User Manual

Motion control is easy
10.5 Motion control instructions
Easy Book
Manual, 03/2014, A5E02486774-AF
217
10.5
Motion control instructions
10.5.1
MC instruction overview
The motion control instructions use an associated technology data block and the dedicated
PTO (pulse train outputs) of the CPU to control the motion on an axis.
● MC_Power (Page 217) enables and disables a motion control axis.
● MC_Reset (Page 221) resets all motion control errors. All motion control errors that can
be acknowledged are acknowledged.
● MC_Home (Page 222) establishes the relationship between the axis control program and
the axis mechanical positioning system.
● MC_Halt (Page 224) cancels all motion processes and causes the axis motion to stop.
The stop position is not defined.
● MC_MoveAbsolute (Page 226) starts motion to an absolute position. The job ends when
the target position is reached.
● MC_MoveRelative (Page 228) starts a positioning motion relative to the start position.
● MC_MoveVelocity (Page 230) causes the axis to travel with the specified speed.
● MC_MoveJog (Page 233) executes jog mode for testing and startup purposes.
● MC_CommandTable (Page 235) runs axis commands as a movement sequence.
● MC_ChangeDynamic (Page 237) changes Dynamics settings for the axis.
● MC_WriteParam (Page 239) writes a select number of parameters to change the
functionality of the axis from the user program.
● MC_ReadParam (Page 241) reads a select number of parameters that indicate the
current position, velocity, and so forth of the axis defined in the Axis input.
CPU firmware levels
If you have an S7-1200 CPU with V4.0 firmware, select the V4.0 version of each motion
instruction.
If you have an S7-1200 CPU with V3.0 or earlier firmware, select the applicable V3.0, V2.0,
or V1.0 version of each motion instruction.
10.5.2
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.