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Search: Posts Made By: Mispeld
Forum: LIVE PLC Questions And Answers November 16th, 2018, 02:02 PM
Replies: 9
Views: 203
Posted By Mispeld
Your instinct is correct in that derivative...

Your instinct is correct in that derivative action will help avoid overshoot with P and I gains that result in a fast heating rate for your process. But it does have consequences such as noise...
Forum: LIVE PLC Questions And Answers November 16th, 2018, 11:57 AM
Replies: 9
Views: 203
Posted By Mispeld
Yes you are correct, that was an error in my...

Yes you are correct, that was an error in my previous post. When the dependent I factor is specified in time per repeat, as it is with Allen-Bradley PID (minutes per repeat), then a larger value...
Forum: LIVE PLC Questions And Answers November 15th, 2018, 09:11 PM
Replies: 3
Views: 101
Posted By Mispeld
This post was discussed in a recent thread, and...

This post was discussed in a recent thread, and could be a method to achieve the desired outcome.

http://www.plctalk.net/qanda/showthread.php?t=105602
Forum: LIVE PLC Questions And Answers November 15th, 2018, 01:54 PM
Replies: 9
Views: 203
Posted By Mispeld
Based on the process description, Integral action...

Based on the process description, Integral action is dominating the controller output as you re-approach set point after a tube-loading disturbance. In that scenario, as the process approaches 900,...
Forum: LIVE PLC Questions And Answers November 14th, 2018, 11:54 AM
Replies: 15
Views: 382
Posted By Mispeld
Are the 75 MSGs to different targets or all to...

Are the 75 MSGs to different targets or all to one destination? If the former, would imply the message path is in input parameter, or can be created at runtime with a parameter. I wonder if/how...
Forum: LIVE PLC Questions And Answers November 14th, 2018, 10:55 AM
Replies: 7
Views: 137
Posted By Mispeld
I will add two points: 1. Consider whether...

I will add two points:

1. Consider whether to use the LocalDateTime or DateTime Attribute in the GSV/SSV instructions. The former will interpret WALLCLOCK data with Time Zone and DST applied;...
Forum: LIVE PLC Questions And Answers November 13th, 2018, 01:54 PM
Replies: 19
Views: 597
Posted By Mispeld
It is a good question, and this basically...

It is a good question, and this basically captures it.

You can answer it this way: Are your back-ups good enough so that in the event of a failure requiring the backup, you can just reload the...
Forum: LIVE PLC Questions And Answers November 13th, 2018, 12:33 PM
Replies: 19
Views: 597
Posted By Mispeld
If the backup requirement is for the online...

If the backup requirement is for the online processor images, then Factory Talk Asset Centre/Disaster Recovery is the Rockwell product designed for this purpose. It can do most of what you are...
Forum: LIVE PLC Questions And Answers November 12th, 2018, 04:37 PM
Replies: 6
Views: 166
Posted By Mispeld
Implies the customer correctly activated it. ...

Implies the customer correctly activated it. Probably worth running FT Activation Manager to make sure.
Forum: LIVE PLC Questions And Answers November 12th, 2018, 02:23 PM
Replies: 9
Views: 285
Posted By Mispeld
Maybe best illustrated by example. If, for...

Maybe best illustrated by example. If, for example, N21:31 holds the value 147, then the bit reference would be B28/147 or B28:9/3.
Forum: LIVE PLC Questions And Answers November 9th, 2018, 08:09 AM
Replies: 18
Views: 915
Posted By Mispeld
You may want to consider level instrumentation to...

You may want to consider level instrumentation to disable the heaters if fluid level falls below the temperature sensor.
Forum: LIVE PLC Questions And Answers November 5th, 2018, 12:46 PM
Replies: 3
Views: 162
Posted By Mispeld
One issue might be Output max CV % set to zero. ...

One issue might be Output max CV % set to zero.

edit: Nevermind: Output limiting is turned off.
Forum: LIVE PLC Questions And Answers November 5th, 2018, 11:25 AM
Replies: 11
Views: 340
Posted By Mispeld
Though, this allows you to have 15 different...

