axes group states (state diagram)

The state diagram displayed in the following defines the behaviour of an axes group. It shows which commands are valid in which states and which state changes they cause.

  • The axes group is always in one of the defined axes group states.
  • The arrows between the axes group states mark possible state changes (transitions). The dashed arrows mark automatic state changes after executing a command as well as error-dependent state changes.

State diagram (PLCopen state machine)

All function blocks for multi-axes movements

In the states, all FBs except for the mentioned are rejected with an error messages. Only MC_GroupReset in the "GroupErrorStop" state and errors occurred cause a state change to "GroupStandby" or "GroupErrorStop".

MC_GroupStop . Done = TRUE AND MC_GroupStop . Execute = FALSE

axes group state "GroupDisabled"

The "Group Disabled " axes group state describes the basic state after switch-on. Then, MC_GroupEnable serves to change to the next axes group state "Group Standby ".

The single real drive axes of the axes group (ACS) can only be instructed in the "GroupDisabled" state independent of each other with single axis commands (e.g. MC_MoveAbsolute , MC_Home , MC_Stop , etc.).

axes group state "GroupStandby"
  • The axes group is enabled.
  • There is no error in the axes group.
  • NO motion commands are active.
  • If required, a homing of the axes group can be carried out by means of MC_GroupHome (change to the "GroupHoming" state).
axes group state "GroupMoving"

When a motion command is executed, the "GroupMoving" axes group state is active. After a successful execution, it is automatically changed back to the "Group Standby " axes group state .

axes group state "GroupStopping"

This special axes group state is active if the axes group is braked to standstill in a controlled manner using the MC_GroupStop command.

axes group state "GroupErrorStop"

The "Group ErrorStop " axes group state has the highest priority and gets active if an error occurs in an axis. The axes group state can only be left by acknowledging the error using MC_GroupReset if the error cause has been removed.

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