ControlNet Com Fault

[wmor0082]

I am having communications fault on ControlNet units. I would like to know a good way to troubleshoot problem.

 

[Ken Roach]

What exact sort of "ControlNet unit" is it ? Rockwell Automation and other vendors built dozens of different devices that connect to ControlNet.

Are there any diagnostic indicators on the devices that might be giving you diagnostic information ?

Is this a new installation, or an existing system that has developed problems ?

There are a couple of ControlNet-specific signal and protocol analysis devices but you really want an expert who knows how to use them. I used to do that for a living.

 

[wmor0082]

This is a Rockwell controllogix 5000 that are controlling extruders.

 

[wmor0082]

The connection is through a control net card.

 

[Ken Roach]

From your description I can deduce that the modules in the ControlLogix are probably 1756-CNB or 1756-CNBR modules.

But the motion controllers or drives or I/O devices might be anything, and you haven't given any useful diagnostic information.

If you report some useful information, folks can help point you toward the diagnostic features built into the devices.

 

[nhatsen]

As Ken said before, you need to provide more information:

a) Is this a new installation? Is it working for years without problems?
b) The controlnet module has some leds and a display. Could you tell us if the lights are green/red, blinking, on, off? What information is shown on the display?
c) Do you know the model of the controlnet module? How many cables are connected to the module?
d) Do you have RsLogix 5000 /Studio 5000? Could you go online with the PLC and tell us what error number is shown on the controlnet module's properties?
e) What is the controlnet device on the extruders? What is the state of the indicators there?
f) What's the model and firmware of the controller?

 

[wmor0082]

The card that I am using is a 1756-CN2/A. It is connected through BNC connectors to remote I/O for Drive parameters and temperature feedback.

 

[Ken Roach]

Okay, so what kind of a drive is it ? Again, please, provide as much detail as you can, including manufacturer, model name, model number, and part number.

What exactly do you mean by "remote I/O" ? Are these Allen-Bradley 1734 POINT or 1794 FLEX devices ?

Does your system use the proper ControlNet 1786-TPR or 1786-TPY taps ?

Is your system recently installed ? Has it run correctly in the past ? How long have these problems been occurring ?

Please provide some sort of description of the circumstances of the network fault, and some sort of description of what the indicators on the 1756-CN2 and the drive are showing.

 

[sparkie]

Are you able to get online with this system utilizing RSNetWorx? It would be quite the useful application at the moment.

 

[wmor0082]

I had to leave work today. I will answer all question tomorrow. Thank you for the help. I have your list of question and will answer them all.

 

[Geospark]

I had to leave work today...

I think all the above gave them a headache and they just gave up for the day? (Joke!)...

Don't forget to recharge your Crystal Balls for tomorrow!

Regards,
George

 

[dmroeder]

Don't forget to recharge your Crystal Balls for tomorrow!
George

I about spit my beer out!