion control tasks.

Table 10- 30 Parameters of the MC_Reset instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge

Restart

IN

Bool

TRUE = Download the axis configuration from the load memory to the

work memory. The command can only be executed when the axis is

disabled.

FALSE = Acknowledges pending errors

Done

OUT

Bool

TRUE = Error has been acknowledged.

Busy

OUT

Bool

TRUE = The task is being executed.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The

cause of the error can be found in parameters "ErrorID" and "ErrorIn-

fo".

ErrorID

OUTP

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

To acknowledge an error with MC_Reset, follow these steps:

1. Check the requirements indicated above.

2. Start the acknowledgement of the error with a rising edge at the Execute input parameter.

3. The error has been acknowledged when Done equals TRUE and the technology object

tag <Axis name>.StatusBits.Error equals FALSE.

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10.7 Motion control instructions

10.7.4

MC_Home (Home axis) instruction

Table 10- 31 MC_Home instruction

LAD / FBD

SCL

Description

"MC_Home_DB"(

Use the MC_Home instruction to match

Axis:=_multi_fb_in_,

the axis coordinates to the real, physical

Execute:=_bool_in_,

drive position. Homing is required for

Position:=_real_in_,

absolute positioning of the axis:

Mode:=_int_in_,

In order to use the MC_Home instruction,

Done=>_bool_out_,

the axis must first be enabled.

Busy=>_bool_out_,

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_Home_DB" is the name of the instance DB.

The following types of homing are available:

● Direct homing absolute (Mode = 0): The current axis position is set to the value of

parameter "Position".

● Direct homing relative (Mode = 1): The current axis position is offset by the value of

parameter "Position".

● Passive homing (Mode = 2): During passive homing, the MC_Home instruction does not

carry out any homing motion. The traversing motion required for this step must be

implemented by the user via other motion control instructions. When the reference point

switch is detected, the axis is homed.

● Active homing (Mode = 3): The homing procedure is executed automatically.

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Table 10- 32 Parameters for the MC_Home instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_PTO

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge

Position

IN

Real

• Mode = 0, 2, and 3 (Absolute position of axis after comple-

tion of the homing operation)

• Mode = 1 (Correction value for the current axis position)

Limit values: -1.0e¹² ≤ Position ≤ 1.0e¹²

Mode

IN

Int

Homing mode

•

0: Direct homing absolute

New axis position is the position value of parameter "Posi-

tion".

•

1: Direct homing relative

New axis position is the current axis position + position

value of parameter "Position".

•

2: Passive homing

Homing according to the axis configuration. Following

homing, the value of parameter "Position" is set as the

new axis position.

•

3: Active homing

Reference point approach in accordance with the axis

configuration. Following homing, the value of parameter

"Position" is set as the new axis position.

Done

OUT

Bool

TRUE = Task completed

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another

task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task.

The cause of the error can be found in parameters "ErrorID"

and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

Note

Axis homing is lost under the following conditions

• Disabling of axis by the MC_Power instruction

• Switchover between automatic control and manual control

• Upon start of active homing (After successful completion of the homing operation, axis

homing is available again.)

• After power-cycling the CPU

• After CPU restart (RUN-to-STOP or STOP-to-RUN)

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10.7 Motion control instructions

To home the axis, follow these steps:

1. Check the requirements indicated above.

2. Initialize the necessary input parameters with values, and start the homing operation with

a rising edge at input parameter "Execute".

3. If output parameter "Done" and technology object tag <Axis

name>.StatusBits.HomingDone indicate the value TRUE, homing is complete.

Table 10- 33

Override response

Mode

Description

0 or 1

The MC_Home task cannot be aborted by any other motion control task. The new MC_Home task does not

abort any active motion control tasks. Position-related motion tasks are resumed after homing according to

the new homing position (value at the Position input parameter).

2

The MC_Home task can be aborted by the following motion control tasks:

MC_Home task Mode = 2, 3: The new MC_Home task aborts the following active motion control task.

MC_Home task Mode = 2: Position-related motion tasks are resumed after homing according to the new

homing position (value at the Position input parameter).

3

The MC_Home task can be aborted by the following

The new MC_Home task aborts the following active

motion control tasks:

motion control tasks:

• MC_Home Mode = 3

• MC_Home Mode = 2, 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

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10.7 Motion control instructions

10.7.5

MC_Halt (Pause axis) instruction

Table 10- 34 MC_Halt instruction

LAD / FBD

SCL

Description

"MC_Halt_DB"(

Use the MC_Halt instruction to stop all

Axis:=_multi_fb_in_,

motion and to bring the axis to a stand-

Execute:=_bool_in_,

still. The stand-still position is not defined.

Done=>_bool_out_,

In order to use the MC_Halt instruction,

Busy=>_bool_out_,

the axis must first be enabled.

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_Halt_DB" is the name of the instance DB.

Table 10- 35 Parameters for the MC_Halt instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge

Done

OUT

Bool

TRUE = Zero velocity reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another

task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task.

The cause of the error can be found in parameters "ErrorID"

and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error"

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and Decelera-

tion = 5.0

① The axis is braked by an MC_Halt task until it comes to a standstill. The axis standstill is signaled via "Done_2".

② While an MC_Halt task is braking the axis, this task is aborted by another motion task. The abort is signaled via

"Abort_2".

Override response

The MC_Halt task can be aborted by the

The new MC_Halt task aborts the following

following motion control tasks:

active motion control tasks:

• MC_Home Mode = 3

• MC_Home Mode = 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

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10.7 Motion control instructions

10.7.6

MC_MoveAbsolute (Position axis absolutely) instruction

Table 10- 36 MC_MoveAbsolute instruction

LAD / FBD

SCL

Description

"MC_MoveAbsolute_DB"(

Use the MC_MoveAbsolute in-

Axis:=_multi_fb_in_,

struction to start a positioning

Execute:=_bool_in_,

motion of the axis to an absolute

Position:=_real_in_,

position.

Velocity:=_real_in_,

In order to use the

Done=>_bool_out_,

MC_MoveAbsolute instruction, the

Busy=>_bool_out_,

axis must first be enabled and also

must be homed.

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_MoveAbsolute_DB" is the name of the instance DB.

