Status Bit when using latching outputs 2

[drkildow]

Trying to write my first program in many years, using RS Logix 500. I can't seem to get my latched outputs to unlatch in a power loss situation. I think there's some way to accomplish that using a status bit, but I can't seem to get it right. Can anyone tell me how to accomplish this. Thank You.

 

[baxtersdad]

Try using the first scan bit to unlatch the latched output. This is a "one-shot" bit which is asserted during the first program pass after powerup.

 

[ADMIRALKEN]

In the SLC & ML product lines the first pass bit address is: S:1/15

 

[ADMIRALKEN]

So....

You can use the bit for each latch such as:
S:1/15
--] [-------------(U)-

or move a zero to an entire register:

S:1/15
--] [--------| MOV |
|A: 0 |
|B:O:1|
|