GX Developer Connection Issue

[MrLupusJones]

Well, I've decided to start a new project, and like all projects, it has already gone horribly wrong.

I purchased a PLC device (supposedly a FX1N-20MR) and the included GX Developer version 8 software.

After many a youtube and google, I have connected to it and wrote a simple ladder logic to it. My issue comes up when I go to "Monitor (write mode)" to try and force on bits to test the logic. On all the videos I see, the bit will light up blue, timers will start counting, etc. My software shows nothing when forcing bits on. No highlights in blue or timer function. The mini window shows when I change the state on the board from RUN to STOP and vice versa, so I'm reasonably sure it's communicating to the device.

Any ideas why I don't get the cool highlights for function testing?

 

[Ron S]

When you say 'bits, do you mean inputs (X0 etc) Real inputs can't be forced on that model
M bits can though.

 

[lfe]

If those bits are switched in your program, they will not change with your forcing.

Try with a M or a D register that is not in your program