GOT foced bits

[tvaughn]

I was wondering if anybody knows why that sometimes we're not able to force inputs on from our HMI's . We use either A1SH, FX2N, and some old FXON plc's and F940 or F930 GOT's. On most of these we can go to the parameters of the GOT select HPP mode/device monitor then select a bit and force on, but sometimes the bit will only come on for 1 scan then shut off. I understand that if the plc is telling the bit to shut off it will do this, but it will also do this on X bits. The manual just says something about it may not work if on a network, but none of ours is. Anyone have any ideas? Thanks in advance

[Crossbow]

Are the X bits you are trying to force real inputs on the PLC? If the real input is off, then even after you force on, it will turn back off. Forcing in Mitsu is not always stragithforward. I usually parallel some M bits in my programs to any input X bits I might want to be able to force. Then when I turn on the M bit, the OR logic in my program accomplishes the same effect as forcing the X on.

[tvaughn]

What is confusing me is that on most machines I can force on X bits. It seems as long as the program is not forcing the bit off (which you can't do to an X bit) the force function works fine, but we have just a few that don't "latch in". I have tried to compare parameter settings between a machine with the same plc/hmi that does work to one that doesn't and haven't been able to come up with anything.