Recent Control & Safety Systems Discussions
Similar Posts
PID Function Block behaviour in MAN mode
block valve going into hold when in cas
Download Behaviour for Redundant controllers 13.3
Cold Restart - Controller Behaviour on Startup
safety functionality to detect if a manual valve is open or closed
Share

Analog Tracking Function Block, Hold in Manual Behaviour

I have the Analog tracking block (AT) connected to PID track input. PID track is enabled. I have a tracking condition that puts the controller in manual.

Books Online States:

Hold in Manual for control loop modules

When any tracking condition's T_L_OUT_Dnand T_HOLD_MANn parameters are True, the mode of the target analog block wired to OUT_D is set to Manual.

 

But when I check the Hold in Manual Block. Upon activation of tracking condition, The PID Mode goes from Auto/Auto to Auto/Local Override instead of Manual. 

In control options, Tracking is enabled and Track in Manual is disabled. Even if I enable both the issue remains.

Any Suggestions?

Thanks

Anupam_C
  • Trista VanDerVeeken
    Hi Anupam,

    I created a test module with the parameters for control opts and T_HOLD_MAN1 set up the same way you have described and when I trigger the interlock expression, the PID does go into manual with an out of 0 (this is what I have set as T_VAL1 ) but I am able to manipulate the output if I would like. With the expression still triggered, I am also able to change the target mode from manual to auto. I then see the mode go to Auto/Local Override and I am unable to manipulate the output. If I change my target mode back to Manual then both target and actual are manual and I am able to manipulate the output again.

    Do you have something in your logic setting the target mode of that loop to auto? If you have more than one expression being used, can you ensure you have set the proper T_HOLD_MANn to True?

This is the official online community site of the Emerson Global Users Exchange, a forum for the free exchange of non-proprietary information among the global user community of all Emerson Automation Solution's products and services. Our goal is to improve the efficiency and use of automation systems and solutions employed at members’ facilities by sharing our knowledge, experiences, and application information.

User Groups | World Areas | Community Guidelines | Legal Information | Privacy Policy | Contact Community Manager

Website translation provided by Website Translator

© 2015-2022 Emerson Global Users Exchange. All rights reserved.