68 EM-ABS-01 for ACU 03/12
7.11.4 Communication relationships of the process data channels
Regardless of the process data to be transmitted, the communication relationships of
the process data channels must be defined. The connection of PDO channels is done
via the assignment of the identifiers. The identifiers of Rx-/Tx-PDO must match in
each case.
Generally, there are two possibilities:
- one Rx-PDO to one Tx-PDO (one to one)
- connect several Rx-PDO’s to one TxPDO (one to many)
This process is documented in a tabular form via a communication relationship
list.
Example:
Frequency inverter
1
Frequency inverter 2 Frequency inverter 3
PDO Identifier PDO Identifier PDO Identifier
TxPDO1 385 TxPDO1 TxPDO1
RxPDO1 RxPDO1 385 RxPDO1 385
TxPDO2 641 TxPDO2 TxPDO2 642
RxPDO2 RxPDO2 641 RxPDO2
TxPDO3 TxPDO3 TxPDO3
RxPDO3 RxPDO3 642 RxPDO3
Atten-
tion:
All the TxPDOs used must have different identifiers !!!
The Identifier must be clear in the system bus network.
Frequency inverter 2
PDO2
Rx Tx
385 641
PDO1
Rx
Tx
PDO3
Rx Tx
Frequency inverter 1
PDO2
Rx
Tx
385
641
PDO1
Rx
Tx
PDO3
Rx
Tx
Frequency inverter 3
PDO2
Rx Tx
385642
PDO1
Rx
Tx
PDO3
Rx Tx
642