Siemens SIMATIC MV420, Operating Instructions Manual

Page: 333 / 424

Process interfacing via an automation system (PLC, PC)
10.9 Sample programs
SIMATIC MV420 / SIMATIC MV440
Operating Instructions, 04/2013, A5E02371045-06
331
Adding program change
Specify the number of the required program in memory byte MB200. The program change
runs automatically. The correct order of the commands is adhered to. The FB changes to the
program specified at PARAM1.
CAUTION
Avoiding undefined plant states
To avoid undefined plant states, you should only change programs when the plant is in
manual mode or is not in operation.
Startup OB OB100
In OB100, you set the RESET input of FB79 to initialize the FB. This input is reset again by
calling FB79.
Bits of the control and status bytes used
The following control and status bits need to be processed in your program in addition to the
FB79 call:
Bit no. in Corresponds to
signal Function
Q x.6 Control byte TRG Processing starts on a positive edge.
Q x.7 Control byte RES Reset sensor error
I x.0 Status byte IN_OP 0: error or startup,
1: Sensor is functional
I x.2 Status byte RDY 1: Sensor is in RUN, in other words ready to process
codes.
You can use this signal to enable the feed of work
pieces.