Logix 5000 Question...?

shoelesscraig

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Join Date
Apr 2009
Location
LA
Posts
382
I know I've seen the answer to this before, but I've searched and searched and for the life of me I can't find it!!

I'm used to Logix 500, where if I wanted to make an output flash I could use a bit such as S2:4/5 for example. What is the easiest way to do this in Logix 5000? I know how to do it with 2 timers, but I thought there may be an easier way...?

At first I HATED 5000, but the more I get used to it, the more I love it! I'm just still trying to get used to these little differences.
 
Scan time for a typical program in this controller is just a few milliseconds. I'm looking to flash an output (such as a pilot light) on and off a LOT slower than that. Maybe 1 second on, 1 second off. Or .5 seconds on, .5 seconds off.
 
hmm.. could you use system clock &2 (& being the remainder operation) and toggle on it?
 
One part of my utility logic for Logix is a simple free-running timer, with a 50ms time base. Every time the DN bit gets set, I just add 1 to a DINT. Just use the bits of the DINT for various duration blinker bits.
 
One part of my utility logic for Logix is a simple free-running timer, with a 50ms time base. Every time the DN bit gets set, I just add 1 to a DINT. Just use the bits of the DINT for various duration blinker bits.

Great idea. Correct me if I'm wrong, but won't I need to limit the DINT somehow to make sure the number doesn't get too big? If so, can't I just unconditionally unlatch one of the DINT's higher bits? Say for example bit #30 in the DINT? I may be off track here...?
 
There are a few ways of doing it for different results, but here's one quick and dirty way I use if I just want to make something flash.

Just use bit Blink_DINT.0 to Blink_DINT.13 to vary the rate, or combine a couple of bits for different blinking effects.

Blink.JPG
 
If you are using a DINT you can do the Unlatch in the bit .31 and get more blinking values. habe any one tried to do that, is the blinking to slow ??
 
If you are using a DINT you can do the Unlatch in the bit .31 and get more blinking values. habe any one tried to do that, is the blinking to slow ??


Unless you want to grow old waiting for bit 13, you won't need anything higher.... So really, you could use an INT, but yeah.
 

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