Recent Control & Safety Systems Discussions
Similar Posts
Derivation of DeltaV PID Algorithm
PID Algorithm ISA Technical Reference
Delta V discrete PID algorithm (z-transform)
AO block without AUTO option
Error Gap Algorithm for Level Control
Share

PID block without algorithm

Hello to all,

I need to use a PID block to display the input and output of a PID running in a PLC, i.e. I need to create a PID in DeltaV without running the algorithm.

It may seem strange, but this is necessary so that the operators don't notice the difference even though the PID algorithm is not in DeltaV.

Thank you very much.

Best Regards,

RAguilar
  • Steve Ward
    This might be posted to the wrong forum.

    Generally in a DCS if you want to see the PID faceplate then yes to need to configure a PID block. If you don't need the PID faceplate then you might prefer to use indication blocks and an analogue setpoint for the setpoint value.
  • Inocencio Perez
    As said: you can go with analogue blocks...or if you want to use same faceplate and block you can bypass the PID...
  • Andre Dicaire
    This is a common requirement, but how should this be done? I see this as a SCADA application, where the control function in the PLC is abstracted up to the DCS HMI to allow the Operator to take direct action. The PLC control parameters are mapped to an EIOC or a Deltav controller IO subsystem. All that is really needed is a module with a collection of External references that allow an Operator to write Setpoint, Mode, OUT and to display PV.

    But to have this line up with the existing HMI objects like the Faceplate, or Detail display or graphic Dynamos/GEMs, these parameters need to be applied in a similar structure. So a Composite block can be built that hosts these various parameters to create the matching paths, such as /PID1/PV, PID1/SP etc. When viewed in Control Stuido, the module will look the same as a native PID block.

    The requirement is to create this Composite block with all the parameters that the HMI object looks for. The Faceplate links via the Module and the PID1 block, and the Alarms. DeltaV has many parameters in a PID block, but most are not directly referenced in the Faceplate or graphics. A review of the Faceplate should provide the list you need.

    I would create a separate Detail display for PLC Based control functions so you don't have to try and force the data from the PLC into the exact same structure for all the tuning values. but you can use the same Faceplate and Gems by creating the Composite and naming it PID1.

    For alarms, I would add an ALM block and manage the alarms in the DCS off the PV. If your alarm system is in the DCS, mapping alarm bits and trip limits from the PLC add to the data exchange, but the alarm time stampl will be set by the DeltaV module. the Alarm system is really a separate tool from the control and will be just as effective if applied at the DeltaV module level, with easier management in one system and reduce data exchange required. Interlocks in the PLC are different, but alarms, once created in the module following the DeltaV alarm guidelines, will work in the faceplate and graphics.

    Andre Dicaire

  • RAguilar

    In reply to Andre Dicaire:

    Dear Andre,

    Thank you very much for your reply.

    Could you provide me with an example image? Please do

    Thank you very much and best regards,

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.