Panel View Communications

I have a Panel View 550 kepad and touch running on DH-485 thru the RS-232 port. It losses communication with the netowrk at random. I have it communicating with a Micrologix 1500 and every once in a while i will see the message "no active nodes found on network". In RSLinx, it will be there and then all of a sudden, it has the red X over it. I have tried diffrent programs in both the PLC and the panel view but i am still getting this error. Can anyone offer any suggestions as to what might be wrong, any help would be appreciated

Thank You...

It maybe a momentary power loss, external noise,a long comm cable run between PV and PLC, or something else. I would put a small UPS to feed the power for it to see if that helps. If you can change the baud rate to a lower value, that might help.

Are you downloading to PLC or changing from RUN to Program mode?

I am not changing from run to program mode, I just leave everything in run mode at all times and I have this communication problem. I have even taken the panel view out of the machine and I am currently running at my desk and I still get this problem.

Greetings:

I had a similar problem last year while programming a vacuum laminating machine. The problem seems to be the operating system on my laptop (Win XP PRO). A call to AB tech service told me "well, thats the way it is." I even get some nasty warnings when I attempt ot load the drivers. Online editing to a SLC 503 is almost impossible.

Charlie

Charlie
I would check the cable between the PLC to the Panel.
Shut off all the frequency drive(if you have) and wait to see if it came again.
If your panel out of the cabinet take the panel out and check in the lab. if the communication OK. if not you my have problem with the panel view.Try to replace with another one if you have one.

Good Luck

Just for the heck of it, check your comms setup on both the PLC and the PV to make sure that:

A.) The Max Node Address is the same on both. I've had this cause some pretty strange behavior in the past.
B.) You mentioned a "network". Be sure there are no duplicate node numbers being used. Had this happen one time when I accidently left my laptop configured as Node #10 and plugged into a network that had a SLC configured as Node #10 (oops!).
C.) If this is DH485 network with multiple nodes (maybe you're linking using AIC's or NET-AIC's), be sure your physical ends of the network are terminated correctly.

HTH
Jeff

Jeff:

Thanks for the tips. I'll check it out. I also have the latest version of RS logix to install and hope there may be some enhancments there. AB told me there were some conpatibility problems.

Thanks again.