Table 10- 37 Parameters for the MC_MoveAbsolute instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge (Default value: False)

Position

IN

Real

Absolute target position (Default value: 0.0)

Limit values: -1.0e¹² ≤ Position ≤ 1.0e¹²

Velocity

IN

Real

Velocity of axis (Default value: 10.0)

This velocity is not always reached because of the configured accel-

eration and deceleration and the target position to be approached.

Limit values: Start/stop velocity ≤ Velocity ≤ maximum velocity

Done

OUT

Bool

TRUE = Absolute target position reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The

cause of the error can be found in parameters "ErrorID" and "ErrorIn-

fo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and Decelera-

tion = 10.0

① An axis is moved to absolute position 1000.0 with a MC_MoveAbsolute task. When the axis reaches the target

position, this is signaled via "Done_1". When "Done_1" = TRUE, another MC_MoveAbsolute task, with target posi-

tion 1500.0, is started. Because of the response times (e.g., cycle time of user program, etc.), the axis comes to a

standstill briefly (see zoomed-in detail). When the axis reaches the new target position, this is signaled via

"Done_2".

② An active MC_MoveAbsolute task is aborted by another MC_MoveAbsolute task. The abort is signaled via

"Abort_1". The axis is then moved at the new velocity to the new target position 1500.0. When the new target posi-

tion is reached, this is signaled via "Done_2".

Override response

The MC_MoveAbsolute task can be abort-

The new MC_MoveAbsolute task aborts

ed by the following motion control tasks:

the following active motion control tasks:

• MC_Home Mode = 3

• MC_Home Mode = 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

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10.7 Motion control instructions

10.7.7

MC_MoveRelative (Position axis relatively) instruction

Table 10- 38 MC_MoveRelative instruction

LAD / FBD

SCL

Description

"MC_MoveRelative_DB"(

Use the MC_MoveRelative instruc-

Axis:=_multi_fb_in_,

tion to start a positioning motion

Execute:=_bool_in_,

relative to the start position.

Distance:=_real_in_,

In order to use the

Velocity:=_real_in_,

MC_MoveRelative instruction, the

Done=>_bool_out_,

axis must first be enabled.

Busy=>_bool_out_,

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_MoveRelative_DB " is the name of the instance DB.

Table 10- 39 Parameters for the MC_MoveRelative instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge (Default value: False)

Distance

IN

Real

Travel distance for the positioning operation (Default value: 0.0)

Limit values: -1.0e¹² ≤ Distance ≤ 1.0e¹²

Velocity

IN

Real

Velocity of axis (Default value: 10.0)

This velocity is not always reached on account of the configured

acceleration and deceleration and the distance to be traveled.

Limit values: Start/stop velocity ≤ Velocity ≤ maximum velocity

Done

OUT

Bool

TRUE = Target position reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The

cause of the error can be found in parameters "ErrorID" and "Error-

Info".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and Decelera-

tion = 10.0

① The axis is moved by an MC_MoveRelative task by the distance ("Distance") 1000.0. When the axis reaches the

target position, this is signaled via "Done_1". When "Done_1" = TRUE, another MC_MoveRelative task, with travel

distance 500.0, is started. Because of the response times (for example, cycle time of user program), the axis

comes to a standstill briefly (see zoomed-in detail). When the axis reaches the new target position, this is signaled

via "Done_2".

② An active MC_MoveRelative task is aborted by another MC_MoveRelative task. The abort is signaled via

"Abort_1". The axis is then moved at the new velocity by the new distance ("Distance") 500.0. When the new target

position is reached, this is signaled via "Done_2".

Override response

The MC_MoveRelative task can be aborted

The new MC_MoveRelative task aborts the

by the following motion control tasks:

following active motion control tasks:

• MC_Home Mode = 3

• MC_Home Mode = 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

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10.7.8

MC_MoveVelocity (Move axis at predefined velocity) instruction

Table 10- 40 MC_MoveVelocity instruction

LAD / FBD

SCL

Description

"MC_MoveVelocity_DB"(

Use the MC_MoveVelocity instruc-

Axis:=_multi_fb_in_,

tion to move the axis constantly at

Execute:=_bool_in_,

the specified velocity.

Velocity:=_real_in_,

In order to use the

Direction:=_int_in_,

MC_MoveVelocity instruction, the

Current:=_bool_in_,

axis must first be enabled.

InVelocity=>_bool_out_,

Busy=>_bool_out_,

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_MoveVelocity_DB " is the name of the instance DB.

Table 10- 41 Parameters for the MC_MoveVelocity instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the task with a positive edge (Default value: False)

Velocity

IN

Real

Velocity specification for axis motion (Default value: 10.0)

Limit values: Start/stop velocity ≤ |Velocity| ≤ maximum velocity

(Velocity = 0.0 is allowed)

Direction

IN

Int

Direction specification:

•

0: Direction of rotation corresponds to the sign of the value in

parameter "Velocity" (Default value)

•

1: Positive direction of rotation (The sign of the value in param-

eter "Velocity" is ignored.)

•

2: Negative direction of rotation (The sign of the value in pa-

rameter "Velocity" is ignored.)

Current

IN

Bool

Maintain current velocity:

• FALSE: "Maintain current velocity" is deactivated. The values

of parameters "Velocity" and "Direction" are used. (Default val-

ue)

• TRUE: "Maintain current velocity" is activated. The values in

parameters "Velocity" and "Direction" are not taken into ac-

count.

When the axis resumes motion at the current velocity, the "In-

Velocity" parameter returns the value TRUE.

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Parameter and type

Data type

Description

InVelocity

OUT

Bool

TRUE:

• If "Current" = FALSE: The velocity specified in parameter "Ve-

locity" was reached.

• If "Current" = TRUE: The axis travels at the current velocity at

the start time.

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The

cause of the error can be found in parameters "ErrorID" and "Error-

Info".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and Decelera-

tion = 10.0

① An active MC_MoveVelocity task signals via "InVel_1" that its target velocity has been reached. It is then aborted

by another MC_MoveVelocity task. The abort is signaled via "Abort_1". When the new target velocity 15.0 is

reached, this is signaled via "InVel_2". The axis then continues moving at the new constant velocity.

② An active MC_MoveVelocity task is aborted by another MC_MoveVelocity task prior to reaching its target velocity.

