Mitsubishi Q Series Start/Stop/Latch Clear

Hi
My customer has a system that has been running for nearly 7 years. He did somthing strange with it and has managed to set an M coil in the PLC. I have looked at the program in my office and there is no Reset coil, and there does not appear to be a reset from the HMI as far as I can tell.

Does the reset / latch clear switch reset the SET M coils?

Thanks

not really...

on bigger PLCS(A,QnA,Q):
M coils get reset by powering PLC down
there are two kins of Latch areas that can be set in the parameters (only applies to retentive memory,
M is not one of them).
one of them is cleared when you use the mentioned switch

on smaller PLCs (FX):
some of the M coils are retentive.

Thanks, I looked in the Q manual after posting this and it said that you could only clear the latch area using GX Developer but thanks for replying.