SLC5/03 Major Error

Hi: I have an SLC5/03 faulting (major fault) from time to time due to "50" errors " (A chassis data error is detected on various slots). My question is...is there any way to stop the major fault from happening for these faults, until we can get a look at the noise and possible chassis issues, as recommended by Rockwell? This is a very non-critical application and lost or corrupt chassis data for even a few seconds would not cause anything dangerous or destructive. Has anyone seen a method to prevent hardware errors from shutting down the PLC?

There isn't.

If the error was limited to a specific slot and that slot wasn't critical, you could inhibit the slot and the controller would ignore errors from that module.

But SLC-500 controllers are fanatically protective of their I/O integrity, and check the backplane for errors every scan. In the SLC operating system, if anything's "out of control" then it shuts everything down.

Hi Ken: That doesn't surprise me because of potential "abuse". What do you recommend for intermittent "A50, B50, and C50" errors? Where do you start when it comes to possible noise causing this. Noise where? On the PLC power supply input, or?? Slot A is a RIO scanner, B and C are analog input cards. Only see the fault on these slots. Thanks!!

If you're getting faults on all three slots, there's likely a grounding problem.

Start by double-checking the bonding of the SLC chassis (there should be a threaded post on the bottom of the chassis) as well as the ground terminal on the power supply.

Next, lift the shield wires on each analog input and on the RIO cable, and check for any voltage to ground.

Damaged or defective SLC-500 chassis and power supplies are notoriously difficult to detect except by replacement. The SLC is so popular and so reliable that these are uncommon, but by no means unheard of.

bluenoser337 said:

Hi Ken: That doesn't surprise me because of potential "abuse". What do you recommend for intermittent "A50, B50, and C50" errors? Where do you start when it comes to possible noise causing this. Noise where? On the PLC power supply input, or?? Slot A is a RIO scanner, B and C are analog input cards. Only see the fault on these slots. Thanks!!

Click to expand...

I'd probably get a look at the noise on the RIO scanner and its cabling and/or inhibit the slot fault as noted above.

Thanks Ken !! Much appreciated!! :nodi:

One other thing to look at...I have seen faults like you are describing on a couple different machines we have here. These machine vibrate and shake pretty violently and regularly and the problem ended up being a bad chassis.

Hope this helps
-Dave