The abort is signaled via "Abort_1". When the new target velocity 15.0 is reached, this is signaled via "InVel_2".

The axis then continues moving at the new constant velocity.

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10.7 Motion control instructions

10.7.9

MC_MoveJog (Move axis in jog mode) instruction

Table 10- 42 MC_MoveJog instruction

LAD / FBD

SCL

Description

"MC_MoveJog_DB"(

Use the MC_MoveJog instruction to move

Axis:=_multi_fb_in_,

the axis constantly at the specified veloci-

JogForward:=_bool_in_,

ty in jog mode. This instruction is typically

JogBackward:=_bool_in_,

used for testing and commissioning pur-

poses.

Velocity:=_real_in_,

InVelocity=>_bool_out_,

In order to use the MC_MoveJog instruc-

Busy=>_bool_out_,

tion, the axis must first be enabled.

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_MoveJog_DB " is the name of the instance DB.

Table 10- 43 Parameters for the MC_MoveJog instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

JogForward¹

IN

Bool

As long as the parameter is TRUE, the axis moves in the positive

direction at the velocity specified in parameter "Velocity". The sign of

the value in parameter "Velocity" is ignored. (Default value: False)

JogBackward¹

IN

Bool

As long as the parameter is TRUE, the axis moves in the negative

direction at the velocity specified in parameter "Velocity". The sign of

the value in parameter "Velocity" is ignored. (Default value: False)

Velocity

IN

Real

Preset velocity for jog mode (Default value: 10.0)

Limit values: Start/stop velocity ≤ |Velocity| ≤ maximum velocity

InVelocity

OUT

Bool

TRUE = The velocity specified in parameter "Velocity" was reached.

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The

cause of the error can be found in parameters "ErrorID" and "ErrorIn-

fo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

1

If both the JogForward and JogBackward parameters are simultaneously TRUE, the axis stops with the configured

deceleration. An error is indicated in parameters "Error", "ErrorID", and "ErrorInfo".

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and Decelera-

tion = 5.0

① The axis is moved in the positive direction in jog mode via "Jog_F". When the target velocity 50.0 is reached, this is

signaled via "InVelo_1". The axis brakes to a standstill again after Jog_F is reset.

② The axis is moved in the negative direction in jog mode via "Jog_B". When the target velocity 50.0 is reached, this

is signaled via "InVelo_1". The axis brakes to a standstill again after Jog_B is reset.

Override response

The MC_MoveJog task can be aborted by

The new MC_MoveJog task aborts the

the following motion control tasks:

following active motion control tasks:

• MC_Home Mode = 3

• MC_Home Mode = 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

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10.7 Motion control instructions

10.7.10

MC_CommandTable (Run axis commans as movement sequence) instruction

Table 10- 44 MC_CommandTable instruction

LAD / FBD

SCL

Description

"MC_CommandTable_DB"(

Executes a series of individual

Axis:=_multi_fb_in_,

motions for a motor control axis

CommandTable:=_multi_fb_in_,

that can combine into a move-

Execute:=_bool_in_,

ment sequence.

StartIndex:=_uint_in_,

Individual motions are configured

EndIndex:=_uint_in_,

in a technology object command

Done=>_bool_out_,

table for pulse train output

(TO_CommandTable_PTO).

Busy=>_bool_out_,

CommandAborted=>_bool_out_,

Error=>_bool_out_,

ErrorID=>_word_out_,

ErrorInfo=>_word_out_,

CurrentIndex=>_uint_out_,

Code=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_CommandTable_DB " is the name of the instance DB.

Table 10- 45 Parameters for the MC_CommandTable instruction

Parameter and type

Data type

Initial value

Description

Axis

IN

TO_Axis_1

-

Axis technology object

Table

IN

TO_CommandTable_1

-

Command table technology object

Execute

IN

Bool

FALSE

Start job with rising edge

StartIndex

IN

Int

1

Start command table processing with this step

Limits: 1 ≤ StartIndex ≤ EndIndex

EndIndex

IN

Int

32

End command table processing with this step

Limits: StartIndex ≤ EndIndex ≤ 32

Done

OUT

Bool

FALSE

MC_CommandTable processing completed suc-

cessfully

Busy

OUT

Bool

FALSE

Operation in progress

CommandAborted

OUT

Bool

FALSE

The task was aborted during processing by anoth-

er task.

Error

OUT

Bool

FALSE

An error occurred during processing. The cause is

indicated by the parameters ErrorID and ErrorInfo.

ErrorID

OUT

Word

16#0000

Error identifier

ErrorInfo

OUT

Word

16#0000

Error information

Step

OUT

Int

0

Step currently in process

Code

OUT

Word

16#0000

User defined identifier of the step currently in pro-

cess

You can create the desired movement sequence in the "Command Table" configuration

window and check the result against the graphic view in the trend diagram.

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10.7 Motion control instructions

You can select the command types that are to be used for processing the command table.

Up to 32 jobs can be entered. The commands are processed in sequence.

Table 10- 46 MC_CommandTable command types

Command type

Description

Empty

The empty serves as a placeholder for any commands to be added. The empty entry is

ignored when the command table is processed

Halt

Pause axis.

Note: The command only takes place after a "Velocity setpoint" command.

Positioning Relative

Positions the axis based upon distance. The command moves the axis by the given dis-

tance and velocity.

Positioning Absolute

Positions the axis based upon location. The command moves the axis to the given loca-

tion, using the velocity specified.

Velocity setpoint

Moves the axis at the given velocity.

Wait

Waits until the given period is over. "Wait" does not stop an active traversing motion.

Separator

Adds a "Separator" line above the selected line. The separator line allows more than one

profile to be defined in a single command table.

Prerequisites for MC_CommandTable execution:

● The technology object TO_Axis_PTO V2.0 must be correctly configured.

● The technology object TO_CommandTable_PTO must be correctly configured.

● The axis must be released.

