Device Control - Festo CiA 402 Manual

5

Device Control

5 Device Control
5.1 Status diagram (State Machine)
5.1.1 Overview
This 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 object controlword (6040h), while the status of the motor
controller can be read back in the object statusword (6041h). The following terms are used to explain
motor controller regulation:
Term
Status:
(State)
Status transition
(State Transition)
Command
(Command)
Status diagram
(State Machine)
Tab. 5.1 Terms for motor controller regulation
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Description
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 chapter.
Example: SWITCH_ON_DISABLED
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 trans-
itions are triggered by the host by setting bits in the controlword or in-
ternally through the motor controller, when it recognises an error, for
example.
To trigger status transitions, certain combinations of bits must be set in
the controlword. Such a combination is designated a command.
Example: Enable Operation
The statuses and status transitions together form the status diagram,
that is, the overview of all conditions and the transitions possible from
there.
Festo – GDCP-CMMS/D-C-CO-EN – 1404NH – English