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Search: Posts Made By: drbitboy
Forum: LIVE PLC Questions And Answers Yesterday, 05:32 PM
Replies: 1
Views: 109
Posted By drbitboy
Can you break up the date into multiple strings,...

Can you break up the date into multiple strings, and then send the strings in sequence?
Forum: LIVE PLC Questions And Answers November 25th, 2022, 08:07 PM
Replies: 88
Views: 6,120
Posted By drbitboy
Here is the PID equation from the SLC Instruction...

Here is the PID equation from the SLC Instruction Set manual: https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1747-rm001_-en-p.pdf#G13.1041550

...
Forum: LIVE PLC Questions And Answers November 25th, 2022, 07:52 PM
Replies: 88
Views: 6,120
Posted By drbitboy
No, it does not indicate an unstable PID. ...

No, it does not indicate an unstable PID.

That behavior indicates backlash or some other form of hysteresis in the process.
_
Forum: LIVE PLC Questions And Answers November 25th, 2022, 07:51 PM
Replies: 88
Views: 6,120
Posted By drbitboy
The control output only changes due to the...

The control output only changes due to the pressure changing in the the pressure vessel. Those pressure changes might be caused by changes in the feed tank upstream of the pump, but the PID...
Forum: LIVE PLC Questions And Answers November 24th, 2022, 11:25 AM
Replies: 3
Views: 254
Posted By drbitboy
The wildcard for some SQL versions is the percent...

The wildcard for some SQL versions is the percent symbol (%).


So [WHERE ]


TEXT3 LIKE 'prefix%'

would select records where the TEXT3 character field started with the string "prefix" e.g....
Forum: LIVE PLC Questions And Answers November 22nd, 2022, 08:56 PM
Replies: 2
Views: 218
Posted By drbitboy
just the obvious: MOV to a data type with more...

just the obvious: MOV to a data type with more (enough?) bits (e.g. float or even BCD), do the add, and hope the result doesn't overflow on the MOV back to UINT.
Forum: LIVE PLC Questions And Answers November 20th, 2022, 07:39 AM
Replies: 4
Views: 580
Posted By drbitboy
https://www.edata.omron.com.au/eData/PLCs/CJ1/W394...

https://www.edata.omron.com.au/eData/PLCs/CJ1/W394-E1-16.pdf#page=310
Forum: LIVE PLC Questions And Answers November 19th, 2022, 07:14 PM
Replies: 88
Views: 6,120
Posted By drbitboy
Yes, I am well aware. But the OP has the system...

Yes, I am well aware. But the OP has the system they have, and there may be no budget for hardware. I hope the insanity of a backlash model, while simple to implement, will instead convince them to...
Forum: LIVE PLC Questions And Answers November 19th, 2022, 09:11 AM
Replies: 20
Views: 1,618
Posted By drbitboy
One of several excellent posts here on the many...

One of several excellent posts here on the many non-automation soft skills (as @Tom Jenkins calls them).

The point of education is to learn how to learn. The rest is in the noise.


For hard...
Forum: LIVE PLC Questions And Answers November 19th, 2022, 08:43 AM
Replies: 88
Views: 6,120
Posted By drbitboy
Another Hail Mary

If there is a pilot valve downstream of the current-to-pressure transducer and upstream of the oil control valve, then it might be a pneumatic valve positioner (see image below; source here...
Forum: LIVE PLC Questions And Answers November 19th, 2022, 01:22 AM
Replies: 88
Views: 6,120
Posted By drbitboy
I don't know if this approach would work in the...

I don't know if this approach would work in the field, but I created a model that takes a CV output as the input, and calculates what the actual valve position would be assuming a fixed amount of...
Forum: LIVE PLC Questions And Answers November 18th, 2022, 07:38 PM
Replies: 88
Views: 6,120
Posted By drbitboy
Is it safe to put someone at the valve with a...

Is it safe to put someone at the valve with a tape measure or ruler or yardstick? You can be watching the trend, so at the time when the CV reaches a peak or valley, and starts one of it subsequent...
Forum: LIVE PLC Questions And Answers November 18th, 2022, 01:36 PM
Replies: 8
Views: 691
Posted By drbitboy
Would it be difficult to make a test to see which...