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10.7 Motion control instructions

Override response

The MC_CommandTable task can be

The new MC_CommandTable task aborts the

aborted by the following motion control

following active motion control tasks:

tasks:

• MC_Home Mode = 3

• MC_Home Mode = 3

• MC_Halt

• MC_Halt

• MC_MoveAbsolute

• MC_MoveAbsolute

• MC_MoveRelative

• MC_MoveRelative

• MC_MoveVelocity

• MC_MoveVelocity

• MC_MoveJog

• MC_MoveJog

• MC_CommandTable

• MC_CommandTable

• The current motion control job with the

launch of the first "Positioning Relative",

"Positioning Absolute", "Velocity setpoint"

or "Halt" command

10.7.11

MC_ChangeDynamic (Change dynamc settings for the axis) instruction

Table 10- 47 MC_ChangeDynamic instruction

LAD / FBD

SCL

Description

"MC_ChangeDynamic_DB"(

Changes the dynamic settings of

Execute:=_bool_in_,

a motion control axis:

ChangeRampUp:=_bool_in_,

• Change the ramp-up time

RampUpTime:=_real_in_,

(acceleration) value

ChangeRampDown:=_bool_in_,

• Change the ramp-down time

RampDownTime:=_real_in_,

(deceleration) value

ChangeEmergency:=_bool_in_,

EmergencyRampTime:=_real_in_,

• Change the emergency stop

ChangeJerkTime:=_bool_in_,

ramp-down time (emergency

JerkTime:=_real_in_,

stop deceleration) value

Done=>_bool_out_,

• Change the smoothing time

Error=>_bool_out_,

(jerk) value

ErrorID=>_word_out_,

ErrorInfo=>_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_ChangeDynamic_DB " is the name of the instance DB.

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10.7 Motion control instructions

Table 10- 48 Parameters for the MC_ChangeDynamic instruction

Parameter and type

Data type

Description

Axis

IN

TO_Axis_1

Axis technology object

Execute

IN

Bool

Start of the command with a positive edge. Default value:

FALSE

ChangeRampUp

IN

Bool

TRUE = Change ramp-up time in line with input parameter

"RampUpTime". Default value: FALSE

RampUpTime

IN

Real

Time (in seconds) to accelerate from standstill to the configured

maximum velocity without jerk limit. Default value: 5.00

The change will influence the tag <Axis name>. Con-

fig.DynamicDefaults.Acceleration. The effectiveness of the

change is shown in the description of this tag.

ChangeRampDown

IN

Bool

TRUE = Change ramp-down time in line with input parameter

"RampDownTime". Default value: FALSE

RampDownTime

IN

Real

Time (in seconds) to decelerate axis from the configured maxi-

mum velocity to standstill without jerk limiter. Default value: 5.00

The change will influence the tag <Axis name>. Con-

fig.DynamicDefaults.Deceleration. The effectiveness of the

change is shown in the description of this tag.

ChangeEmergency

IN

Bool

TRUE = Change emergency stop ramp-down time in line with

input parameter "EmergencyRampTime" Default value: FALSE

EmergencyRampTime

IN

Real

Time (in seconds) to decelerate the axis from configured maxi-

mum velocity to standstill without jerk limiter in emergency stop

mode. Default value: 2.00

The change will influence the tag <Axis name>. Con-

fig.DynamicDefaults.EmergencyDeceleration. The effectiveness

of the change is shown in the description of this tag.

ChangeJerkTime

IN

Bool

TRUE = Change smoothing time according to the input parame-

ter "JerkTime". Default value: FALSE

JerkTime

IN

Real

Smoothing time (in seconds) used for the axis acceleration and

deceleration ramps. Default value: 0.25

The change will influence the tag <Axis name>. Con-

fig.DynamicDefaults.Jerk. The effectiveness of the change is

shown in the description of this tag.

Done

OUT

Bool

TRUE = The changed values have been written to the technolo-

gy data block. The description of the tags will show when the

change becomes effective. Default value: FALSE

Error

OUT

Bool

TRUE = An error occurred during execution of the command.

The cause of the error can be found in parameters "ErrorID" and

"ErrorInfo". Default value: FALSE

ErrorID

OUT

Word

Error identifier. Default value: 16#0000

ErrorInfo

IN

Word

Error information. Default value: 16#0000

Prerequisites for MC_ ChangeDynamic execution:

● The technology object TO_Axis_PTO V2.0 must be correctly configured.

● The axis must be released.

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10.7 Motion control instructions

Override response

An MC_ChangeDynamic command cannot be aborted by any other Motion Control

command.

A new MC_ChangeDynamic command does not abort any active Motion Control jobs.

Note

The input parameters "RampUpTime", "RampDownTime", "EmergencyRampTime" and

"RoundingOffTime" can be specified with values that makes the resultant axis parameters

"acceleration", "delay", "emergency stop-delay" and "jerk" outside the permissible limits.

Make sure you keep the MC_ChangeDynamic parameters within the limits of the dynamic

configuration settings for the axis technology object.

10.7.12

MC_WriteParam (write parameters of a technology object) instruction

You use the MC_WriteParam instruction to write a select number of parameters to change

the functionality of the axis from the user program.

Table 10- 49 MC_WriteParam instruction

LAD / FBD

SCL

Description

"MC_WriteParam_DB"(

You use the MC_WriteParam

Parameter:=_variant_in_,

instruction to write to public pa-

Value:=_variant_in_,

rameters (for example, accelera-

Execute:=_bool_in_,

tion and user DB values).

Done:=_bool_out_,

Error:=_real_out_,

ErrorID:=_word_out_,

ErrorInfo:=_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_WriteParam_DB" is the name of the instance DB.

You can write to the parameters that are public. You cannot write to "MotionStatus" and

"StatusBits". The valid parameters are listed in the table below:

Writeable parameter name

Writeable parameter name

Actor.InverseDirection

DynamicDefaults.Acceleration

Actor.DirectionMode

DynamicDefaults.Deceleration

Actor.DriveParameter.PulsesPerDriveRevolution

DynamicDefaults.Jerk

Sensor[1].ActiveHoming.Mode

DynamicDefaults.EmergencyDeceleration

Sensor[1].ActiveHoming.SideInput

PositionLimitsHW.Active

Sensor[1].ActiveHoming.Offset

PositionLimitsHW.MaxSwitchedLevel

Sensor[1].ActiveHoming.SwitchedLevel

PositionLimitsHW.MinSwitchedLevel

Sensor[1].PassiveHoming.Mode

PositionLimitsSW.Active

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10.7 Motion control instructions

