Monitoring Active Commands; Monitoring Mc Instructions With A "Done" Output Parameter - Siemens S7-1200 System Manual

9.3.8

Monitoring active commands

9.3.8.1

Monitoring MC instructions with a "Done" output parameter

Motion control instructions with the output parameter "Done" are started by the input
parameter "Execute" and have a defined conclusion (for example, with motion control
instruction "MC_Home": Homing was successful). The task is complete and the axis is at a
standstill.
● The output parameter "Done" indicates the value TRUE, if the task has been successfully
● The output parameters "Busy", "CommandAborted", and "Error" signal that the task is still
The tasks of the following motion control instructions have a defined conclusion:
● MC_Reset
● MC_Home
● MC_Halt
● MC_MoveAbsolute
● MC_MoveRelative
The behavior of the status bits is presented below for various example situations.
● The first example shows the behavior of the axis for a completed task. If the motion
● The second example shows the behavior of the axis for an aborted task. If the motion
● The third example shows the behavior of the axis if an error occurs. If an error occurs
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
completed.
being processed, has been aborted or an error is pending. The motion control instruction
"MC_Reset" cannot be aborted and thus has no "CommandAborted" output parameter.
– During processing of the motion control task, the output parameter "Busy" indicates
the value TRUE. If the task has been completed, aborted, or stopped by an error, the
output parameter "Busy" changes its value to FALSE. This change occurs regardless
of the signal at input parameter "Execute".
– Output parameters "Done", "CommandAborted", and "Error" indicate the value TRUE
for at least one cycle. These status messages are latched while input parameter
"Execute" is set to TRUE.
control task has been completely executed by the time of its conclusion, this is indicated
by the value TRUE in output parameter "Done". The signal status of input parameter
"Execute" influences the display duration in the output parameter "Done".
control task is aborted during execution, this is indicated by the value TRUE in output
parameter "CommandAborted". The signal status of the input parameter "Execute"
influences the display duration in the output parameter "CommandAborted".
during execution of the motion control task, this is indicated by the value TRUE in the
output parameter "Error". The signal status of the input parameter "Execute" influences
the display duration in the output parameter "Error".
Technology instructions
9.3 Motion control
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