AD003 stops running

[toolman 0]

What can cause an analog module to drop out of run mode?

[gtsuport 61]

What processor are you using? What is the Mach#/Unit# for the module? Check to see if there is an error code area for the module, and see if that will point you to the problem. Hope that helps.

[toolman 0]

System Overview CS1 Rack (10 slot) C200H-PA204S Power Supply CS1 CPU 44 with SCB21 serial module AD002 M0 DA003 M1 CT021 M3 CT021 M4 OA122 OA122 IA122 OC224 ID212 CS1 Expansion cable 12 meter CS1 5 slot rack C200H-PA204S Power Supply AD003 M6 - This one drops out of run mode DA003 M7 - Outputs stop responding to the program OC224 ID212 This is an intermittant problem. Problem happened twice overnight and went away after cycling power. System has been running fine so far today. CPU fault history showed an IO verification error but all equipment checks OK.

[gtsuport 61]

How long has the system been running (installed)? Has any wiring been changed recently? My first thought is the 12 meter expansion cable may be picking up some noise, causing the unit to drop out. Just a thought. Another thought would be the C200HWPA204S on the remote rack. It may be dipping low enough to cause the error. Again, just a thought. Hope this will help.

[PdL 71]

Believe it or not, I have also once exchanged a rack backplane on a C200H Alpha. Due to corrosion on the rack the card made bad contact. It also caused intermittent problems on the cards.

[toolman 0]

The system has been running in this configuration since 12/2004. However, we are having the same problem we had back then. See my posting from 12/04 http://forums.mrplc.com/index.php?showtopic=3259&hl The problem disapeared after changing the expansion rack from a C200H to a CS1 rack (back in 2004). We have taken the line out of production so we can do some testing and recreate the situation but we can't get it to fault again.

[gtsuport 61]

I would take a look at the connectors on both ends of the I/O connecting cable. See if there is any signs of oxidizing on the terminals. Simply unplugging and plugging in again may be enough to correct the "problem". Last time, when the rack was changed out the problem went away. This would have involved replacing the cable. Again, this is only a thought. Intermittant problems are very difficult to locate. Good Luck!!

[toolman 0]

The last time around we changed the cpu, expansion rack, cable, modules and no luck. This was the point where we went to the CS1 expansion rack. Yes, I have checked and re-seated all modules and cables. Unfortuanatley, since I cannot recreate the problem, an oxidized contact could have already been addressed. When the problem occurs the production run must be scrapped. And since we are already shut down our current plans are to replace the main rack. All suggestions have been greatly appreciated. If the problem comes back I will update with another post.