Siemens Sinamics G120P Operating Instructions Manual page 268

Operation
6.9 Communication over CANopen
● Acyclic asynchronous (values: 254, 255)
– TPDO when a process data has changed in the telegram.
– The controller accepts the RPDO immediately.
Inhibit time
The inhibit time defines the minimum interval between two transmissions.
Synchronous data transmission
A periodic synchronization object (SYNC object) ensures that the devices on the CANopen
bus remain synchronized during transmission.
Each PDO transferred as synchronization object must include a "transmission type" 1 ... n:
● Transmission type 1: PDO in each SYNC cycle
● Transmission type n: PDO in every n-th SYNC cycle
The following diagram shows the principle of synchronous and asynchronous transmission:
Figure 6-25
For synchronous TPDOs, the transmission mode also identifies the transmission rate as a
factor of the SYNC object transmission intervals.
The CAN controller transfers data from synchronous RPDOs that it received after a SYNC
signal only after the next SYNC signal to the inverter.
Note
The SYNC signal synchronizes only the communication on the CANopen bus and not
functions in the inverter, e.g. the clock times of the speed control.
268
Principle of synchronous and asynchronous transmission
Inverter cabinet units
Operating Instructions, 12/2014, A5E32923362A