Siemens SIMATIC FM 353, Manual

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Programming the Technological Functions
6-33
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
As soon as a Write request is detected (also on a signal change in the case of
single functions), it is serviced immediately upon completion of the transfer cur-
rently in progress, if any. Be sure that signals for single commands are not set
cyclically, as this could prevent other job requests from being serviced (priority).
Order/priority of Write requests:
1. Write single commands
2. Write single functions
3. Write requests.
The Write requests are serviced in the order of the Initiate signals,
which is stipulated in user data block AW-DB (from DBX38.0 to 39.7).
Order/priority of Read requests:
1. Read error code, operator/traverse errors or data errors
2. Read requests
The Read requests are serviced in the order of the Initiate signals,
which is stipulated in user data block AW-DB (from DBX42.0 to 43.6).
S Job request status
You can read the status of the job processing infrom the RETVAL instance
variable of the block and from the “Write/read job in progress” signals in user
data block AW-DB (DBX68.0 and DBX68.2). You can evaluate the status of an
individual job request by evaluating the Initiate, Ready and Error signals for that
job request.
Table 6-7 Job request status
Job request status
RETVAL
instance
variable
(integer)
Jobs in
progress
(DBX68.0
DBX68.2)
Initiate
signals
(DBB34...43)
Ready
signals
(DBB44...53)
Error
signals
(DBB54...63)
1. Job in progress 1 1 1 − −
2. Job completed without
errors
0 − − 1 −
3. Write job completed with
errors in this job
− 1 − − 1 1
4. Write job aborted or not
executed
− 1 − − − 1
5. Read job aborted − 2 − − − 1
6. Write and Read aborted
or not executed (in case
of simultaneous job re-
quests)
− 3 − − − 1
− Irrelevant for error evaluation