Writeable parameter name

Writeable parameter name

Sensor[1].PassiveHoming.SideInput

PositionLimitsSW.MinPosition

Sensor[1].PassiveHoming.SwitchedLevel

PositionLimitsSW.MaxPosition

Units.LengthUnit

Homing.AutoReversal

Mechanics.LeadScrew

Homing.ApproachDirection

DynamicLimits.MinVelocity

Homing.ApproachVelocity

DynamicLimits.MaxVelocity

Homing.ReferencingVelocity

Table 10- 50 Parameters for the MC_WriteParam instruction

Parameter and type

Data type

Description

PARAMNAME

IN

Variant

Name of parameter where value is written

VALUE

IN

Variant

Value to write to assigned parameter

EXECUTE

IN

Bool

Start the instruction. Default value: FALSE

DONE

OUT

Bool

Value has been written. Default value: FALSE

BUSY

OUT

Bool

If TRUE, the instruction is operating. Default value: FALSE

ERROR

OUT

Real

If TRUE, an error occurred. Default value: FALSE

ERRORID

OUT

Word

ID of the error

ERRORINFO

OUT

Word

Related information to the ERRORID

Table 10- 51 Condition codes for ERRORID and ERRORINFO

ERRORID

ERRORINFO

Description

(W#16#...)

(W#16#...)

0

0

Successful change of an Axis TO-DB parameter

8410[1]

0028[1]

Set an invalid parameter (Axis TO-DB parameter with incorrect length)

8410[1]

0029[1]

Set an invalid parameter (no Axis TO-DB parameter)

8410[1]

002B[1]

Set an Invalid parameter (read-only Axis TO-DB parameter)

8410[1]

002C[1]

Set a valid parameter, but axis is not disabled

Config

Config

Set a valid parameter (public read-only Axis TO-DB parameter) out-of-range

Error[2]

Error[2]

Config

Config

Set a valid parameter (public Axis TO-DB parameter) out-of-range

Error[3]

Error[3]

[1] Error at MC_WriteParam

[2] Error at MC_Power

[3] Error at MC_Power and MC_MoveXXX or MC_CommandTable

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10.7 Motion control instructions

10.7.13

MC_ReadParam instruction (read parameters of a technology object) instruction

You use the MC_ReadParam instruction to read a select number of parameters that indicate

the current position, velocity, and so forth of the axis defined in the Axis input.

Table 10- 52 MC_ReadParam instruction

LAD / FBD

SCL

Description

"MC_ReadParam_DB"(

You use the MC_ReadParam

Enable:=_bool_in_,

instruction to read single status

Parameter:=_variant_in_,

values, independent of the cycle

Value:=_variant_in_out_,

control point.

Valid:=_bool_out_,

Busy:=_bool_out_,

Error:=_real_out_,

ErrorID:=_word_out_,

ErrorInfo:=_word_out_);

1

STEP 7 automatically creates the DB when you insert the instruction.

2

In the SCL example, "MC_ReadParam_DB " is the name of the instance DB.

The MC_ReadParam instruction works on an enable behavior. As long as the input "Enable"

is true the instruction reads the specified "Parameter" to the "Value" storage location.

The "MotionStatus" "Position" value updates at each Cycle Control Point (CCP) based upon

the current HSC value.

The "MotionStatus" "Velocity" value is the command velocity at the end of the current

segment (updated ~10ms). The MC_ReadParam can also read this value.

If an error occurs, the instruction switches to an error state that can only be reset by a new

rising edge at the input "Enable".

Table 10- 53 Parameters for the MC_ReadParam instruction

Parameter and type

Data type

Description

ENABLE

IN

Bool

Start the instruction. Default value: FALSE

PARAMETER

IN

Variant

Pointer to the TO-parameter that is to be read

VALID

OUT

Bool

If TRUE, the value has been read. Default value: FALSE

BUSY

OUT

Bool

If TRUE, the instruction is operating. Default value: FALSE

ERROR

OUT

Real

If TRUE, an error occurred. Default value: FALSE

ERRORID

OUT

Word

ID of the error. Default value: 0

ERRORINFO

OUT

Word

Related information to the ERRORID. Default value: 0

VALUE

INOUT

Variant

Pointer to the location where the read value is stored

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10.7 Motion control instructions

Table 10- 54 Condition codes for ERRORID and ERRORINFO

ERRORID

ERRORINFO

Description

(W#16#...)

(W#16#...)

0

0

Successful read of a parameter

8410

0028

Invalid parameter (incorrect length)

8410

0029

Invalid parameter (no TO-DB)

8410

0030

Invalid parameter (not readable)

8411

0032

Invalid parameter (wrong value)

TO parameters

The axis "MotionStatus" consists of four values. You will want to monitor changes in these

values, which can be read while the program is running:

Variable name

Data type

Readable through

MC_ReadParam

MotionStatus:

Structure

No

• Position

REAL

Yes

• Velocity

REAL

Yes

• Distance

REAL

Yes

• TargetPosition

REAL

Yes

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Easy to use the online tools

11

11.1

Going online and connecting to a CPU

You must establish an online connection between the programming device and CPU for

loading programs and project engineering data as well as for activities such as the following:

● Testing user programs

● Displaying and changing the operating mode of the CPU (Page 336)

● Displaying and setting the date and time of day of the CPU (Page 346)

● Displaying the module information

● Comparing and synchronizing (Page 345) offline to online program blocks

● Uploading and downloading program blocks

● Displaying diagnostics and the diagnostics buffer (Page 346)

● Using a watch table (Page 338) to test the user program by monitoring and modifying

values

● Using a force table to force values in the CPU (Page 340)

To establish an online connection to a configured CPU, click

the CPU from the Project Navigation tree and click the "Go

online" button from the Project View:

If this is the first time to go

online with this CPU, you

must select the type of PG/PC

interface and the specific

PG/PC interface from the Go

Online dialog before estab-

lishing an online connection to

a CPU found on that inter-

face.

You have now connected your programming device to the CPU. The orange color frames

indicate an online connection. You can now use the Online & diagnostics tools from the

Project tree and the Online tools task card.

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Easy to use the online tools

11.2 Interacting with the online CPU

11.2

Interacting with the online CPU

The "Online tools" task card in the project view displays an operator panel that shows the

operating mode of the online CPU. The operator panel also allows you to change the

operating mode of the online CPU. Use the button on the operator panel to change the

operating mode (STOP or RUN). The operator panel also provides an MRES button for

resetting the memory.

