8400 StateLine C | Reference manual
System bus "CAN on board"
Process data transfer
454 L Firmware ≤ 11.00 - DMS 8.0 EN - 10/2011
10.8.4 PDO synchronisation via sync telegram
During cyclic transmission, one or more PDOs are transmitted/received in fixed time
intervals. An additional specific telegram, the so-called sync telegram, is used for
synchronising cyclic process data.
The sync telegram is the trigger point for the transmission of process data from the
slaves to the master and for the acceptance of process data from the master in 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 selected transmission
type.Transmission type
( 451)
Basic workflow
[10-6] Sync telegram
A. After the sync telegram has been received, the slaves transmit the synchronous process
data to the master (TPDOs). The master reads them as process input data.
B. When the transmission process is completed, the slaves receive (RPDOs) the process
output data (of the master).
– All other telegrams (e.g. parameters or event-controlled process data) are accepted
acyclically by the slaves after the transmission is completed.
–Illustration [10-6]
does not include acyclic data. However, they need to be considered
when dimensioning the cycle time.
C. The data are accepted in the slave with the next sync telegram if the Rx mode is set to
1 ... 240. If the Rx mode is 254 or 255, the data are accepted in the next device cycle,
irrespective of the sync telegram.
Short overview: Parameters for the synchronisation via sync telegram
Related topics:
Synchronisation of the internal time base
( 506)
n Sync cycle time (C01121)
To Next Page
Loading...
