PLC-5/20 Download Problem

Hi All,
I need to download an older version of a program to a PLC5/20.
Seemed easy enough. I am getting a constant error massege. Then download will stop. I don't think the problem is a corrupt file since I have tried 3 or 4 different versions from different sources. I first tried to download the file on my laptop hard drive. Then I tried a different version from the server backup hard drive. Don't have a clue at this point as to what to do. The current program in the PLC is corrupt and won't run at all. Can anyone help? Maybe I need to clear the processor memory and satrt from scratch.????
Here is the error message:

Download Failed!
Download Write Failed!
Insert Instruction Failed: Ext Sts=0x12
Invalid Parameter in Command
section=Program,file=2, element/offset=1959,length=198


Thanks for any help.
Tony

Maybe I need to clear the processor memory and satrt from scratch.????

Click to expand...

This is a first thing to do: remove battery annd cycle power.
Processor will be reset to default.
Please remember that serial port will be also reset, so you may have to re-configure your DF1 driver, if used.

Greetings Tony,

I’ve never run into this one before ... so all of this is a “best guess” attempt at an answer ... anyway this part of your error message:

Invalid Parameter in Command
section=Program,file=2, element/offset=1959,length=198

Click to expand...

seems to indicate that something in your program file is corrupt ... if you can open the file offline, take a look at Ladder File #2 ... evidentially there is an “invalid parameter” in one of the instructions ... how it got there is a mystery ... the trick now is to find it and correct it ... as long as there are no “secret proprietary code” issues then post your program file and we’ll help you look for the culprit ... if you need help posting your program file, this post should help ...

and welcome to the forum ...

Hi.
I was able to correct the issue after 4 hours of head scratching.
The first instruction on rung 598 didn't have an address asigned to it. Just an XIC with no lable at all. File #2 has 927 rungs, took me a while to find the bugger. I made an executive decision and deleted this bit. All is working as normal. How the program got saved to a floppy, then to the server with that error is still a mystery though. We have been working with this file over the last 2 weeks. It is a palletizer. Our management determined we needed to add another pattern. Well, the factory rep was 2 weeks overbooked so the boss says, "Make it happen".
Anyhow , I am going to guess one of our 3 techs was online editing and made this error.(couldn't have been me!) Since the machine runs almost all the time, we never took the time to do a proper download of the program. Instead always doing the online edits. I am a little disappointed that AB software would let us save the file with such a glaring error like this though.
Live & Learn
Tony