The color of the RUN/STOP indicator shows the current operating

mode of the CPU: yellow indicates STOP mode, and green indicates

RUN mode.

To use the operator panel, you must establish an online connection between STEP 7 and

the CPU. After you select the CPU in the device configuration or display a code block in the

online CPU, you can display the operator panel from the "Online tools" task card.

You can monitor the cycle time of an online CPU.

You can also view the memory usage of the CPU.

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Easy to use the online tools

11.3 Going online to monitor the values in the CPU

11.3

Going online to monitor the values in the CPU

To monitor the tags, you must have an online connection to the CPU. Simply click the "Go

online" button in the toolbar.

When you have connected to the CPU, STEP 7 turns the headers of

the work areas orange.

The project tree displays a comparison of the offline project and the

online CPU. A green circle means that the CPU and the project are

synchronized, meaning that both have the same configuration and

user program.

Tag tables show the tags. Watch tables can also show the tags, as

well as direct addresses.

To monitor the execution of the user program and to display the values of the tags,

click the "Monitor all" button in the toolbar.

The "Monitor value" field shows the value for each tag.

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Easy to use the online tools

11.4 Displaying status of the user program is easy

11.4

Displaying status of the user program is easy

You can monitor the status of up to 50 tags in the LAD and FBD program editors. Use the

editor bar to display the LAD editor. The editor bar allows you to change the view between

the open editors without having to open or close the editors.

In the toolbar of the program editor, click the "Monitoring on/off" button to display the status

of your user program.

The network in the program editor displays power flow in green.

You can also right-click on the instruction or parameter to modify the value for the instruction.

11.5

Using a watch table for monitoring the CPU

A watch table allows you to monitor or modify data points while the CPU executes your user

program. These data points can be inputs (I), outputs (Q), M memory, a DB, or peripheral

inputs (such as "On:P" or "I 3.4:P"). You cannot accurately monitor the physical outputs

(such as Q0.0:P) because the monitor function can only display the last value written from Q

memory and does not read the actual value from the physical outputs.

The monitoring function does not change the program sequence. It presents you with

information about the program sequence and the data of the program in the CPU. You can

also use the "Modify value" function to test the execution of your user program.

Note

The digital I/O points used by the high-speed counter (HSC), pulse-width modulation (PWM),

and pulse-train output (PTO) devices are assigned during device configuration. When digital

I/O point addresses are assigned to these devices, the values of the assigned I/O point

addresses cannot be modified by the "Force" function of the watch table.

With a watch table, you can monitor or modify the values of the individual tags, choosing

from the following options:

● At the beginning or the end of the scan cycle

● When the CPU changes to STOP mode

● "Permanently" (with the value not being reset after a STOP to RUN transition)

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Easy to use the online tools

11.5 Using a watch table for monitoring the CPU

To create a watch table:

1. Double-click "Add new watch table" to open a new

watch table.

2. Enter the tag name to add a tag to the watch

table.

To monitor the tags, you must have an online connection to the CPU. The following options

are available for modifying tags:

● "Modify now" immediately changes the value for the selected addresses for one scan

cycle.

● "Modify with trigger" changes the values for the selected addresses.

This function does not provide feedback to indicate that the selected addresses were

actually modified. If feedback of the change is required, use the "Modify now" function.

● "Enable peripheral outputs" allows you to turn on the peripheral outputs when the CPU is

in STOP mode. This feature is useful for testing the wiring of the output modules.

The various functions can be selected using the buttons at the top of a watch table. Enter the

tag name to monitor and select a display format from the dropdown selection. With an online

connection to the CPU, clicking the "Monitor" button displays the actual value of the data

point in the "Monitor value" field.

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Easy to use the online tools

11.6 Using the force table

11.6

Using the force table

A force table provides a "force" function that overwrites the value for an input or output point

to a specified value for the peripheral input or peripheral output address. The CPU applies

this forced value to the input process image prior to the execution of the user program and to

the output process image before the outputs are written to the modules.

Note

The force values are stored in the CPU and not in the force table.

You cannot force an input (or "I" address) or an output (or "Q" address). However, you can

force a peripheral input or peripheral output. The force table automatically appends a ":P" to

the address (for example: "On":P or "Run":P).

In the "Force value" cell, enter the value for the input or output to be forced. You can then

use the check box in the "Force" column to enable forcing of the input or output.

Use the "Start or replace forcing" button to force the value of the tags in the force

table. Click the "Stop forcing" button to reset the value of the tags.

In the force table, you can monitor the status of the forced value for an input. However, you

cannot monitor the forced value of an output.

You can also view the status of the forced value in the program editor.

Note

When an input or output is forced in a force table, the force actions become part of the

project configuration. If you close STEP 7, the forced elements remain active in the CPU

program until they are cleared. To clear these forced elements, you must use STEP 7 to

connect with the online CPU and then use the force table to turn off or stop the force function

for those elements.

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11.6 Using the force table

Startup

RUN

A The clearing of the I memory area is not

① While writing Q memory to the physical out-

affected by the Force function.

puts, the CPU applies the force value as the

outputs are updated.

B The initialization of the outputs values is

② When reading the physical inputs, the CPU

not affected by the Force function.

applies the force values just prior to copying

the inputs into I memory.

C During the execution of the startup OBs,

③ During the execution of the user program

the CPU applies the force value when

(program cycle OBs), the CPU applies the

the user program accesses the physical

force value when the user program accesses

input.

the physical input or writes the physical out-

put.

D The storing of interrupt events into the

④ Handling of communication requests and self-

queue is not affected.

test diagnostics are not affected by the Force

function.

E The enabling of the writing to the out-

⑤ The processing of interrupts during any part of

puts is not affected.

the scan cycle is not affected.

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11.8 Uploading elements of the project

11.8

Uploading elements of the project

You can also copy the program blocks from an online CPU or a memory card attached to

your programming device.

Prepare the offline project for the copied program blocks:

1. Add a CPU device that matches the online CPU.

2. Expand the CPU node once so that the "Program

blocks" folder is visible.

