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Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 9:30 AM

Please, what could be responsible for a level controller failure to remain in cascade mode. When placed on auto mode after a while, it fails to manual mode without any human intervention.

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#1

Re: Controller fails to stay in Auto mode(Cascade), keeps reverting to manual mode.

04/24/2015 9:46 AM

Sounds like somebody does not have sound software.

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#2

Re: Controller fails to stay in Auto mode(Cascade), keeps reverting to manual mode.

04/24/2015 10:04 AM

It sounds as though human intervention is required. Is this thing a self-contained proprietary unit, Boss? If so, then a telephone call to the manufacturer would be first intervention I would make. Then, I'm funny that way.

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#3

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 11:11 AM

Whoever might know the answer would need to know the manufacturer and model, at least. Surely you have a manual available?

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#4

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 12:51 PM

I use delta V and i get this message MODBAD.

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#5
In reply to #4

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 1:08 PM

A change in velocity will have very little effect on any imaginary number. If your module is bad then fix or replace it. That is what I would do.

[Punctuation, capitalization and proper syntax is very important for precise communication.]

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#6
In reply to #4

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 2:34 PM

The "MODBAD" error in a DELTA V DCS indicates at least one module in the system is bad and requires replacement.

Be aware that there may be more than one module that has failed.

You need to go to the engineering node/terminal and drill down through the fault table to identify which modules are bad and replace all that are listed as "bad".

If you are not comfortable with performing this operation contact the DELTA V technical support for advice and follow their directions.

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#7

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 2:35 PM

Look at all the things it could be (discussion on LinkedIN)

https://www.linkedin.com/grp/post/1270757-210891384

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#11
In reply to #7

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/25/2015 3:44 AM

Thank you for the link

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#8

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 4:00 PM

Sounds like human intervention, with trouble shooting abilities, is required.

This fault can't be fixed over the internet.

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#9

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 4:39 PM

Sounds like the default mode is working correctly.

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#10

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/24/2015 7:41 PM

This could also be a simple case of ESO.

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#12

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

04/25/2015 11:33 AM

Do you have access to the signal diagram? If you do, you can bring the signal diagram up for troubleshooting purposes. It should give enough information (provided you can understand the logic blocks well enough to determine the cause). In many cases modules or level transmitters will give a Bad Quality indication which will automatically cause the unit to fail to a manual reject state. Determine if this is the case and you should also be able to determine which module or transmitter is bad quality.

What software are you using? (e.g. Emerson, etc.?)

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#13

Re: Controller Fails to Stay in Auto Mode (Cascade), Keeps Reverting to Manual Mode.

05/04/2015 7:14 AM

Hi

Seems Ur DCS controller configuration is such a way, your controller configuration enabled to Setpoint track mode. That means when ever any failure of input value from field & any interruption is communication makes the set point tracks the measured mode. Pl check for SP track option in your DCS controller configuration.

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