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Visualization Documentation – PID Block

Usage of PID Block through SCADA Template

The PID block provides Proportional–Integral–Derivative control for closed-loop automation systems.
It is used to regulate process variables (temperature, pressure, flow, etc.) by manipulating an output to maintain a desired setpoint.

Within the TPW SCADA template system, the PID block is available as a template-based graphical icon in the Visu_page.
This reusable component can be inserted into any visualization screen and linked to its corresponding logic instance for seamless process control integration.

Integrating the PID Block into Visualization steps are given below:

1. Open the Visualization Page

  • Launch your CODESYS project.
  • Navigate to the visualization screen where you want to add PID control (e.g., PID_Control, Main_HMI, etc.).

2. Insert the PID Block Icon from Scada_test Visu Page

  • Open the Visualization Toolbox Go to Current Project.
  • Drag or drop the PID Block icon to your Visualization page.
  • Or Just Copy the PID Block Icon from the Scada_test visu page and Paste into your Visualization page.

âś… This promotes visual consistency and supports template-based reuse.

Follow these steps to bind the block icon to your logic:

  • Select the PID block icon.
  • click on the block icon Properties tab open automatically → Properties.
  • Go to the References and Expand the references.
  • you will see bl_PID Expand that also.
  • set the path in front of the tagPID by Double clicking on empty space and select the required tag.
  • Build and run the project.
  • During runtime, verify that live values like PV,SV and MV functioning.

PID Block Icon – Visualization Behavior

Block Icon

Basic follwing activities can be done from the block icon- - Mode switching (Auto/Manual) - Setpoint changes - Live process monitoring

Clicking the Tagname or graphic of the PID block icon opens a faceplate:

PID Faceplate Overview

The faceplate is divided into two user-level tabs:

  1. Basic Tab – For operators
  2. Advanced Tab – For engineers or service personnel

Faceplate - Basic Tab

Block Icon

Allows basic control interactions, such as setting SP and monitoring PV/MV.
Visible to all users, including operators.

PID Parameters Details - Basic Tab

Section Parameter Description
Process Values PV Live value of the measured process variable.
SV Setpoint – target value for process control.
MV Controller output sent to actuator.
Output Limits MVLO Minimum limit for manipulated value.
MVHI Maximum limit for manipulated value.
Setpoint Control L_SP Lower engineering range limit for setpoint.
C_SP Default or central setpoint.
SPLO Setpoint runtime low override limit.
SPHI Setpoint runtime high override limit.
PV Bar PV On the left side there is PV bar which show the PV value in visual form.
SV Bar SV On the left side there is PV bar which show the SV value in visual form.
MV Bar MV On the left side there is PV bar which show the MV value in visual form.
Mode Selector Mode Select the mode of the PID By clicking on the dropdown arrow.

Operators can adjust the SP if access permissions allow.
MV is automatically calculated based on control action.

Faceplate - Advanced Tab

Block Icon

Offers engineering-level access for tuning and alarms.
Access to this tab is typically restricted via role-based login.

PID Parameters Details - Advance Tab

Section Parameter Description
Process Values PV Live value of the measured process variable.
Process Values Limit PV_LO Lower limit for the processs value.
PV_HI Higher limit for the processs value.
Alarming Limits PVLL Very low (critical) alarm.
PVLO Low warning limit for PV.
PVHI High warning limit for PV.
PVHH Very high (critical) alarm.
Tuning Parameters P Proportional gain.
I Integral time – used to eliminate steady-state error.
D Derivative time – used to anticipate error changes.
Controller Config IN_Type Input type: Linear (LIN) or Square Root (SQRT).
OP_AT Output action: Direct (DIR) or Reverse (REV).
CT_AT Control action for logic: Direct (DIR) or Reverse (REV).
Setpoint Behavior SP_TR Setpoint tracking mode enable/disable.

Adjust these settings during commissioning or maintenance under supervision.
Incorrect tuning may result in unstable control behavior.

Integration Notes

  • Always declare the PID logic block (fb_PID) in your program before linking in visualization.
  • Use access roles to restrict the Advanced tab.
  • You can enhance the block by integrating alarm banners or event logs via SCADA features.
  • Apply visibility conditions to reflect block enable/fault status.

Demo or Training Video

🎥 Watch Demo – TPW PID Block Visualization Walkthrough

This video demonstrates inserting, linking, and tuning the PID block within the TPW SCADA template.

Summary

The PID block enables precise control of process variables in a graphical and user-friendly environment.
Through its template-based integration in TPW’s HMI, it offers:

âś… Real-time monitoring and tuning
âś… Role-based access to advanced settings
âś… Drag-and-drop deployment using Visu_page
âś… Reliable interface for process stability

The PID block is ideal for operators and engineers managing continuous processes requiring accurate control.