AB SLC "Always on" status bit

Rick.

This is from the help-file:

This input instruction disables its rung when inserted in the condition side of the rung.

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This is what I said:

This will disable scanning of the rung after the AFI instruction. (example with AFI in the beginning of the rung).

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What is the difference ?
Obviously I was wrong - is it necessarry to discuss WHERE I was wrong ?
(its kinda embarrashing, you know).

For SLC programs I always have an always-on TRUE, an always-off AFI and reference an output NOP. That way I can enter the symbols the SLC doesn't have.



---------------------(TRUE)


-|/|--||-------------(AFI)


---------------------(NOP)


As far as 2 bits TRUE and AFI, for me it's less confusing, and at my age that's beginning to help.

Holy resurrection Batman!

janner_10 said:

Holy resurrection Batman!

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Note that I_Automation was not the one who actually resurrected it, that 'honor' goes to a spammer an hour earlier who got his post deleted and his account banned as a prize.

here is my reason.

we bought a 4 station machine and the vendor had to do a lot of debug work.
they picked random bits and turned them on of off to debug. lots of bits.
they forgot several and someone turned the bit off and one station quit. i got the call at 11 pm and didn't figure it out until 3 am. we got lucky and he did the same thing on another station. i corrected the logic and got home at 4 am.
from that point on, i mandated that the first rung of logic would be an always off bit, and the second would be an always on for debug purposes.
that was *0 years ago, and i still hold to that rule every where i go.

i have not had that issue since the rule was implemented.
james