4 synchronisation of pdos via sync telegram, Synchronisation of pdos via sync telegram, E94aycca communication manual (canopen®) – Lenze E94AYCCA User Manual

Page 50

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E94AYCCA communication manual (CANopen®)

Process data transfer

Synchronisation of PDOs via sync telegram

50

L

EDS94AYCCA EN 5.0 - 06/2012

8.4

Synchronisation of PDOs via sync telegram

In case of cyclic transmission, one or several PDOs are transmitted or received at fixed time

intervals. For synchronising the cyclic process data, an additional special telegram, the sync

telegram, is used.

 The sync telegram is the trigger point for the transmission of process data from the

frequency inverters to the master and for the acceptance of process data from the

master by the slaves.

 For sync-controlled process data processing, the sync telegram must be generated

accordingly.

 The response to a sync telegram is determined by the transmission type selected.



Transmission type

( 47)

General procedure

[8-2]

Sync telegram

A. After the sync telegram has been received, the slaves send the synchronous process

data to the master (TPDOs). The master reads them as process input data.

B. When the sending process has been completed, the slaves (RPDOs) receive the process

output data (from the master).
– All other telegrams (e.g. parameters or the event-controlled process data) are

accepted acyclically by the slaves after the transmission has been completed

successfully.

– The acyclic data are not shown in figure

[8-2]

They must be considered when the

cycle time is dimensioned.

C. The data in the slave is accepted with the next sync telegram if the Rx mode is set to

1 ... 240. When the Rx mode is set to 254 or 255 the data is accepted in the next device

cycle independent of the sync telegram.

1 Sync cycle time (

C01121

)

Œ

SYNC

SYNC

0

1

2

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