PLC GE Farnuc 90 30 Series

Problem:- Input signals exists at all input modules,but there is no output at the output modules,all fuses are good. What are the possible causes????

It is not in RUN Mode, either through a fault or programmer forgetting to after loading the program.

Thanks to you Buddy.Do you have any suggestion how to put this in run Mode? As I have never came across this model of PLC. Should I get a programmer to put it in run mode?

It depends, if it is a fault then powering down then back up it may come back online.

I am now assuming this is in a machine that was working?

If so then I expect you may need someone with the software and is familiar with it to look at it. It is also possible something has either corrupted or cleared the memory too, like a dead battery, if power is turned off and battery bad memory is cleared.

Usually the lights, Power, OK, RUN, and BATT will give you a clue. If Power is not On and you know it has power to it, then the power supply may be bad. The other lights will offer other clues, tell whether each is on, off, or flashing.

Once again,thanks.I will do as you suggest.

What model CPU? Did it ever work properly?

There are four LEDs on the power supply module. The top three, labeled "PWR", "OK", and "RUN" are normally lit. The "BATT" LED should be off. If it is on it means the backup battery voltage is too low to retain the RAM memory. In that case you may no longer have a program.

The "PWR" LED indicates that there is power to the PLC. The "OK" LED blinks for a few seconds during initialization then stays on steady. The "RUN" LED is lit when the PLC is running its program.

If the "RUN" LED is not on, that would explain what you're seeing. The LEDs on the input module are on the field side wiring, so they indicate current flow at the terminals.

The default configuration of that model PLC is that when you turn on power it comes up doing the same thing it was doing when it powered down. If it was running when you turned power off, it will start running when you re-apply power. If it was stopped when powered down, it will power up stopped. If it stopped running because of a fault, you will need to connect the programming software to clear the fault before you will be able to get it running again.

AHHH the old GM Fanuc What a piece of work!!!!!!! I had a number of problems with this one! what kind of controler?

OLD and problems? The 90-30 is still around and as good as many. I just kept the thread at top etc., waiting for Steve or Russ to show up.