SLC 5/05 faulted after online edit, can't get it to accept IP address

defcon.klaxon

Lifetime Supporting Member
Join Date
Feb 2015
Location
Far NorCal
Posts
616
Hi all,

Working on a SLC 5/05 that occasionally faults when a new program is downloaded; replaced the battery but that hasn't seemed to fix it unfortunately. It's happened a few times before so my typical go-to is to pull the CPU, remove battery, short capacitor and then download the program.

Unfortunately this hasn't worked this time; I've got a blinking fault light, a solid green ENET but the CPU doesn't respond to ping. So I opened DHCP-BOOTP Server and I see the requests, and I've given it an IP address and now it responds to ping. Great I think, now I just need to download the program. But every time I try to download, RSLinx 500 says it cannot download to the PLC, it has "communications errors".

I will note that I can't disable BOOTP/DHCP in the Server; when I try it says "Connection refused".

Any thoughts on how I might be able to get this CPU to behave?

Thanks!
 
- Tried to download with serial cable with DF1 driver?

- You can also try to reset the processor by pulling the battery and shorten the contact between GND and VBB for about 60 seconds.

- Update the firmware
 
quick update: after doing some Google searching and reading some similar articles I can say the following:

arp -a verified that the PLC's mac address is correct
putting the IP address of the CPU into a browser brings up nothing, no diagnostics

also noted that whenever RSLogix tries to write the executable, I get a "not responding" error with the program before it comes back and says the download failed. not sure if that means anything or not.
 
Last edited:
- Tried to download with serial cable with DF1 driver?

Have not, no; there's a DF1 plug into the CPU but I'm not sure what it goes to; I don't have one myself but I'll see what the plug goes to.

You can also try to reset the processor by pulling the battery and shorten the contact between GND and VBB for about 60 seconds.

I've tried that several times but it wasn't for 60 seconds; should I try that again for that long? I was doing about 20-30 seconds.

- Update the firmware

would that help if the CPU was running earlier today, and I've been able to work on it before?

If so, can you point me to instructions to do so?


Thanks!!
 
60 second on reset is just what I read here in other threads. I guess it doesn't hurt to try.

I would try the serial download first, you will need a standard null-modem cable and a USB-Serial adopter cable if you don't have a real serial port on your PC.

As for firmware update, 5/05 firmware have to be bought from Rockwell that comes with the firmware and instruction. I had to do that once on a real old 5/05 in order to add some new functionality. In other discussion here, that's one of the option to improve stability. In your case, I would attempt the serial connection first.
 
60 second on reset is just what I read here in other threads. I guess it doesn't hurt to try.

Gotcha. Tried that, didn't seem to help.

I would try the serial download first, you will need a standard null-modem cable and a USB-Serial adopter cable if you don't have a real serial port on your PC.

I have the hardware for that, but I'm not sure how I would set up the connection; would I go into RSLinx and create a DF1 master and then go from there?
 
Yes, first, you need to disconnect the other serial cable and connect the null-modem cable to your PC.

Once connected to your PC, determine the com-port used by going into Device-Manager and look under Ports. Now open RSlinx and Add the RS232-DF1 driver if you don't have one already.

In the configure screen, set the com port and the device to SLC-CH0 and click on the Auto-Config button.
 
Based on nothing but hearsay and speculation, but...

Check the chassis grounding and improve it if necessary
Replace the power supply

Probably 75% of the time I see threads about an unusual/weird issue arising on an SLC chassis, properly grounding the chassis and/or replacing the power supply seems to make the problem go away. You wouldn't *think* that it'd be related to your specific problem, but I've thought the same thing a whole lotta times, and been wrong.
 
OK, so strangely when I restarted the computer and tried again, I was able to successfully download the program via ethernet and it was up and running. Not sure why that helped, but that seems to be the solution today.

Yes, first, you need to disconnect the other serial cable and connect the null-modem cable to your PC.

Once connected to your PC, determine the com-port used by going into Device-Manager and look under Ports. Now open RSlinx and Add the RS232-DF1 driver if you don't have one already.

In the configure screen, set the com port and the device to SLC-CH0 and click on the Auto-Config button.

Thanks for the walkthrough Harry, I will definitely backpocket this info in case I ever run into this issue again.

Based on nothing but hearsay and speculation, but...

Check the chassis grounding and improve it if necessary
Replace the power supply

Probably 75% of the time I see threads about an unusual/weird issue arising on an SLC chassis, properly grounding the chassis and/or replacing the power supply seems to make the problem go away. You wouldn't *think* that it'd be related to your specific problem, but I've thought the same thing a whole lotta times, and been wrong.

That is very interesting, thanks for chiming in with this info. Next time I'm on site I will definitely take a look and see if grounding can be improved and will see what a replacement P/S would cost.

Thanks guys! This forum never ceases to amaze me with the help it provides.
 
+1 to replacing the power supply and checking the ground. Mine would drop its program whenever the power was cycled but ran with no issues in every other sense. The problem was with the power supply and cleared up as soon as it was replaced.
 
+1 to replacing the power supply and checking the ground. Mine would drop its program whenever the power was cycled but ran with no issues in every other sense. The problem was with the power supply and cleared up as soon as it was replaced.

Thanks for the +1 on this.
 
Update RSLogix 500

I ran into the same problem on a system several years ago. The only way I could recover was to download the program using the serial port. It turns out the problem was a bug in the version of RSLogix 500 I was using. I updated to a newer version and didn't have any more problems. There was a Rockwell Knowledgebase article describing the problem.
Are you using a recent version of Logix 500?
 
I ran into the same problem on a system several years ago. The only way I could recover was to download the program using the serial port.

I am definitely going to get all the necessary provisions for serial port connection, sounds like a valuable tool to have.

It turns out the problem was a bug in the version of RSLogix 500 I was using. I updated to a newer version and didn't have any more problems. There was a Rockwell Knowledgebase article describing the problem.

That's really interesting.

Are you using a recent version of Logix 500?

I'm not sure what version it is, it's probably very old. Originally the system was installed in 1999 and I wouldn't be surprised if Logix 500 is several updates removed from most recent. I'll take a look at this too, thanks!
 

Similar Topics

Hey guys, I'm currently at a wastewater plant where I needed to make a simple edit of a SLC 5/05 scaling block, but I guess it got messed up when...
Replies
11
Views
2,380
Hello Everyone. I was downloading a project to my PLC503 and the progress corrupted during the download. I got a flashing fault, I switched to...
Replies
2
Views
1,488
Hi all, Just got a call from one of my clients, there has been a ton of lightning around me they got hit. Turns out the SLC 5/05 was faulted...
Replies
8
Views
2,112
I have two SLC 5/05 PLCs which are displaying faulted under RSLogix (see attached picture). However, the faulted LED is not lit on either PLC nor...
Replies
23
Views
4,908
Here is the thing... A customer reported several times PLC module faulted without any reason after 8 years of continuos working, according to...
Replies
6
Views
3,161
Back
Top Bottom