Siemens MICROMASTER 420 Operating Instructions Manual page 46

Data transfer using CANopen
Read PDO service
The read PDO service is an acknowledged service. One or several PDO
consumers send a Remote Transmission Request (RTR) message to the network.
After it has received the RTR message, the PDO producer sends the requested
PDO.
This service is used for RTR queries. Using this service, actual values can be
interrogated independently of the selected cycle time.
PDO Producer
Indication
Response
Fig. 3-12
PDO identifier
It is recommended that an identifier is allocated to the PDOs in the CANopen
profile for the first four transmit and receive PDOs. However, this can always be
changed by writing into the appropriate communication objects. In Micromaster 440
the COBIDs are pre-set as follows:
Receive PDOs
Transmit PDOs
46
Remote transmit request
0
Read PDO service
1. 200H + Node ID
5. 300H + Node ID
(corresponds to the pre-setting [default] for 2. after
DS301, however, the second RPDO does not exist for
the Micromaster, this is the reason that COBID was
assigned here for the next existing PDO)
6. 400H + Node ID
(corresponds to the pre-setting for 3. after DS301)
1. 180H + Node ID
5. 280H + Node ID
(corresponds to the pre-setting [default] for 2. after
DS301. However, the second TPDO does not exist for
the Micromaster; this is the reason that the COBID was
assigned here for the next existing PDO)
6. 380H + Node ID
(corresponds to the pre-setting [default] for 3. after
DS301)
Read PDO
L = 0 ... 8
Process Data
CANopen Option Module
Issue 01/05
PDO Consumer
Request
Confirmation
Operating Instructions
6SE6400-5BC00-0BP0