Siemens SIMATIC MV420, Operating Instructions Manual

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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
289
Sequence when outputting the status of the reader (COMMAND = W#16#0004)
Based on the status byte of the reader, the block recognizes the current status and outputs
this in the STATE parameter:
●
If the IN_OP bit is not set, status 3 (ERROR) is output.
● If the IN_OP but not the RDY bit is set, status 2 (STOP) is output.
● If the IN_OP but not the RDY bit are set, status 1 (RUN) is output.
The DONE parameter then has the value TRUE and ACTIVE the value FALSE.
Note
Since the job completes in one CPU cycle, no edge change can be detected at the ACTIVE
parameter. If the DONE parameter already has the value TRUE from a previous job, it is also
not possible to detect an edge change.
Sequence when resetting the DISA bit (COMMAND = W#16#0005)
The block resets the DISA bit in the control byte of the reader. The DONE parameter then
has the value TRUE and ACTIVE the value FALSE.
Note
Since the job completes in one CPU cycle, no edge change can be detected at the ACTIVE
parameter. If the DONE parameter already has the value TRUE from a previous job, it is also
not possible to detect an edge change.