Fx2n Which is hold bit for power and on

[Bossp]

Hi All, I new to programing in Mitsubishi fx2n plc,i want to know which memory (M) bit can hold after switch off and on the plc. Thanks, Bossp Edited May 15, 2014 by Bossp

[kaare_t]

By default, M384-M311 are latched. However you can change this in the PLC Parameters to whatever you want between M0-M1023.

[Bossp]

Thanks for your reply my friend,can you please explain me how we can change the plc parameter. Thanks Bossp

[kaare_t]

No problem, of course we can assist you. However we would need to know which software you are using. As a general note; Go into "PLC Parameter" on the left side (project tree), go into "Device" tab. Here you will find all the "Latch Start" and "Latch End" parameters for the different devices available, and you can tune them to whatever you want within the individual ranges.

[Bossp]

I am using the softwear GX Developer Verson 8.85P.It's there 500 t0 1023 latching bits but i have used M504 it's not getting hold after switch off and on. Thanks Bossp

[Goody]

Then it might be being purposely reset on power up by something like --M8002-------ZRST M500 M550. Just a guess of course but try checking if M8002 is being used anywhere.

[Bossp]

hi friends,It not Reset By M8002 Also.

[kaare_t]

It's not M8002 that resets the bit. It may be any RST/Reset/MOV K0 instruction that resets bit(s). In essence you need to go through the program and check for instructions that may reset the bit(s). Maybe this is a sequence program that automatically resets bit(s) during startup, or the end of a sequence or similar...

[Bossp]

Yes friend it was used,in this case which bit can recomanded