Festo CMMT-ST-SW, Original Instructions Manual

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NOTICE!
The request of the write command (download … request) must not use an object that is mapped in the
"receive PDO mapping (0x1600)" object. The alternating transmission of process data objects PDO
and service data objects SDO would overwrite the data of the object (Value) in an undefined time
sequence.
11.8.1.2 SDO read command (SDO upload/upload SDO)
Via the SDO read command (SDO read command) the controller (Controller) can acyclically access the
CoE object directory CoE OD in the CMMT to read the data of an object (Value). After processing the
read command, the CMMT sends a response (Answer) to the controller with the requested data.
Controller CMMT
SDO upload/Upload SDO ... request
(SDO read command)
Request
Answer
SDO upload/Upload SDO ... response
CoE OD
Object
Value
Fig. 116 Read access to object data
The SDO service supports the following SDO write commands:
SDO service Description
SDO upload expedited request Read command request for 1
…
4 bytes user data
SDO upload expedited response Read command response with 1
…
4 bytes user data
SDO upload normal request Read command request for 5
…
1,406 bytes user data
SDO upload normal response Read command response with 5
…
1,406 bytes user data
Upload SDO segmented request Read command request for 1,407
…
n bytes user data
Upload SDO segmented response Read command response 1,407
…
n bytes user data
Tab. 472 Supported SDO read commands
NOTICE!
The controller must not send the next request (request) until the response to the read command
(upload … response) has been received by the controller.
11.8.1.3 SDO error message (Abort SDO transfer request)
In the case of an error (SDO Error) when reading, writing or transmitting the SDO the CMMT responds
with a SDO error message (Abort SDO transfer request). The cause of error is transmitted as an abort
code (Abort codes) in the data (Data) of the error message to the controller (Controller).
EtherCAT
538 Festo — CMMT-ST-SW — 2019-02