GE Fanuc 90-30

[GMc]

Good Morning,

I have a problem that I hope some of you GE gurus can help me with.

I have a GE Fanuc 90-30, CPU 331 and some spare input, output and analog cards from a incinerator that we tore out at work. It happens to be the PLC make and model that we use on our generators. In trying to get more familiar with the GE Fanuc I thought I would set up a test station with the spare parts to play around with.

The software we use for our generators is the logicmaster 90-30 v9.05. In trying to use the same software with the test station, I get (S37) No Communication with PLC. Next I went into the Comm Config Utility.. and you all probably guessed it, this is what I seen

Device Names

CimplicityControlEthernet
CimplicityControlSerial
Default
LM90_DEFAULT
testplc

So the big question is how does one go back to communicating with Logicmaster 90-30
software? I do not need any of the logic or information on the plc. I am currently using
WIN2k.

Thanks in advance,
Gary

[Steve Bailey]

Do any of your computers with LM90 communicate with this reclaimed PLC? Does the computer that you're using to try to talk to the reclaimed PLC communicate with other 90-30s?

I'm trying to figure out if the problem is in the computer or the PLC.

One thing you can do to restore the PLC to its out-of-the-box condition is to remove the CPU module from the rack and let it sit overnight. That will clear the memory and restore the port to 19200 kBaud, 8 data bits, Odd parity. If you do a new installation of LM90 software, it will default to the same port settings.

On the PC side, it's possible that some other application is not relinquishing the COM port. Another possibility is that if somebody has set up your LM90 to communicate via ethernet, you'll need to change the settings to go back to serial communications.

The answers to the questions I posed at the beginning will help us decide which course of action you need to follow.

[GMc]

Steve,

I will say it's not the computer. The computer connects fine with our
GE's on our generators which is set up for serial.

What is strange is that it has been unplugged from the backplane for 2 weeks now..

I looked further into one of your other post about clearing memory. In a manual I was reading it mentioned MEM CLR pads located on the back of the 331 CPU. I don't see any such thing.

THe model I have is IC693CPU331S

Thanks,
Gary

[Steve Bailey]

The RS232/422 converter that you use to communicate with the PLC gets its power from the PLC. It's possible that you're not getting power to it. You should see 5 VDC between pins 5 and 7 on the 15 pin serial port.

There are no markings on the capacitor that you short out. It's shaped like a hockey puck and located on the same board that has the plug that attaches the module to the backplane. You have to take the circuit boards out of the plastic case to get at it.

[GMc]

Steve,

I thought I read somewhere that if you load a program to the plc using cimplicity or versa pro that you will no longer be able to communicate with the plc using logicmaster. So I was just assuming after seeing the info from the comm utility that this was the one and only reason I'm not able to communicate with it.

Thanks,
Gary

[Steve Bailey]

Logicmaster can't view or edit a program created with VersaPro or ME, but it can still communicate with the CPU and overwrite the VP or ME program with a LM90 program.

[DesertDog]

Newer GE CPU's have either 2 gold edge tabs for reset or 2 pins labeled reset. All that actually happens is the big capacitor is shorted to drain all the backup power. On the OLD CPU's once the board is removed from the case this capacitor can be easily seen ant the pins from it poking out the other side of the board can be shorted.

[GMc]

Steve,

I will try again and see if I can download a program and overwrite what ever is in the PLC.

DesertDog,

I must have the older one then because I don't have the 2 pins on the back of the cpu. I tried to get the board out but the 2 black tabs that hold the board in are going to break off if I keep trying..

If all else fails, I will wait till Monday when I can get my hands on the Hand Held Programmer. I read where you can use that to clear the memory..

Thanks Steve and DesertDog..

I appreciate the info

Gary

[Steve Bailey]

Use a small screwdriver to pry those black tabs out of the way. There are four of them, two on each side of the plastic case. The CPU module has two circuit boards. Each pair of tabs retains one circuit board.

If the CPU module has been removed from the backplane for two weeks as you said, you don't have to discharge the capacitor. The battery that retains the RAM memory is physically located on the power supply module, so when you take the CPU out of the backplane, the only thing retaining the memory is the capacitor. It's not good for more than a few hours. Of course, if this CPU has been fitted with non-volatile memory, that's a different story...

Did you check for the presence of 5 VDC on the serial port to power the converter? What LEDs on the power supply are lit when you power the thing up?

[GMc]

Steve,

The laptop I was using here at home is identicle to the one I use at work on our generators except I don't have as much memory on this one at home and I only have ver. 7.02 loaded at home. It just won't communicate.

So... I loaded ver. 9.05 on my desktop and it works fine.. The CPU must be fitted with non-volatile memory because the program is still there..

I thank you as DesertDog for the responses.. I surely appreciate the help.

Gary

[Steve Bailey]

At LM90 version 7.02, you might be having operating system issues. That version dates back to around 1997. It might not be loading the serial port communications driver properly. Load v 9.05 onto your home laptop and I expect your problems will disappear.

[GMc]

Ok Steve, I will try and let you know..

Thanks,
Gary

[GMc]

Steve,

Now that I'm able to communicate with the PLC I've been trying to download a program but the program name doesn't change in the PLC. The program name in the PLC is HHP and the the program I downloaded is P166325. What the heck am I doing wrong?? This particular PLC (331) does not have a EPROM or a EEPROM. Thanks

Gary

[GMc]

I'm only guessing but I think clearing the memory with the Hand Held Programmer caused the program name to be HHP. I tried to download my program but the name in the plc is still HHP.. I surely don't know what I'm doing wrong.. frustrated to say the least..

Gary

[GMc]

Okay, maybe I was too tired or too frustrated yesterday. I tried it again this morning and everything seems to be ok.. Here is what I did..

I cleared the memory again with the Hand Held, hooked up the laptop and in the cpu config, I chabged Logic/Cfg: PROM to Ram and Registers: PROM to RAM. I then downloaded the program. I shut the PLC off and when I turned it back on everything was correct.. meaning same program name as what I downloaded..

As far as the laptop Steve, it works great with the newer ver 9.05

Thanks

Gary