DH+ errors only one node (a PC)

I have one node not communicating very well with the PLC's (all of them), total 10ish nodes 2PC's and the rest are SLC 504's

One of the PCs is having a hard time with the com's are there any settings? its the only node that is not working correct.

If I hit retry it will start working again... for few min or sometimes 10sec then errors out again

I have check all the connections and it has the resistor, so is there another setting?

It started after I changed out the PC, so I may not have something set correct

Well, since it is a PC you can us RSLinx to monitor its health.


If its a KT card or wiring problem, you will see retries and errors and I think there are token statistics too, unlike a PLC, though, you don't have to assign a diagnostic file...

For starters, in RSWho, right click on the node in question, and look at station diagnostics IIRC...



Oh, by chance, does it only happen during a certain online editing sequence?

Hi Paul,

Never done that, so I am not sure of what I am looking at... is it driver diagnostics? does this tell you much? nothing under log





EDIT: Went to the other PC and its giving me more data... give me a few and I will be back to post the findings from the other PC

CRS...I would also poke around in driver diagnostics...I think it is under menu: Tools

EDIT: You ARE in driver diagnostics. Look for Station Diagnostics, if it exists...

Packets outstanding looks suspicious, does that mean lost packets between RSLinx' software clients (RSLogix) and the KT-card?

How many nodes? lots of messaging? lots of remote monitoring? The SLC is a puny communicator compared to a PLC5.

Maybe one or more nodes is dropping messages or the token...too many messages...not enough buffers/channels? Pure speculation on my part...

So, does it happen only during online editing? Online editing is a sure-fire way to put a spike the SLC housekeeping time...

I had to go to the other PC to see 'Station Diagnostics' (guess you can not diagnos yourself)

here is the screen shot from that one... I VNC to the other and made sure a error happened while I was monitoring it..

And this only happens on this PC not the other one

Wish I could be more help.

I suspect the problem is on the PC itself. Maybe the KT card has a problem. Maybe there is a software issue causing the trouble.

Oh, Mr. Roach? Where are you?

Uncheck the "Autobrowse" in RSLinx after it finds all nodes or close RSWho no need to have it running after it finds all the nodes. This has helped solve a problem like yours for me.

What OS are you using?

What DH+ card?

Are you sure you have the most current drivers from AB?

It is a PKTX card, right ? Not a KT or KTX ?

I remember something about the first versions of the PKTX cards should work with 5V PCI bus only.
And something about later versions supporting both 5V and 3.3V PCI bus.
So if your PKTX is one of the early versions, and you installed it in a new PC with 3.3V PCI, then that could be the explanation.
I am just mentioning it. Actually I would suspect a 5V card to refuse totally to work in a 3.3V PC, rather than working some of the time.

Other things to try is to reinsert the PKTX card in a different PCI slot.
Or to try it in another PC.

You mentioned it was a PC. Have you looked and seen what software is running in the background. Could it be possibly one of the virus checkers or some other program connected to the internet that hogs the connections one in awhile.

I have the same problem once in awhile with my laptop. Another laptop gets on and never loses the connection, but mine acts up sometimes. I know it one of my many software programs causing it but so far I have not investigated any futher.

also look under task manager on the PC, close off all tasks which are not critical a fresh installed operating system will try to run a lot of unnecessary tasks such as auto updates which can tie up your processing time. Take a close look at CPU usage at the time your connections drop out. You may see 98% system idle which 've seen cause problems. Also check your commport send and recieve buffers under control panel try increasing them and see if you improve your packet losses. Ping -t the other PC look at your TTL. Its also possible you need to adjust your MTU settings under the windows registry you will have to search the net on how to do that so I would save that as the last step. Knowing what operating system you are using may provide us some better direction on how to assist you

Thanks guys.... I will look into them all

I will repost when/if I ever find the issue(s)

Thanks again
Mark