VIPA System 200V IM Series, Manual

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Chapter 5 CANopen
Manual VIPA System 200V
5-56 HB97E - IM - Rev. 06/29
If the Consumer-Producer model of the CANopen PDOs shall be used for
direct data transfer between nodes (without master), you have to adjust the
identifier distribution accordingly, so that the TxPDO identifier of the
producer is identical with the RxPDO identifier of the consumer:
This procedure is called PDO linking. this enables for example the simple
installation of electronic gearing where several slave axis are listening to
the actual value in TxPDO of the master axis.
CANopen supports the following possibilities for the process data transfer:
•
Event triggered
•
Polled
•
Synchronized
The "event" is the alteration of an input value, the data is send immediately
after value change. The event control makes the best use of the bus width
for not the whole process image is send but only the changed values. At
the same time, a short reaction time is achieved, because there is no need
to wait for a master request.
PDOs may also be polled via data request telegrams (remote frames) to
give you the opportunity to e.g. send the input process image of event
triggered inputs to the bus without input change for example a monitoring
or diagnosis device included during runtime.
The VIPA CANopen bus couplers support the query of PDOs via remote
frames - for this can, due to the hardware, not be granted for all CANopen
devices, this communication type is only partially recommended.
It is not only convenient for drive applications to synchronize the input
information request and the output setting. For this purpose, CANopen
provides the SYNC object, a CAN telegram with high priority and no user
data which receipt is used by the synchronized nodes as trigger for reading
of the inputs res. writing of the outputs.
PDO linking
PDO Communica-
tion types
Event triggered
Polled
Synchronized