Data transfer using CANopen Issue 01/05
CANopen Option Module Operating Instructions
46 6SE6400-5BC00-0BP0
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.
Response
Process Data
0
Confirmation
L = 0 ... 8
Read PDO
Request
Remote transmit request
Indication
PDO Producer PDO Consumer
Fig. 3-12 Read PDO service
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 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)
Transmit PDOs 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)
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