To upload the program blocks from the online CPU to the

offline project, follow these steps:

1. Click the "Program blocks" folder in the offline project.

2. Click the "Go online" button.

3. Click the "Upload" button.

4. Confirm your decision from the Upload dialog

(Page 335).

When the upload is complete, STEP 7 displays all of the

uploaded program blocks in the project.

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11.9 Comparing offline and online CPUs

11.9

Comparing offline and online CPUs

You can compare the code blocks in an online CPU with the code blocks in your project. If

the code blocks of your project do not match the code blocks of the online CPU, the

"Compare" editor allows you to synchronize your project with the online CPU by downloading

the code blocks of your project to the CPU, or by deleting blocks from the project that do not

exist in the online CPU.

Select the CPU in your project.

Use the "Compare Offline/online" command to open the "Com-

pare" editor. (Access the command either from the "Tools"

menu or by right-clicking the CPU in your project.)

Click in the "Action" column for an object to

select whether to delete the object, take no

action, or download the object to the device.

Click the "Synchronize" button to load the code

blocks.

Right-click an object in the "Compare to" column and

select "Start detailed comparison" button to show the

code blocks side-by-side.

The detailed comparison highlights the differences

between the code blocks of online CPU and the code

blocks of the CPU in your project.

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11.10 Displaying the diagnostic events

11.10

Displaying the diagnostic events

The CPU provides a diagnostic buffer that contains an entry for each diagnostic event, such

as transition of the CPU operating mode or errors detected by the CPU or modules. To

access the diagnostic buffer, you must be online.

Each entry includes a date and time the event occurred, an event category, and an event

description. The entries are displayed in chronological order, with the most recent event at

the top.

While the CPU maintains power, up to

50 most recent events are available in

this log. When the log is full, a new

event replaces the oldest event in the

log.

When power is lost, the ten most re-

cent events are saved.

11.11

Setting the IP address and time of day

You can set the IP address and time of day in the online CPU. After accessing "Online &

diagnostics" from the Project tree for an online CPU, you can display or change the IP ad-

dress. You can also display or set the time and date parameters of the online CPU.

Note

This feature is available only for a CPU that either has only a MAC address (has not yet

been assigned an IP address) or has been reset to factory settings.

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11.12 Resetting to factory settings

11.12

Resetting to factory settings

You can reset an S7-1200 to its original factory settings under the following conditions:

● The CPU has an online connection.

● The CPU is in STOP mode.

Note

If the CPU is in RUN mode and you start the reset operation, you can place it in STOP

mode after acknowledging a confirmation prompt.

Procedure

To reset a CPU to its factory settings, follow these steps:

1. Open the Online and Diagnostics view of the CPU.

2. Select "Reset to factory settings" from the "Functions" folder.

3. Select the "Retain IP address" check box if you want to retain the IP address or the

"Delete IP address" check box if you want to delete the IP address.

4. Click the "Reset" button.

5. Acknowledge the confirmation prompt with "OK".

Result

The module switches to STOP mode if necessary, and it resets the factory settings. The

CPU perfoms the following actions:

With memory card installed in CPU

Without memory card installed in CPU

• Clears the diagnostics buffer

• Clears the diagnostics buffer

• Resets the time of day

• Resets the time of day

• Restores work memory from the memory card

• Clears the work memory and internal load

memory

• Sets all operand areas to configured initial

values

• Sets all operand areas to configured initial

values

• Sets all parameters to their configured values

• Sets all parameters to their configured values

• Retains or deletes the IP address based on

the selection you made. (The MAC address is

• Retains or deletes the IP address based on

fixed and is never changed.)¹

the selection you made. (The MAC address is

fixed and is never changed.)¹

• Deletes the control data record, if present

• Deletes the control data record, if present

1

If you selected "Retain IP address", the CPU sets the IP address, subnet mask, and router ad-

dress (if used) to the settings in your hardware configuration, unless you have modified these val-

ues from the user program or another tool, in which case the CPU restores the modified values.

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11.14 Downloading an IP address to an online CPU

11.14

Downloading an IP address to an online CPU

To assign an IP address, you must perform the following tasks:

• Configure the IP

address for the CPU

(Page 85).

• Save and download the

configuration to the

CPU.

The IP address and subnet mask for the CPU must be compatible with the IP address and

subnet mask of the programming device. Consult your network specialist for the IP address

and subnet mask for your CPU.

If the CPU has not been previously configured, you can also

use "Online access" to set the IP address.

An IP address that you have downloaded with the device con-

figuration will not be lost on a power cycle of the PLC.

After you have downloaded the device configuration with the IP address, you can see the IP

address under the "Online access" folder.

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11.15 Using the "unspecified CPU" to upload the hardware configuration

11.15

Using the "unspecified CPU" to upload the hardware configuration

If you have a physical CPU that you can connect to the programming device, it is easy to

upload the configuration of the hardware.

You must first connect the CPU to your programming device, and you must create a new

project.

In the device configuration (Project view or Portal view),

add a new device, but select the "unspecified CPU" in-

stead of selecting a specific CPU. STEP 7 creates an

unspecified CPU.

After creating the unspecified CPU, you can upload the hard-

ware configuration for the online CPU.

• From the program editor, you select the "Hardware

detection" command from the "Online" menu.

• From the device configuration editor, you select the option

for detecting the configuration of the connected device

After you select the CPU from the online dialog, STEP 7 uploads the hardware configuration

from the CPU, including any modules (SM, SB, or CM). The IP address is not uploaded. You

must go to "Device configuration" to manually configure the IP address.

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11.16 Downloading in RUN mode

11.16

Downloading in RUN mode

The CPU supports "Download in RUN mode". This capability is intended to allow you to

make small changes to a user program with minimal disturbance to the process being

controlled by the program. However, implementing this capability also allows massive

program changes that could be disruptive or even dangerous.

WARNING

Risks with downloading in RUN mode

When you download changes to the CPU in RUN mode, the changes immediately affect

process operation. Changing the program in RUN mode can result in unexpected system

operation, which could cause death or serious injury to personnel, and/or damage to

equipment.

Only authorized personnel who understand the effects of RUN mode changes on system

operation should perform a download in RUN mode.

The "Download in RUN mode" feature allows you to make changes to a program and

download them to your CPU without switching to STOP mode:

● You can make minor changes to your current process without having to shut down (for

example, change a parameter value).

