Lost communication with GE Fanuc (model IC200UDD120-BD)

[dawkirst]

Hello guys,

Currently I have two PLCs.

The first PLC is a GE Fanuc VersaMax PLC, model IC200UAL006-CE. I've stored a simple ladder logic program to it via VersaPro. Then I downloaded the demo version of Automated Solutions' GE SNPX ActiveX Toolkit (http://www.automatedsolutions.com/products/geserialsnpx.asp) and succeeded in using the control to read, and write values to a register in the PLC.

Then I setup my second PLC (the one mentioned in the thread title) with exactly the same ladder logic program as the first PLC and tried to read and write values to the register in the same manner I used the ActiveX control with the first PLC. Up until here all worked well.

Then I decided I would try to multidrop the two PLCs on one COM port. For this, I know you need to assign different SNP IDs for each device.

Instead of doing it via VersaPro, I decided I'll try to do it with the ActiveX control. At this time, COM 1 was connected to the second PLC. I assigned the integer 2 to the NetworkNode property of the control (which is the equivalent of the SNP ID) and I compiled my VB.NET program and it run.

I couldn't read or write values to the register, and since then, I can't talk to the PLC anymore. I've tried everything. The COM1 connection attempt just keeps on timing out.

Do you think that the ActiveX control has maybe overwritten something important? If so, what can I do to remedy this?

Thanks ahead!

 

[Steve Bailey]

I don't think that the SNPX protocol includes a command to change the SNP ID of the PLC, so I expect that the problem is in the ActiveX control. I'm not familiar with the control you're working with, but maybe you set it up so that it is trying to communicate with SNP ID 2, but the PLC is still set at whatever it was before you made the change.

Can you still communicate through VersaaPro?

 

[dawkirst]

Hey Steve,

Sorry I forgot to mention it, but no, I can't even communicate with the PLC through VersaPro anymore.

The ActiveX object property I used to change the SNP ID was myActiveXControl.NodeAdress = X, which according to the documentation "sets or returns the SNPX ID of the target device."
One thing I noticed now though, is that the property accepts a string as a datatype, while I assigned an integer to it...but surely the ActiveX control must have some sort of data validation mechanism to regulate data asignments?

 

[RussB]

On the left end of the unit, just below the RJ-45 connector are 3, 1x10 mm vents. You will see the leads of a 'super-cap' in the center one of these.
Disconnect the battery and short these leads. This will set the unit back to "like new" as far as the configuration and logic is concerned. You should be able to communicate again, then use Proficy ME to change the SNP ID. HTH

 

[dawkirst]

Hi RussB, thanks for the reply.

I found the super cap, disconnected the battery and shorted the super cap's leads with a needle. I gave it power again, but I still can't communicate with it.

I shorted the super cap while the PLC had no power, which I suspect doesn't really matter, because power or not, the super cap will discharge if I short its leads, right?

Am I missing something else? (BTW, I know it's not my serial port on my PC or the cable, because I can still communicate with the other PLC.)

Thanks for your efforts in any case.

 

[Steve Bailey]

Disconnecting the battery and shorting the super cap should restore the PLC to its out-of-the-box configuration which is both ports set for SNP slave at 19200 baud, odd parity, 1 stop bit.

Which port are you using? Since you were talking about multidropping two PLCs, I assume you were using the 15-pin port. If you are using port 2 with an RS485/RS232 converter, check for the presence of 5VDC on pin 5 of the port. That's what powers the converter.

Do you have or can you make a cable for the other port?

 

[dawkirst]

Hi Steve, thanks for replying.

I am using port 2 with a RS485/RS232 converter, and I'll check for a 5VDC on pin 5 as soon as I can get my hands on a multi meter.

I don't have a cable for port 1, but I know someone who has, so I'll ask him for it right away.

Thanks for the input!