6
Device Control
150
Festo – GDCP-CMMP-M3/-M0-C-CO-EN – 1510b – English
6
Device Control
6.1
Status Diagram (State Machine)
6.1.1
Overview
The following chapter describes how the motor controller can be regulated under CANopen, that is,
how the output stage is switched on or an error is acknowledged, for example.
Under CANopen, the entire control of the motor controller is achieved through two objects: The host
can control the motor controller through the controlword, while the status of the motor controller can
be read back in the statusword object. The following terms are used to explain controller regulation:
Term
Description
Status:
(state)
The motor controller is in different statuses, depending on whether the
output stage is switched on or an error has occurred, for example. The
statuses defined under CANopen are presented in the course of the
chapter.
Example: SWITCH_ON_DISABLED
Status transition
(state transition)
Just as with the statuses, it is also defined under CANopen how to go
from one status to another (e.g. to acknowledge an error). Status
transitions are triggered by the host by setting bits in the controlword or
internally through the motor controller, when it recognises an error, for
example.
Command
(command)
To trigger status transitions, certain combinations of bits must be set in
the controlword. Such a combination is designated a command.
Example: Enable Operation
Status diagram
(state machine)
The statuses and status transitions together form the status diagram,
that is, the overview of all conditions and the transitions possible from
there.
Tab. 6.1
Controller regulation terms