After a power outage, Logix5561 lost the program?

Hi, guys, how’s going?

Two weeks ago, after a power outage, Logix5561 lost the program, so we had to download the program to the controller.

Then we installed a new battery (which we bought 2 years ago). But the same issue still happened after a power flicker yesterday.

We checked the battery with multi-meter, it looks like OK, cuz there’s 3.2V on it.

Could somebody give us a hand to fix it?

Thanks a lot.

If battery fault led is on, it's not good. Why don't you write the program to nonvolatile and make the controller boot from there?

Which version of controller do you have? Series A or B?
See this post...
http://www.plctalk.net/qanda/showthread.php?t=70879

KuulKuum said:

Which version of controller do you have? Series A or B?
See this post...
http://www.plctalk.net/qanda/showthread.php?t=70879

Click to expand...

As far as I remember BA1 battery on BA2 connector or vice versa, unless you do a little wire cutting/soldering/isolating. Connectors are pretty different. But if it is in good condition, even then it can do for a while and no Batt Fault will be present.

That's a Series B controller, since it has the CompactFlash slot on the front instead of the bottom.

The solid red BAT indicator is proof that the controller isn't being backed up by the battery, regardless of what the terminal voltage is.

My understanding is that the -BA2 battery had better performance and longevity to match the hardware of the Series B controllers. While they're both nominally 3.2V lithium batteries, A-B intentionally changed the connector so that Series B controllers would get the power they needed to meet the specs that were advertised.

A-B used a bright blue shrink wrap on the 1756-BA2 batteries; the one shown is probably aftermarket.

Maybe the pin assignments are wrong, or the connector is damaged internally, or there's something else wrong with the controller that's preventing it from properly receiving battery backup power.

The short term solution is to use a CompactFlash card to back up the program, and carefully evaluate the system to be sure it can survive the loss of current tag values because of the loss of volatile memory.