MicroLogix 1500 programming Question

Hi

New to forum so Hi folks.

I have a question about an Allen Bradly Micrologix 1500. I want to write to a bit that will stay on when the machine is powered down.

I am using a hold down for 5 seconds on the start button input to select another machine mode. After 5 seconds I was turning B30/1 and turning it off by holding it on for 10 seconds.

Code works 100% apart from power down. When re powers goes back to default state 'forgetting' the setting.

I imagine ther is abattery backup Bit we can write to. Any suggestions?

Thansk for your help.

Aaron

Greetings Aaron,

try using a "latch" (OTL) instruction ... you'll probably need an "unlatch" (OTU) instruction on another rung to turn it off ...

PS edit: the first post in this thread should help give you the idea ... but it's probably a lot more information than you were looking for ...

the basic idea behind Allen-Bradley "latches" is that they are "retentive" ... secret handshake: they can "retain" their ON status after a power cycle ...

and welcome to the forum ...

Cheers Ron

Now works 100%! Knew it would be simple.

Thanks for your help!

Aaron