You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > Search Forums

Showing results 1 to 25 of 500
Search took 1.11 seconds.
Search: Posts Made By: danw
Forum: LIVE PLC Questions And Answers Yesterday, 08:04 AM
Replies: 8
Views: 185
Posted By danw
Not true. Instrumentation in a hazardous area...

Not true. Instrumentation in a hazardous area has to be rated for the hazardous area and installed as hazardous area equipment.

4-20mA is low power, but that in and of itself does not eliminate...
Forum: LIVE PLC Questions And Answers April 16th, 2018, 06:30 PM
Replies: 26
Views: 944
Posted By danw
shield grounds on the rack right at the I/O...

shield grounds on the rack right at the I/O modules on one PAC I work on:

https://s7.postimg.cc/kiiud0bhn/Shield_ground_connections.jpg
Forum: LIVE PLC Questions And Answers April 16th, 2018, 04:42 PM
Replies: 9
Views: 244
Posted By danw
No. The issue is not the maximum current, the...

No. The issue is not the maximum current, the issue is how much resistance 24V can drive in the circuit.

The Siemens transmitter drops some voltage for operational purposes and can drive current...
Forum: LIVE PLC Questions And Answers April 12th, 2018, 01:30 PM
Replies: 27
Views: 1,109
Posted By danw
I have NEVER seen a manufacturer publish a spec...

I have NEVER seen a manufacturer publish a spec for response time to a poll. The response time of a slave is what it is.

Part of the issue (in publishing a spec) might be defining what...
Forum: LIVE PLC Questions And Answers April 9th, 2018, 04:34 PM
Replies: 27
Views: 1,109
Posted By danw
The issue is not the need for repeater action, as...

The issue is not the need for repeater action, as much as it is for isolation from a ground loop that can vary over time and also for biasing. Some isolators have biasing built-in.

There's an app...
Forum: LIVE PLC Questions And Answers April 9th, 2018, 04:09 PM
Replies: 27
Views: 1,109
Posted By danw
My experience as well. I concur.

My experience as well.
I concur.
Forum: LIVE PLC Questions And Answers April 6th, 2018, 09:10 PM
Replies: 27
Views: 1,109
Posted By danw
1. Is there a signal ground wire as well as the...

1. Is there a signal ground wire as well as the A/B driver lines? Not a shield, but a 3rd signal ground wire?

2. The polling rate of the master on a multidrop daisy chain with many slaves can...
Forum: LIVE PLC Questions And Answers April 3rd, 2018, 10:15 AM
Replies: 12
Views: 446
Posted By danw
+ for GaryS. Just make sure your...

+ for GaryS.

Just make sure your slightly-out-of-tolerance 3.96mA is within the non-fault 0-20mA signal range.
Forum: LIVE PLC Questions And Answers April 3rd, 2018, 10:13 AM
Replies: 7
Views: 422
Posted By danw
Analog outputs tend to be DC power higs and they...

Analog outputs tend to be DC power higs and they dissipate a lot of heat, so the number of AO’s is frequently limited due to heat dissipation and available DC power. But that’s a spec by the...
Forum: LIVE PLC Questions And Answers March 31st, 2018, 10:27 AM
Replies: 4
Views: 268
Posted By danw
The problem is a pressure value at the AI that is...

The problem is a pressure value at the AI that is different than the pressure value at the transmitter.

That could be misconfiguration of the AI, but
you replaced the transmitter and...
Forum: LIVE PLC Questions And Answers March 30th, 2018, 05:24 PM
Replies: 4
Views: 268
Posted By danw
>I mean can anyone show me what is the root cause...

>I mean can anyone show me what is the root cause of this problem...

Probably not. It would require a forensic investigation of the bad transmitter, something that only manufacturers are...
Forum: LIVE PLC Questions And Answers March 30th, 2018, 07:05 AM
Replies: 17
Views: 787
Posted By danw
Does the AI card save all 20 samples and then...

Does the AI card save all 20 samples and then transfer those 20 samples to the PLC at 1mS intervals?
Forum: LIVE PLC Questions And Answers March 28th, 2018, 09:56 AM
Replies: 2
Views: 120
Posted By danw
Both Sense and E&H have a temperature transmitter...

Both Sense and E&H have a temperature transmitter with the same model TMT-192. It might be the same, it might not.

Both are 2 wire, loop powered temperature transmitters. Both are HART.

