Lenze 931M-931W - Manual (Page 44)

CANopen communication
Sync telegram
Telegram structure
5
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44 KHB 13.0003-EN 2.0
5.4 Sync telegram
It is possible to synchronise several controllers of a plant with each other. For this, the
master usually periodically sends synchronisation messages. All controllers connected
receive these messages and use them for PDO processing.
5.4.1 Telegram structure
11 bits 4 bits
Identifier
Data
length
The identifier on which the drive controller receives the sync telegram is permanently set
to 080
h
. The data length is 0.
5.4.2 Synchronisation of the process data
The sync telegram is the trigger point for data acceptance in the drive controller and it
starts the sending process of the drive controller. Cyclic process data processing requires
an appropriate generation of the sync telegram.
1.
PDO1-TX PDO1-RX
2. 3. 4.
 
epm-t111
Fig. 3 Synchronisation of cyclic process data by means of a sync telegram (without consideration of
asynchronous data)
c Sync telegram
Transmission sequence
1. After the sync telegram has been received, the cyclic process data are send from the
drive controllers to the master. The data is read by the master as process input data.
2. When the sending process is completed, the process output data (of the master) is
received by the drive controllers.
3. The data is accepted by the drive controllers with the next sync telegram.
4. All other telegrams (e.g. for parameters or event-controlled process data) are
accepted asynchronously by the drive controllers after the transmission has been
completed.