Would it be difficult to make a test to see which it is?
Forum: LIVE PLC Questions And Answers November 17th, 2022, 04:20 PM
Replies: 19
Views: 946
Posted By drbitboy
:-/ I ran it in Do-More Designer, which...

:-/

I ran it in Do-More Designer, which seems to be similar to DirectSOFT, and something similar to what I posted does seem to work.

OT: the minimal-featured license-free DirectSOFT can select...
Forum: LIVE PLC Questions And Answers November 17th, 2022, 01:39 PM
Replies: 19
Views: 946
Posted By drbitboy
Oh dear, it is much simpler with a built-in,...

Oh dear, it is much simpler with a built-in, self-resetting DRUM instruction:


[DRUM: CT0] This DRUM instruction uses Counter CT0 (also the next three counters CT1-CT3)
[Step Preset: K1] The...
Forum: LIVE PLC Questions And Answers November 17th, 2022, 12:45 AM
Replies: 3
Views: 372
Posted By drbitboy
The process is explained in that link (click here...

The process is explained in that link (click here (https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1763-rm001_-en-p.pdf#G9.1045176)) to the Rockwell 1763-rm001 PDF...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 09:29 PM
Replies: 4
Views: 331
Posted By drbitboy
I'm not always right, but it does usually work...

I'm not always right, but it does usually work out that way :lies:.

Also,


Since there are only two pumps, the ALT_COUNT lead/lag driver has but two possible values, 0 and 1, so we can use...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 06:02 PM
Replies: 4
Views: 331
Posted By drbitboy
Here is a subset of the rungs shown in the OP,...

Here is a subset of the rungs shown in the OP, plus one more inferred.

The first image shows the case with Pump 2 failed: P1 is lead; P2 is lag; ALT_COUNT is 0.

The second image shows the case...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 05:49 PM
Replies: 4
Views: 331
Posted By drbitboy
The problem is the title of this thread; please...

The problem is the title of this thread; please burn the following statement into memory: the PLC cares not a whit what you want it to do, but it will inexorably and mercilessly do exactly what you...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 02:51 PM
Replies: 5
Views: 373
Posted By drbitboy
I would call it filtering. I have never...

I would call it filtering.


I have never worked with the list box Sysmac, so I have no idea.
Forum: LIVE PLC Questions And Answers November 16th, 2022, 02:48 PM
Replies: 3
Views: 372
Posted By drbitboy
https://literature.rockwellautomation.com/idc/grou...

https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1763-rm001_-en-p.pdf#G9.1045176

Obviously you will have your own trigger logic, but this seems to work.63616

63617
Forum: LIVE PLC Questions And Answers November 16th, 2022, 01:18 PM
Replies: 5
Views: 373
Posted By drbitboy
COUNT_OF_MATCHES := 0; FOR J:= 0 TO 199 BY 1...

COUNT_OF_MATCHES := 0;

FOR J:= 0 TO 199 BY 1 DO
IF WorkDatabase[J].Truck = DesiredTruck THEN
DB_HMI_Display[COUNT_OF_MATCHES] := WorkDatabase[j];
COUNT_OF_MATCHES :=...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 01:07 PM
Replies: 19
Views: 946
Posted By drbitboy
Here's mine. It was painful though. Is it me or...

Here's mine. It was painful though. Is it me or does every other IDE absolutely pale in comparison to RSLogix 500 for coding? It's spoiled me so bad I can't even stand RSLogix/Studio 5000.63614
Forum: LIVE PLC Questions And Answers November 16th, 2022, 10:55 AM
Replies: 5
Views: 373
Posted By drbitboy
Welcome to the forum. Your description is...

Welcome to the forum.

Your description is ambiguous; more information is needed to ensure we understand what is being asked.

First of all, it looks like you are selecting elements to display,...
Forum: LIVE PLC Questions And Answers November 16th, 2022, 07:35 AM
Replies: 19
Views: 946
Posted By drbitboy
in the Koyo/DL system, memory location V7766 is...

in the Koyo/DL system, memory location V7766 is seconds of minute, 0-59. So



LD V7766 ### Load seconds into accumulator
DIV 30 ### Divide accumulator by 30, put quotient in...
Showing results 1 to 25 of 500

 
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