In...
Forum: LIVE PLC Questions And Answers March 18th, 2018, 01:42 PM
Replies: 6
Views: 293
Posted By danw
Modbus TCP vs UDP; Modbus TCP vs RTU over RS-485

1. Modbus TCP vs Modbus UDP
There is recent mention of Modbus UDP (Modbus over ethernet, but UDP, not TCP) on this thread.

http://www.plctalk.net/qanda/showthread.php?p=772283#post772283

I...
Forum: LIVE PLC Questions And Answers March 18th, 2018, 01:23 PM
Replies: 14
Views: 667
Posted By danw
I'm going to start a new topic because I see...

I'm going to start a new topic because I see differences in RTU vs TCP for the hardware layer implementation and I'm curious as to who implements Modbus UDT and whether it is as 'reliable' as...
Forum: LIVE PLC Questions And Answers March 16th, 2018, 05:11 PM
Replies: 12
Views: 416
Posted By danw
Your alternative server/slave, Scadapack,...

Your alternative server/slave, Scadapack, provides a valid Modbus/TCP response and does not throw an error/fault.

Given that the Scadapack reply message format is different from the Data-linc...
Forum: LIVE PLC Questions And Answers March 9th, 2018, 01:27 PM
Replies: 11
Views: 507
Posted By danw
https://ibb.co/hhkhXnHere's a couple diagrams for...

https://ibb.co/hhkhXnHere's a couple diagrams for insertion into a Pipe Tee.

Substitute a real RTD head for the conduit 4x4 box and you'll get the picture.

https://ibb.co/diPFk7
...
Forum: LIVE PLC Questions And Answers March 9th, 2018, 10:47 AM
Replies: 11
Views: 507
Posted By danw
Temperature sensors come in different styles -...

Temperature sensors come in different styles
- 'clamp-on'
- 'free-standing'
- inserted into a thermowell

Industrial temp sensors are typically RTD or thermocouple.

A temperature...
Forum: LIVE PLC Questions And Answers March 8th, 2018, 06:31 PM
Replies: 7
Views: 375
Posted By danw
I would have concerns about either module...

I would have concerns about either module creating a standing wave which reflects energy back that creates false bits because I see either as more of a star topology where each RJ connector is the...
Forum: LIVE PLC Questions And Answers March 7th, 2018, 01:35 PM
Replies: 18
Views: 470
Posted By danw
raw/proportional what? Which units?

raw/proportional what? Which units?
Forum: LIVE PLC Questions And Answers March 6th, 2018, 06:58 PM
Replies: 2
Views: 191
Posted By danw
Near perfect for RS-485: - third wire for...

Near perfect for RS-485:
- third wire for signal ground
- 120 ohm impedance, easy to terminate with common 120 ohm resistors
- super shielding - braid and foil

The shielding and twisted pair...
Forum: LIVE PLC Questions And Answers March 3rd, 2018, 08:24 AM
Replies: 16
Views: 904
Posted By danw
The Honeywell is not a fit. It has specific...

The Honeywell is not a fit. It has specific record generation functions but not quite to the extent needed for everaging daily totals.

Some other comments on the task:

Accuracy:
The most...
Forum: LIVE PLC Questions And Answers March 2nd, 2018, 10:04 PM
Replies: 16
Views: 904
Posted By danw
I think a stand-alone Honeywell paperless...

I think a stand-alone Honeywell paperless recorder could do this. It might be a collection of .rtf report files generated/issued daily for the daily max and average flow rates (prints out as a...
Forum: LIVE PLC Questions And Answers February 27th, 2018, 10:17 AM
Replies: 15
Views: 698
Posted By danw
It makes ultimate sense. 1.00 ounces has twice...

It makes ultimate sense. 1.00 ounces has twice as many ions as 0.50 ounces.

Conductivity is measurement of how many conductive ions are available to conduct an electrical current. More ions,...
Forum: LIVE PLC Questions And Answers February 24th, 2018, 10:22 AM
Replies: 6
Views: 435
Posted By danw
1. First link comes up as a video, not a wiring...

1. First link comes up as a video, not a wiring diagram.

2. Why do you see a need to power all nine valves from you PLC? Why not use an external DC power supply?
Showing results 1 to 25 of 500

 
Forum Jump

All times are GMT -5. The time now is 02:04 PM.


.