slc150 question

Hello all, we are currently having a probelm with a AB SLC150. Every time we lose power, even for just a second, we lose the program. We then have to reload the program using a hand held programer. We have installed a new battery but this did not help the issue that I was told has been occuring for a long time now. We have also lost the program in hand held programer and have to reload it step by step. The program used to be in the hand held and we just reloaded it very quickly. This is very time consuming and fustrating to have to reload everytime power is lost. So my questions are:

What could be causing the lost program with lose of power?
Is there something I can check out?

Is there a way to get the program back into the hand held programer? Maybe upload it after the program is in the plc.

Thanks for any help you can give.

MRT19

Is there an EEPROM in the SLC? I have two of them and they both have programs stored on EEPROMs plugged into the front of the SLC150. I use a laptop running the old dos stuff to program them and always must write the program to EEPROM before it will even allow me to put it in run mode. I have no experience with the handheld programmer.

Paul

SLC 100-150 Manual
SLC 100-150 EEPROM User Manual

mrt19 said:

... The program used to be in the hand held and we just reloaded it very quickly....
Is there a way to get the program back into the hand held programer? Maybe upload it after the program is in the plc.

MRT19

Click to expand...

I don't know how the program didn't clear from the Handheld?
Maybe a real short power glitch is clearing the memory in the PLC, but not in the Handheld?

You need an EEPROM like Okie says (PDF LINK)

This Service bulletin shows that others have seen similar problems.
Good Luck

Or maybe its time to just bite the bullet and replace the SLC150. If you have other PLCs and already have programming software such as RSLogix then you can make the change for only a couple hundred dollars.

In the mean time, put a UPS on it (just the PLC, not the whole machine).

I think you should replace this old PLC before in pukes completely. The SLC150 was great in its day, but that day has long past. I'm thinking it has a power supply problem, and that is why it loses the program. I would really strongly recommend upgrading it before it dies completely.

First, thanks to all that have replied!!

I have learned some info about the hand held or pocket programer. The program is not stored in the programer. It is stored in the eeprom chip, the programer is used to transfer the program from the chip to ram memory of the plc. When we lose power the program is lost in ram but the chip.

I am planning either to replace the plc with something more familiar and newer or add a ups to maintain power in the event of a power lose. The only thing is we are planning on removing the line from operation in 6 to 12 months so I am not sure how much money they will let me spend on it.

Thanks again and have a good weekend....

MRT19

A UPS is probably the best short-term solution.

Hey MRT19! You might be able to avoid all that by adding a line of code to the beginning of the program to force the PLC to always load from EEPROM if there's a memory error including loss of the program:



The explanation is at the bottom of Chapter 17-4 in the manual.

That's how ours are done and we've had no trouble with them. They get powered down every night for cleaning and stay down most weekends.
Paul