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Search: Posts Made By: drbitboy
Forum: LIVE PLC Questions And Answers Today, 01:32 PM
Replies: 29
Views: 738
Posted By drbitboy
heh, good one. Took me a bit: I was...

heh, good one.


Took me a bit: I was thinking "No, 18 furlongs is a correct answer;" then, that dawning moment of comprehension we live for.
Forum: LIVE PLC Questions And Answers Today, 12:35 PM
Replies: 29
Views: 738
Posted By drbitboy
18 furlongs. or one and a half Belmonts.

18 furlongs. or one and a half Belmonts.
Forum: LIVE PLC Questions And Answers Today, 12:27 PM
Replies: 22
Views: 574
Posted By drbitboy
This is semantics, but I think considering...

This is semantics, but I think considering "pre-scan" to be a scan in any form is misleading. My semantics in saying it is not a scan is, I hope, analogous to daba inferring it is not a proper scan....
Forum: LIVE PLC Questions And Answers Today, 12:04 PM
Replies: 22
Views: 574
Posted By drbitboy
Oh dear. I am not suggesting this, no, not in...

Oh dear. I am not suggesting this, no, not in the least!!!


I only put the un-called program file (LAD 3) in there to make the point that some versions of A-B PLCs will look at (not scan) them...
Forum: LIVE PLC Questions And Answers Today, 10:09 AM
Replies: 22
Views: 574
Posted By drbitboy
Dust, sackcloth and ashes

Thanks daba, yes: that was MY BAD.


The bit O:0/0 was retentive and did not get assigned to 0 during the switch to program mode, even though the external output relay did go off (I heard it...
Forum: LIVE PLC Questions And Answers Yesterday, 10:20 PM
Replies: 22
Views: 574
Posted By drbitboy
See the image of the program below for an example...

See the image of the program below for an example of what daba is talking about.

Say that PLC mode is [Run], and [The output] (O:0/0) has been latched to 1.

If the PLC mode is then switched...
Forum: LIVE PLC Questions And Answers Yesterday, 08:35 PM
Replies: 29
Views: 738
Posted By drbitboy
multiply by one. several times.

multiply by one. several times.
Forum: LIVE PLC Questions And Answers May 24th, 2020, 09:10 AM
Replies: 61
Views: 2,710
Posted By drbitboy
Semantic nit: oh they will definited go into an...

Semantic nit: oh they will definited go into an infinite loop, with a glad cry 'n all, but of course they will not stay there if there is a watchdog timer.
Forum: LIVE PLC Questions And Answers May 24th, 2020, 08:39 AM
Replies: 61
Views: 2,710
Posted By drbitboy
A mistake in the program, usually caused by a bad...

A mistake in the program, usually caused by a bad assumption in the program's model of the real world.


But specifically, a loop exit condition that never becomes true.


As an example, see...
Forum: LIVE PLC Questions And Answers May 24th, 2020, 08:22 AM
Replies: 22
Views: 574
Posted By drbitboy
^^^This is a very very good idea. And if...

^^^This is a very very good idea.


And if you do it, you should add comments on the Red/Green branches stating that it has been done, again so that all logic concerning O:0/1 can be found in one...
Forum: LIVE PLC Questions And Answers May 24th, 2020, 08:14 AM
Replies: 22
Views: 574
Posted By drbitboy
This is unrelated to the First Pass issue, but...

This is unrelated to the First Pass issue, but you may want to also do something like this:



Green Red O:0/1

---+---] [---]/[---+---(L)---
on the Green branch, to handle the...
Forum: LIVE PLC Questions And Answers May 24th, 2020, 08:09 AM
Replies: 22
Views: 574
Posted By drbitboy
Expanding on what GIT wrote, I think this is what...

Expanding on what GIT wrote, I think this is what you are looking for.



Green O:0/1
-------] [---------------(L)---


Red O:0/1
---+---]...
Forum: LIVE PLC Questions And Answers May 23rd, 2020, 09:55 PM
Replies: 64
Views: 2,893
Posted By drbitboy
The CTU's built-in ONS gets reset with the CTU...

The CTU's built-in ONS gets reset with the CTU reset, which means it will think it sees another rising edge of the RTC seconds bit on the next scan. So instead of reset it is probably better to set...
Forum: LIVE PLC Questions And Answers May 23rd, 2020, 01:56 PM
Replies: 64
Views: 2,893
Posted By drbitboy
whoops, missed that, yes, of course.[/QUOTE] ...

whoops, missed that, yes, of course.[/QUOTE]


heh, we are both wrong: the reset of the 180s counter will reset .CU as well, so that counter will increment to 1 on the next scan, instead of...
Forum: LIVE PLC Questions And Answers May 23rd, 2020, 01:07 PM
Replies: 64
Views: 2,893
Posted By drbitboy
No explanation is likely without seeing the code.

No explanation is likely without seeing the code.
Forum: LIVE PLC Questions And Answers May 23rd, 2020, 01:04 PM
Replies: 5
Views: 458
Posted By drbitboy
Can you post, or send to me via PM, your text...

Can you post, or send to me via PM, your text files and a more detailed description of what you are looking for from those data? If I have time, I can usually put a prototype together fairly...
Forum: LIVE PLC Questions And Answers May 23rd, 2020, 12:56 PM
Replies: 5
Views: 458
Posted By drbitboy
A possible approach here might be to use the...

A possible approach here might be to use the Jupyter environment: basically it runs Python (or R or whatever) on a webserver-ish process, so the analysis interface is a web browser, but what is...
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 02:39 PM
Replies: 3
Views: 361
Posted By drbitboy
what are your four bit settings from table 4.8 on...

what are your four bit settings from table 4.8 on page 61 here: https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1794-um008_-en-p.pdf#G8.1048069


?
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 02:21 PM
Replies: 19
Views: 484
Posted By drbitboy
yes, modulo binary operator; if .Day is not 0...

yes, modulo binary operator; if .Day is not 0 (Sunday) or 6 (Saturday), it will be a weekday.
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 12:41 PM
Replies: 19
Views: 484
Posted By drbitboy
So there are a few choices if (.Day>0 &&...

So there are a few choices


if (.Day>0 && .Day <6)
if (!(.Day<1 || .Day>5))
if (.Day%6)
if (MOD(.Day,6)>0)

I dunno about correct syntax; I suspect the first two are faster, but as the...
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 12:35 PM
Replies: 19
Views: 484
Posted By drbitboy
Exactly.

Exactly.
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 12:30 PM
Replies: 61
Views: 2,710
Posted By drbitboy
I can't find it, but I saw an unrolled loop...

I can't find it, but I saw an unrolled loop somewhere, and the macro for the looped operation was "pew" - so the code looked summat like this (unrolled by a factor or 8):




#define pew ...

...
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 12:14 PM
Replies: 13
Views: 372
Posted By drbitboy
No, it's not. The LEDs in the link you mentioned...

No, it's not. The LEDs in the link you mentioned do not speak RS-485. There is a black box in between the LEDs and the serial server. *That* black box, whatever it is, is what needs the factory...
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 12:12 PM
Replies: 15
Views: 778
Posted By drbitboy
Wow.

Wow.
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 11:55 AM
Replies: 19
Views: 484
Posted By drbitboy
I don't know what the Red Lion day-of-week...

I don't know what the Red Lion day-of-week convention is here, but whether it's [0=Sunday to 6=Saturday] or [1=Monday to 7=Sunday], I am pretty sure this code runs seven days a week; should that be...
Showing results 1 to 25 of 500

 
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