Recent Control & Safety Systems Discussions
Similar Posts
FAIL Alarm on DC Block - How to prevent on Interlocks External to the Motor (ie Other Motors)
Automatically Stopping Motor with Fail Active is True
In need of some advice for Motor permissive to run & stop.
Limit Switches and start-Stop Command on MRSS_11_IP
International Wine Producer Achieves Non-Stop Control of Production Quality and Maintenance with Movicon SCADA
Share

DC Function block motor control having external non wired DeltaV start / stop locations

Hi All,

My question is regarding the DC-Device Control function block for motor control (3-wire VFD with non DeltaV integrated start / stop controls), I understand the DC operation but I am trying to figure out a special case where our operators who are not using a DeltaV workstation will turn on the motor in the field using start/stop push buttons. We do have feedback on if motor is running or not and that signal is put into the DeltaV as DC1 -> IN_1 (motor starter N.O. contact closure) .

 What happens is from the faceplate (FP) side it shows a DeltaV motor status of “Stop” from DC1->SP_D (motor is actually running) and just below that the next box shows “Running” from the DC1->FV_D (Field devices) & OUT_D = 0.

 Is there a way to momentarily pulse the FP start button in software when the IN_1=1 so as to update the DC1 module which then would put DC1->SP_D into "Running" mode and then allow the DeltaV operator to then stop the motor from DeltaV? Or should I have used a different DC motor function block or template?

ShaneG
  • Matt Stoner

    In reply to ShaneG:

    Your best method will probably be to set the DC/TRK_IN_D to True for a one module scan when the Run Status changes (actual DST value != DC/F_IN_D1 determined before DC block executes) and then set DC/TRK_IN_D back to false the next scan. Using CAS_IN will probably cause other issues as it will only work in CAS mode.

    You will never have a "failure" of the motor because it trips out unless you get some signal(s) about the field pushbuttons either directly or using Hand Off Auto (HOA) type signal to trigger the TRK_IN_D when field buttons "could" be pressed (HOA is not in AUTO).

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.