Updae:
I found a hardwired workaround for 3 of the 4 changes they want to make, but the last issue does require a program change.
So now the customer is concerned about the existing potential for a failure of the current obsolete PLC and is wheighing the costs/benifit factors of replacement with a current model, or making the program change. Basicly the issue is like this: Spend $2,500.00+ for me to drive or fly and make a minor change to the program and still be left with an unreplaceable PLC; or Spend $5,000.00 and change it out with a new one.
So in short, we're on hold on this one for now.
Thanks Mike.