RUN/STOP switchΒΆ
The AC500-CPUs PM554 and PM564 contain a RUN/STOP switch which can be set with a small screwdriver. In the RUN position, the program loaded in the CPU will be executed and in the STOP position it will be stopped.
When COM1 and COM2 are not in online access mode, the user program can only be changed, uploaded and downloaded if the RUN/STOP switch is in STOP position.