● You can debug a program more quickly with this feature (for example, invert the logic for

a normally open or normally closed switch).

You can make the following program block and tag changes and download them in RUN

mode:

● Create, overwrite, and delete Functions (FC), Function Blocks (FB), and Tag tables.

● Create, delete, and overwrite Data Blocks (DB) and instance data blocks for Function

Blocks (FB). You can add to DB structures and download them in RUN mode. The CPU

can maintain the values of existing block tags and initialize the new data block tags to

their initial values, or the CPU can set all data block tags to initial values, depending on

your configuration settings. You cannot download a web server DB (control or fragment)

in RUN mode.

● Overwrite Organization Blocks (OB); however, you cannot create or delete OBs.

You can download a maximum number of twenty blocks in RUN mode at one time. If you

must download more than twenty blocks, you must place the CPU in STOP mode.

If you download changes to a real process (as opposed to a simulated process, which you

might do in the course of debugging a program), it is vital to think through the possible safety

consequences to machines and machine operators before you download.

Note

If the CPU is in RUN mode and program changes have been made, STEP 7 always tries to

download in RUN first. If you do not want this to happen, you must put the CPU into STOP.

If the changes made are not supported in "Download in RUN", STEP 7 prompts the user that

the CPU must go to STOP.

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11.16 Downloading in RUN mode

11.16.1

Changing your program in RUN mode

To change the program in RUN mode, your must first ensure that the CPU and program

meet the prerequisites, and then follow these steps:

1. To download your program in RUN mode, select one of the following methods:

- Select the "Download to device" command from the "Online" menu.

- Click the "Download to device" button in the toolbar.

- In the "Project tree", right-click "Program blocks" and select the "Download to device >

Software" command.

If the program compiles successfully, STEP 7 starts to download the program to the CPU.

2. When STEP 7 prompts you to load your program or cancel the operation, click "Load" to

download the program to the CPU.

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11.17 Tracing and recording CPU data on trigger conditions

11.17

Tracing and recording CPU data on trigger conditions

STEP 7 provides trace and logic analyzer functions with which you can configure variables

for the PLC to trace and record. You can then upload the recorded trace data to your

programming device and use STEP 7 tools to analyze, manage, and graph your data. You

use the Traces folder in the STEP 7 project tree to create and manage traces.

The following figure shows the various steps of the trace feature:

① Configure the trace in the trace editor of STEP 7. You can configure the data values to record,

the recording duration, the recording frequency, and the trigger condition.

② Transfer the trace configuration from STEP 7 to the PLC.

③ The PLC executes the program, and when the trigger condition occurs, begins recording the

trace data.

④ Transfer the recorded values from the PLC to STEP 7.

⑤ Use the tools in STEP 7 to analyze the data, display it graphically, and save it.

The maximum size of a trace is 512 Kbytes per trace.

Access to examples

See the STEP 7 information system for details about how to program a trace, how to

download the configuration, upload the trace data, and display the data in the logic analyzer.

You can find detailed examples there in the "Using online and diagnostics functions > Using

the trace and logic analyzer function" chapter.

In addition the online manual "Industry Automation SINAMICS/SIMATIC Using the trace and

logic analyzer function" (http://support.automation.siemens.com/WW/view/en/64897128 ) is

an excellent reference.

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IO-Link is easy

12.7 The SM 1278 4xIO-Link Master

12.7

The SM 1278 4xIO-Link Master

The SM 1278 4xIO-Link Master is a 4-port module that functions as both a signal module

and a communication module. Each port can operate in the IO-Link mode, single 24 VDC

digital input or 24 VDC digital output. You can connect up to four IO-Link devices (3-wire

connection) or four standard actuators or standard encoders.

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IO-Link is easy

12.7 The SM 1278 4xIO-Link Master

SM 1278 4xIO-Link Master block diagram

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IO-Link is easy

12.7 The SM 1278 4xIO-Link Master

Connection examples

The following illustration shows the configuration for IO-Link operating mode (3-wire and

5-wire), where n = port number:

The following illustration shows the configuration for DI operating mode (2-wire and 3-wire),

where n = port number:

The following illustration shows the configuration for DQ operating mode (2-wire and 3-wire),

where n = port number:

Detailed information on using and configuring the SM 1278 4xIO-Link Master

For detailed information on the SM 1278 4xIO-Link Master, including diagrams, connection,

parameterization, diagnostic alarms and more, refer to the S7-1200 Programmable

Controller System Manual.

359

Technical specifications

A.1 General technical specifications

cULus approval

Underwriters Laboratories Inc. complying with:

● Underwriters Laboratories, Inc.: UL 508 Listed (Industrial Control Equipment)

● Canadian Standards Association: CSA C22.2 Number 142 (Process Control Equipment)

Note

The SIMATIC S7-1200 series meets the CSA standard.

The cULus logo indicates that the S7-1200 has been examined and certified by

Underwriters Laboratories (UL) to standards UL 508 and CSA 22.2 No. 142.

FM approval

Factory Mutual Research (FM)

Approval Standard Class Number 3600 and 3611

Approved for use in:

Class I, Division 2, Gas Group A, B, C, D, Temperature Class T3C Ta = 60 °C

Class I, Zone 2, IIC, Temperature Class T3 Ta = 60 °C

Canadian Class I, Zone 2 Installation per CEC 18-150

IMPORTANT EXCEPTION: See Technical Specifications for the number of inputs or outputs

allowed on simultaneously. Some models are de-rated for Ta = 60 °C.

WARNING

Substitution of components can impair the suitability for Class I, Division 2 and Zone 2.

Repair of units should only be performed by an authorized Siemens Service Center.

IECEx approval

EN 60079-0: Explosive Atmospheres - General Requirements

EN60079-15: Electrical Apparatus for Potentially Explosive Atmospheres;

Type of protection ‘nA’

IECEX FMG14.0012X

Ex nA IIC Tx Gc

IECEx rating information may appear on the product with the FM Hazardous Location

information.

Only products marked with an IECEx rating are approved. Consult your local Siemens

representative if you need additional information related to the latest listing of exact

approvals by part number.

Relay models are not included in IECEx approvals.

Refer to specific product marking for temperature rating.

Install modules in a suitable enclosure providing a minimum degree of protection of IP54

according to IEC 60079-15.

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