PID Loop Tuning Technology
LOOP-PRO transforms your everyday process data into optimal PID control.
LOOP-PRO stands apart in terms of the data that can be used to successfully tune PID control loops. Like other tuning packages, LOOP-PRO needs data that contains information specific to the control loop being tuned, including the Process Variable, Controller Output as well as the corresponding Time Stamp. Relative to other tools, that’s where the similarities end. Unlike other tuning packages, LOOP-PRO can accurately model complex processes using data that is both noisy and oscillatory. That’s real-world data. That’s the LOOP-PRO difference.
The process data requirements for tuning software are based on some general rules of thumb. When tuning PIDs it’s helpful to keep the following guidelines in mind:
- DLO: Data should be collected around the Design Level of Operation (DLO) to assure that tuning parameters are best suited for a loop’s normal range of operation.
- Sample Rate: Data should be collected at speeds fast enough to reveal the loop’s true dynamics and to avoid aliasing. Data that is at least five (5) times the process Time Constant or three (3) times faster than the process Dead-Time are good rules of thumb.
- Noise Band: Step test data should force the Process Variable outside any associated noise in the process. A rule of thumb is to perform tests that are at least four (4) times the noise band.
Fortunately, LOOP-PRO has built-in heuristics that alert users when the process data exhibits limitations. The following details offer additional insight into LOOP-PRO’s capabilities.
Online vs. Offline
LOOP-PRO supports both online and offline data connectivity. For live connections LOOP-PRO utilizes OPC. LOOP-PRO’s DirectConnect feature automatically captures essential process data and identifies controller-specific attributes such as the associated algorithm and controller spans. Using the software’s deep scan function LOOP-PRO locates all PID loops on your control network with the touch of a button. Once a loop is selected for analysis and tuning, LOOP-PRO automatically uploads the relevant and controller-specific details. OPC Direct Access can be used to connect live to controllers.
LOOP-PRO’s offline analysis and tuning capabilities are equally effective, and they’re ideal for users that are on the go. The software accepts any flat text file format including XLS and CSV. Different process data components such as Process Variable and Controller Output are easily categorized for modeling and tuning. LOOP-PRO’s library of algorithms is extensive and supports the controllers of all major PLC and DCS systems.
Whether you’re connected live to the process or reviewing historical data files, LOOP-PRO makes it easy to tune PID controllers for improved performance.
Open-Loop vs. Closed-Loop
From LOOP-PRO’s perspective: Good data is good data. LOOP-PRO was designed to accurately model good process data resulting from either closed-loop Set Point changes or manual changes of the Controller Output. It works equally well with the data you have, making LOOP-PRO an ideal controller tuning and process optimization solution.
Controller algorithms generally involve higher order math and can be complex. They represent one more possible stumbling block between you and optimized PID control. A simple miscalculation can have far reaching implications. With LOOP-PRO, that’ll be one less thing for you to worry about.
LOOP-PRO supports the PID algorithms of all major PLC and DCS systems along with the algorithms of many lesser known brands. If connecting live to the process, then LOOP-PRO will automatically identify the controller and associated algorithm. If you’re working offline and using historical data, then LOOP-PRO makes it easy to select the right algorithm. It’s as easy as point and click. Model parameters are converted automatically into the tuning coefficients needed by your controller. Among the many brands of controllers supported by LOOP-PRO are the following:
- Automation Direct
- Emerson Electric
- GE Fanuc
- Johnson Controls
- Metso Automation
- National Instruments
- Opto 22
- Rockwell Automation
- Schneider Electric
And many more.