Though, this allows you to have 15 different Fault and Diagnostic buttons (one pair per unique zone display), each of which could pass the appropriate zone-specific parameter to fault and diagnostic...
Forum: LIVE PLC Questions And Answers November 5th, 2018, 11:10 AM
Replies: 11
Views: 340
Posted By Mispeld
An option for 17 screens instead of 45: create...

An option for 17 screens instead of 45: create 15 unique, and almost identical zone displays. Assign each zone display a different display number, which can be monitored by the PLC. You could...
Forum: LIVE PLC Questions And Answers November 5th, 2018, 08:58 AM
Replies: 11
Views: 340
Posted By Mispeld
It's not clear how the application initially...

It's not clear how the application initially opens up an individual "zone" display (e.g., 15 different GoTo display buttons, drop-down selection, etc.). Anyway, if the processor can determine which...
Forum: LIVE PLC Questions And Answers November 2nd, 2018, 12:37 PM
Replies: 11
Views: 340
Posted By Mispeld
The following thread discusses similar...

The following thread discusses similar capability, and may offer options to accomplish what you describe.

http://www.plctalk.net/qanda/showthread.php?t=115037
Forum: LIVE PLC Questions And Answers November 1st, 2018, 11:38 AM
Replies: 11
Views: 526
Posted By Mispeld
Ot

FYI, from Wikipedia:

Marmite (/ˈmɑːrmaɪt/ MAR-myte) is a British food spread produced by Unilever. Marmite is made from yeast extract, a by-product of beer brewing. Other similar products include...
Forum: LIVE PLC Questions And Answers November 1st, 2018, 10:41 AM
Replies: 13
Views: 679
Posted By Mispeld
You may find this Allen-Bradley document helpful:...

You may find this Allen-Bradley document helpful:

Circuit Protection Methods (https://literature.rockwellautomation.com/idc/groups/literature/documents/wp/1492-wp001_-en-p.pdf)
Forum: LIVE PLC Questions And Answers November 1st, 2018, 10:31 AM
Replies: 12
Views: 790
Posted By Mispeld
Code stealers have been around for a while, such...

Code stealers have been around for a while, such as described in this article:

THIS HACKER'S TINY DEVICE UNLOCKS CARS AND OPENS GARAGES...
Forum: LIVE PLC Questions And Answers October 29th, 2018, 12:54 PM
Replies: 4
Views: 143
Posted By Mispeld
According to the Allen-Bradley documentation (see...

According to the Allen-Bradley documentation (see attached), output limiting is the last thing to happen before conversion to CV. I don't have a good explanation unless external logic is writing to...
Forum: LIVE PLC Questions And Answers October 29th, 2018, 11:57 AM
Replies: 4
Views: 143
Posted By Mispeld
Based on those screen shots, it appears that your...

Based on those screen shots, it appears that your .CV is scaled 0 to 1000, corresponding to 0 to 100% output. So a CV value of 123 will be 12.3% output of the loop.
Forum: LIVE PLC Questions And Answers October 29th, 2018, 10:52 AM
Replies: 7
Views: 161
Posted By Mispeld
In order to use CONCAT in this example, you will...

In order to use CONCAT in this example, you will need to create a one-character string to temporarily hold the individual characters being moved from the source string to your array of parsed...
Forum: LIVE PLC Questions And Answers October 29th, 2018, 09:51 AM
Replies: 7
Views: 161
Posted By Mispeld
I should also add that if you "manually"...

I should also add that if you "manually" construct a string this way (as opposed to using ASCII instructions), it is good practice to increment the .LEN element of the structure as characters are...
Forum: LIVE PLC Questions And Answers October 29th, 2018, 09:39 AM
Replies: 7
Views: 161
Posted By Mispeld
Instead of using DTOS to move from the source to...

Instead of using DTOS to move from the source to result strings, just move the individual characters (SINTs). For example, "MOV Source.DATA[3] String_Array[1].DATA[0]" to move the fourth character...
Forum: LIVE PLC Questions And Answers October 28th, 2018, 12:52 PM
Replies: 8
Views: 342
Posted By Mispeld
If you will describe your application in more...

If you will describe your application in more detail, one important question is whether the data collection and display is "station-centric" or "part-centric," by which I mean, for example: Will...
Showing results 1 to 25 of 375

 
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