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Process interfacing via an automation system (PLC, PC)
10.4 Control with FB79
SIMATIC MV420 / SIMATIC MV440
Operating Instructions, 04/2013, A5E02371045-06
287
Sequence when changing a program (COMMAND = W#16#0001)
If the reader is currently executing a read job, follow these steps:
1.
Call FB79 with COMMAND=W#16#0000. This cancels the output of the result string (job
W#16#0081).
2.
Make a program change by calling FB79 with COMMAND=W#16#0001 and PARAM=
new program number. When the job is triggered, the DONE and ERROR parameters
change to the value FALSE. The ACTIVE parameter has the value TRUE. The block
changes the program selected on the reader to the value at the PARAM1 parameter. It
then queries the program now selected on the reader and outputs this program at the
CODE_OUT parameter. If the program now selected matches the program specified at
the PARAM1 parameter, the ACTIVE parameter will have the value FALSE and the
DONE parameter the value TRUE. If the program now selected does not match the
program specified at the PARAM1 parameter, the ACTIVE parameter will have the value
FALSE and the ERROR parameter the value TRUE. The ERRCODE parameter contains
an appropriate error message. The system also checks whether the program change is
being blocked by a "Service" or "User1" user logged on to the user interface who has
taken control of the reader, and whether the newly selected program has been saved. If
an error is detected, the ACTIVE parameter has the value FALSE and the ERROR
parameter has the value TRUE. The ERRCODE parameter contains an appropriate error
message.
3.
Call FB79 again cyclically with COMMAND=W#16#0081.
If you attempt to cancel a current change program job, the ERRCODE parameter will change
to DW#16#00000002; however, processing for the job will be completed.
Note
•
When there is a program change, the reader changes to STOP for at least 150 ms (refer
to selecting modes "Select program"). In isolated cases, a program change can take up to
15 s.
•
If you specify the value 0 in the PARAM1 parameter, the previously selected program will
be retained.
•
The value of PARAM1 must not be changed before the job is completed.
Summary of Contents for SIMATIC MV420
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