1756 DNB Status Structure

Hi All,

I am working with a 1756DNB and looking to use the Device failure register to pick up that eg my node 01 E3 device has lost communications. I would like to use this feature in my CLX program.

I can’t seem to find any information on how this register works, and hence which address should I use to display I have a device failure?

Can anyone give me an URL, so I can do some more reading up on this, I can’t seem to find much else but the basics?

Thanks

Ben

Manual

It starts at 12-13 (adobe page 175 of 239).

The Device Failure registers are an array of 8 SINT tags, so that one bit corresponds to one possible DeviceNet node number of 0 to 63.

Local:1:S.DeviceFailureRegister[0] - [7].

There will be a "1" in the bit position corresponding to the node number if there has been a communication failure. If communications with Node 23 fails, for example, bit

Local:1:S.DeviceFailureRegister[2].7 will be "1".

I actually prefer to use the Device Status array. That provides one SINT for each node, instead of 1 bit per node, and gives the status code for the slave device connection.

With the Device Status array, a failure on Node 23 would result in

Local:1:S.DeviceStatus[23] having a value of "72" or "78" (connection failure or messaging failure).

This is especially handy for devices that might also experience size mismatches, Idle states, or identity mismatches.

Thanks

That makes it clear. For a while I wondered why the fault moved (also) into the first sint location about 11 sec's after disconnection of a node. Of course its the scanner at node 0 showing the failure.
Clever stuff. I must try harder not to bother you lot.

grs said:

Manual

It starts at 12-13 (adobe page 175 of 239).

Click to expand...

Hello, do you still have this document or a more modern version of it?

Hi, and welcome to the forum. Here it is:
https://literature.rockwellautomation.com/idc/groups/literature/documents/um/dnet-um004_-en-p.pdf