RSLogix 5000 GSV Instruction

Hello everyone,
I am having an issue with random I/O faults on a ControlNet network. In the logic, there is a GSV instruction with LedStatus as the attribute and as long as the LedStatus equals 3 it says the communication is ok. When an I/O fault occurs, the value is going to a 2. There are several of the GSV instructions in different controllers. My question... in the GSV instruction that is going to a value of 2, is there any way to find out exactly which controller that specific instruction is monitoring the led's of? The reason I ask is, the attribute name(LedStatus) is the same in all of the GSV instructions.

Thanks

The LedStatus is just a mirror of the I/O Led on the controller front (or the module front, if the instance name is a module).

You can use RSLogix, RSLinx and RSNetworx to troubleshoot the issue.

Finally, you need to provide detailed information about your system if you want some further help from the forum.

Thanks nhatsen for the quick response. We have 8 different cpu's and numerous controlnet cards and approx. 80 nodes on the system. The instance is a module. I am trying to figure out what the GSV instruction is monitoring. Is it monitoring one of the cpu's or is it monitoring one of the controlnet cards?

The GSV as you have described it is an instruction that tells the CPU to monitor its own I/O LED. It cannot tell the CPU to look at a different controller. Ideally all controllers would be monitoring all of their own modules.

Often times the LEDStatus being set to something other than "3" is used to trigger other GSV instructions to check the status of other modules. For example, if i know the LED is flashing green then i will trigger GSVs to report the status of all modules in the local chassis. If my comm module has an error then I can trigger other GSVs to check the modules in the appropriate remote chassis.

LED status is specific to the controller so the instance would be blank. But other attributes can be monitored and in that case the instance is the specific module. It uses the module name from the I/O Configuration.

OG