Mitsubishi FX2N PLC - Will this subroutine run?

For some background information, I am in the process of converting a Mitsubishi FX2N to a Siemens S7-1200. I am viewing the Mitsubishi program with GX Developer Version 8.116W.

There is this subroutine in the Mitsubishi program that appears like it will never run. I think the purpose of this subroutine is to clear the status of the devices in the PLC. I have attached a picture that demonstrates what I am dealing with. Can anyone tell if the subroutine P7 will run at any point? Thanks!

For those who are not used to the Mitsubishi world or want to brush up on their Mitsubishi knowledge, below is some information regarding the devices and functions*used in my example:

M8000 - Always on bit (turns on when PLC is running and turns off when PLC is stopped).

M500 - Just some random memory bit I chose.

FEND - Indicates end of main routine program (everything below this rung is either a subroutine or interrupt routine, so it will only be processed if called from somewhere).

P7 on left side of power rail - This is a label that indicates the beginning of the subroutine called P7.

M8031 and M8032 - Special memory bits that, when set, tells the PLC to clear certain devices.

SRET - Indicates end of subroutine.

Not with the CALL P7 disabled by M500

Steve

Btw, M500 is retentive and will never go off like that

Sometimes routines like that could be used to only run a sub-routine (manually by programmer) when a PLC program is first downloaded and/or configured for its specific hardware. It may not be designed to run continuously or programmatically. In your case, because the M8031 and M8032 are Mitsubishi hardware specific you probably don't need to worry too much about converting this section.

I will do something similar with test bypass bits (bypass a prox switch for example). I'll set them up so that on the first PLC scan they will be unlatched/set off. That way once the system is powered on I can toggle them on/off whenever, knowing that if I forget to delete the bypass when the machine ships they won't be active anymore.