Clearing out an AB 1747-M11 EEPROM module

BinderNut

Member
Join Date
Apr 2008
Location
ND
Posts
65
Does anyone know a quick way to clear a 1747-M11 EEPROM module? We've got one at the plant that either has a corrupt program in it or the chip itself is corrupt.

The machine sat unused and powered down for about a year, so the PLC battery was dead the the processor memory was blank.
The problem we've got is that on power-up the EEPROM writes a bad communications config when it loads and we can't configure RSLinx to communicate with the processor.

Installed in a 5/03, the module automatically writes the saved program to the processor even though the status bits for the memory module in the program are set to 0 (S:5/8, S:5/9, S:1/10-12, etc).
We normally run with S:1/12=1 so the EEPROM is used as backup in case the processor memory get porked, but this machine has never had that change made yet.

We've replaced the EEPROM with a new one and all is well, but we'd like to salvage this one for use in our training stand if we can clear the program to see if just it or the whole module is bad.

Thanks!
Mike in ND
 
Create a blank program or test program and write that to the memory module in question. Then test the outcome.
 
Last edited:
Create a blank program or test program and write that to the memory module in question. Then test the outcome.

Had a little time to play with this on our test rack (a 5/05) tonight. Same results as on the 5/03 out on the machine that we're recommisioning.

I can "DEFAULT" the processor just fine with the EEPROM module removed. But, whenever I plug that module into the processor, it messes up the comm config as soon as it boots up, even with a valid program in the processor's memory that has all the memoery module status bit set to 0. After booting with the EEPROM installed I can't get online with the processor anymore. RSLinx won't autoconfigure and I've gone through all the DF1 combos trying to find the one that works.
I kinda suspect that the module is toast and it's not just a corrupt program that's messing up the communication settings.


This is just something to do between line calls...hoping we can salvage more parts for our training rig. It's not a big deal, just a head-scratcher that I've never encountered before. I don't post often but I've been lurking and absorbing info for several years now. Great place to find answers!

Thanks for the replies!
 
Follow-up:
The solution was so simple it should have bit me on the nose.

I was overlooking the power of the keyswitch...my previous attempts were with it in the REMOTE position.
I powered it up with the keyswitch on the 5/05 test processor in PROGRAM. The memory module tried to load the botched 5/03 program and promptly faulted the processor. With it faulted and the keyswitch in PROGRAM I was able to configure RS232 comms to the processor. After that it was easy to upload and burn an empty program to the module. Viola, one memory module salvaged.

Thanks for the assistance!
 
Follow-up:
The solution was so simple it should have bit me on the nose.

I was overlooking the power of the keyswitch...my previous attempts were with it in the REMOTE position.
I powered it up with the keyswitch on the 5/05 test processor in PROGRAM. The memory module tried to load the botched 5/03 program and promptly faulted the processor. With it faulted and the keyswitch in PROGRAM I was able to configure RS232 comms to the processor. After that it was easy to upload and burn an empty program to the module. Viola, one memory module salvaged.

Thanks for the assistance!

Thanks for coming back with your solution. I would not have thought of that ( might have stumbled on to it). It will surely help others in the future.
 

Similar Topics

I'm online with a 90-30 using PAC ME 9.8 No one has gotten online with this PLC for many years and the the I/O fault table has a total of 1209...
Replies
6
Views
2,937
Using an L81 - I have the arrangement below that will try the Ethernet Radio first and if that fails use the Cellular Radio. The Failover works...
Replies
16
Views
3,303
Since this is the most helpful place on earth for us programmers, I'm back with another one. Using Logix v32 I've got an array with 100 elements...
Replies
9
Views
2,902
Hey guys, I'm still pretty new to PLC's in general. For a program on RSLogix 500 with a micro1400 and pvp400, we are currently logging data for...
Replies
9
Views
2,784
I am currently working in RSLogix 5000. I have a large data structure with the following general structure: UDT[0] Dataset1 Min Max Avg Data[90]...
Replies
14
Views
4,329
Back
Top Bottom