ControlNet Module LED Status

Hello,

First of all I'd like to say this is my first post to this board although I have been lurking around reading posts for a while.

I would like to extract the LED status from a ControlNet module 1756-CNBR (redundent media). I have checked the AB knowledgebase and know about the option of using a CIP MSG instruction, but to do this I would need to create a UDT in ControlLogix. I can not take the processor down or put it in program to create a UDT since it is in a running plant.

I also know how to extract fault data using a GSV instruction. The problem is the ControlNet module does not display a fault if one of the two Controlnet connections is bad. The module is always happy as long as one of the two connections is OK. The only way I know how to monitor Ch A status and CHB status is by looking at the LED's on the module. Currently my ChB is down, and the LED is flashing red, but the module does not report a fault code.

I doesn't seem possible to extract LED status using a GSV instruction.

Anyone have any ideas?

I will state that I know nothing about Controllogix but reading the manual from AB it seems that if a connection is lost the modules status bits will show it, maybe those could be monitored.
http://www.ab.com/manuals/cl/1756653.pdf

Another option is to use something like a heart beat or always on bit and monitor it for loss of communication.

ControlNet LED Status

Dear all,

I have the same problem, too. How can I Solve it ?

I searched the RA/AB KB long and hard to find the same thing. There was one tech answer that flat out said, monitoring of each redundant network can't be done. I played with the GSV block reading various CNBR module properties, but as you said, it doesn't have a GSV module flag if one of the two controlnet rendundant networks go out.

I worked at an OEM where I believe we did this, but it was propietary. If I figure it out in the next couple of months I will post.

The same topic was brought up just yesterday. You can read the ControlNet physical interface status and redundant media status with one CIP generic message instruction (more elemental than a GSV).

RA Knowledgebase documents 16584 or 18423 describe the same method of access to the ControlNet Object.

You could make the target a SINT[x] array and just parse out the elements you need with COP instructions. No need for a UDT.

Hi All,
Did anyone manage to achieve this? I am looking at the same issue now so will check out the use of CIP message...