RSLogix / Logix Designer - Writing same value in an array

[dalporto]

this video series; watching the first three or four videos in that series at 1.5-2x normal speed will be the most productive half hour you ever spend on this topic.

I don't know what kind of students this guy had, but no, it wasn't productive at all unless we want to go into semantics.


Thanks anyway.

 

[drbitboy]

• Rung 4, top branch: the mask value, if 1 (XIO 1 => False), prevents the value of IN_00 from triggering the OTE to write a value of 1 into OUT_00 There may be a misunderstanding here. I want it (OUTXX) to be high whenever INXX is High. ...

Ah, sorry, I misunderstood.

Anyway, dropping the XIO mask from the top branch of the third rung should make it work how you want.

So the only change is where the XIC mask goes, and as you note, it works either way.

It could also do be done with a TON sealed in via its TT bit, then we eliminate the one-shot logic and everything fits on one rung with fewer instructions overall; see below.

Notes

• The XIC MASK_00 could be on the TON branch or on the TT seal-in branch.
• The TT (Timer is Timing) bit is Allen-Bradley timer shorthand, equivalent to XIC EN XIO DN i.e. (timer input rung is True) AND (timer is not expired/DoNe)

​

 

[drbitboy]

Sidebar: are you aware of the PLC discord? A fair few Quebecois are quite active.

 

[Rsflipflop256]

Hows the library coming? I looked a little and see a nice table of contents without much contents. Is it still moving forward? May I offer any help?

 

[dalporto]

Sidebar: are you aware of the PLC discord? A fair few Quebecois are quite active.

That was misleading.


I was picturing a bunch of angry Quebecers going at it against the rest of the world!


I didn't know Discord, I'm a creature from the "old-school" message boards like this one. I'm an old man.


I subscribed, I'll check it and check I can figure out how to use it.


Thanks Brian!

 

[dalporto]

Ah, sorry, I misunderstood.

Anyway, dropping the XIO mask from the top branch of the third rung should make it work how you want.

So the only change is where the XIC mask goes, and as you note, it works either way.

It could also do be done with a TON sealed in via its TT bit, then we eliminate the one-shot logic and everything fits on one rung with fewer instructions overall; see below.

Notes

• The XIC MASK_00 could be on the TON branch or on the TT seal-in branch.
• The TT (Timer is Timing) bit is Allen-Bradley timer shorthand, equivalent to XIC EN XIO DN i.e. (timer input rung is True) AND (timer is not expired/DoNe)

View attachment 66813​

Yeah, it's cleaner and leaner. Thanks!


I thought it wasn't working at first because when I added the TON I just put a.PRE value in there and I then noticed that when online, the value was 0 instead of the 12000 I put there.


Another irritating behavior from RSLogix I guess.


The screenshots with N7 or T4 you've been posting, it's from Logix500, right? I remember that from a long time ago but cannot figure where I saw that.

 

[drbitboy]

The screenshots with N7 or T4 you've been posting, it's from Logix500, right? I remember that from a long time ago but cannot figure where I saw that.

Yes, Micro Starter Lite actually, so a freebie subset of 500; the memory is file-based instead of 5000's tag-based scheme, and the syntax is more limited, but the instruction set and behavior are more or less the same between the two.

It's close enough most of the time, for the scope of questions that show up in this forum