a FX2N cant go in RUN mode anymore

[sebosebi]

Hello, i have a FX2N 32MR on a wind turbine, and i have a unusual problem. I cant go in RUN mode in no ways, but the PLC have no errors, no blinking on the front panels, M8060-M8069 debugged all "0". I tried everything, forced M8035-M8036, toggled M8037. The only thing i cant do until now is to shut off the PLC because it is under a battery pack. Obviously i can communicate with it normally, via Bluetooth in HMI pass through. I can download and upload programs and debug. For example forcing M8037 ON dont put OFF M8035 M8036. Did someone ever meet such situation? Do you think that PLC is gone? Is there something i could try in low level registers, before go on the turbine and try other solutions (shut down or replacement)? Thanks

[sebosebi]

Other information is that scan time of the program is always 0ms instead of 6ms it should be....

[kaare_t]

Probably a stupid question, but is the RUN/STOP switch in "RUN" position??

[sebosebi]

I dont exactly know this, but i dont think its relevant, because on FX2N normally we can remotely RUN/STOP with switch in either position

[plcdp]

Is that correct? You can remotely go into run mode even if the physical switch on the PLC is positioned to stop??? Edited March 19, 2012 by plcdp

[sebosebi]

Absolutely yes. Try it. If you go in RUN mode remotely with switch in STOP mode is a way to exclude switch, the only way to put again in STOP is remotely or by M8037.

[JRoss]

Was this a working machine that suddenly started faulting, or is it a new machine?

[sebosebi]

Working machine, it went ok... the problem appeared when we made an upload of a program that we had interrupted (not completed)..... after this it never goes to RUN mode, but we havent errors and then we put inside a correct software... it only not goes in RUN mode

[kaare_t]

I'm pretty syre plcdp is correct: If the PLC switch is in RUN mode you can remotely run/stop the PLC. However if the PLC switch is in STOP mode you cannot force it to run from the software. In addition, if you have a corrupted upload/download, format/clear the PLC memory, then download the correct project and power off/on the PLC again.

[Crossbow]

I am fairly certain you CANNOT start it remotely if the switch is not in RUN.

[sebosebi]

Im sorry, but im SURE that i CAN put in RUN remotely if im in STOP by switch... anyway, before i have this problem i put in RUN almost 2 times before i cant put in STOP anymore so that isnt the reason why i have the problem

[sebosebi]

i meant "... before i cant put in RUN anymore..."

[Cetronic]

Well folks I have just physicall checked this with a FX1N and 2N and it is indeed possible to put the CPU in Run mode with Switch in the Stop Position. However Cycling the power defaults to the switch Position Default but can restarted. I assume this would mean that a Program Cycle/Error would default to the same process. Dont know why you would want the Run Stop in the continuous Stop Position.

[sebosebi]

A reason could be if i want that noone can stop with the switch.... Anyway my problem isnt that.... my problem is that i cant go in RUN anymore and that not depends from the position of the switch.... have someone any hints about something i can do before go in the nacelle and shut off the PLC?

[Cetronic]

Yup Site visit seems the Go and good luck with that. I am sure the forum will be interested in the resolution.

[kaare_t]

Try to erase the memory WITHOUT downloading the program, then try to set the PLC in run again.

[sebosebi]

kaare_t i did it but without results.... the strange is that i have always a 0ms scan and normally if i clear memory i have a 2ms scan and if i put my program i have 6ms....

[kaare_t]

The reason why you have 0ms scan time is because the PLC is in STOP mode.... I'm starting to think it's a hardware fault. When you clear the PLC memory, the CPU should go into RUN mode without problems since no logic will prevent it from going into RUN.

[sebosebi]

if you check with MELSOFT you can see that also in a PLC in STOP mode you have >0ms scan.... anyway i also think its a deep hardware fault.... tomorrow we will put off DC and start again ill let uou know if it will revive

[WKla]

Hello, I have two observation to make: 1. In some cases if the program downloaded in the PLC is faulty, the remote RUN is not working. Only if you cycle the local switch on STOP and RUN again the PLC will enter in fault (ERROR led flashes) and then the errors from the PLC could be read. 2. We had the same situation with an FX1N PLC that is just not switching in RUN mode. Tried to clear all memory and then put the program, not working. I used the local switch to change in to RUN and STOP. I think in this case could be an hardware fault.