1756-CNB/D assert: error

I have a chassis with 3 1756-CNB/D cards in it, about once every 2 or three weeks all 10 AB Powerflex 700 drives on this one card fault out, I go to the cabinet and the ok light on the front of the card is red and the following error message is scrolling across the display:
Assert:Null.C line 0445
I have done some surfing on the knowledgebase but no luck with this error.
Thanks in advance for any help

I have never seen that CNet error myself. However, if you want to at least find out if is the card itself, or the network, I'd swap the suspect card with one of the others in your rack. If the same drives fault out, then you know that your card is fine and that you have an issue with the media or one of the drives. If the new network faults, then you know that the card is bad.

Do you know FW rev for your CNB?
Also FW rev for 20 COMM-Cs?

kbpatton said:

I have never seen that CNet error myself. However, if you want to at least find out if is the card itself, or the network, I'd swap the suspect card with one of the others in your rack. If the same drives fault out, then you know that your card is fine and that you have an issue with the media or one of the drives. If the new network faults, then you know that the card is bad.

Click to expand...

Thats an excellent place to start troubleshooting and if i havent nailed down a solid answer by this weekend i will give it a shot. Cant power down till then production runs 24/7

Contr_Conn said:

Do you know FW rev for your CNB?
Also FW rev for 20 COMM-Cs?

Click to expand...

yes CNB/D 5.1
looks like 20 comm-cs is 1.001 I will have to verify

thanks
Kenny

Definitely check the ControlNet modules (and the controller) for the "Atmel64" backplane ASIC chip issue. It sounds like a defective 1756-CNB component to me.

Ken Roach said:

Definitely check the ControlNet modules (and the controller) for the "Atmel64" backplane ASIC chip issue. It sounds like a defective 1756-CNB component to me.

Click to expand...

Thanks Ken
not sure exactly what a Atmel64 is? but i will dig into it.

also if it helps any,this system has been up and running and untouched (as far as i know) for about 5 years and this intermitten issue just started a few weeks ago.

Ken
does that have something to do with the way the controller interacts with the chassis backplane??
I found something similar on knowledgebase.

I should have been more specific; in the A-B world this was a well-known chip problem that affected a lot of controllers, network modules, and motion modules. There was a bad batch of backplane bridge chips, and the batch was from Atmel and had a batch number printed on the chip that ended in "64". Chips from Samsung and Phillips and Atmel chips that ended in 65 were not affected.

The issue was called ACIG 2007-05-002; you can search for that in the Knowledgebase or go directly to Articles 40149 and 41204.

Since your system has been running since before the bad production batch it might not be affected. Also, most of these failures appeared right away when the system was commissioned. But when you're dealing with a crash of the firmware in the 1756-CNB, you have to rule this issue out before proceeding.

Thanks Ken
good info
I will keep digging