Wireless transmitters may be preferred in applications where new measurements are required since the cost may be lower than that associated with installing wired transmitters. However, there is a significant differences in the frequency and manner in which a new measurement value is updated by a wired transmitter vs. a wireless transmitter. Such differences must be taken into account when a wireless measurement is used in closed-loop control. Earlier this year, Marty Zielinski and I wrote a paper Using Wireless Measurements in Control Applications that address how the PID can be modified to effectively address control applications using wireless devices. At ISA Automation Week on November 7th, 2014, we presented this paper in a session on Secure Wireless Control & Risks. In the paper we show the differences between this modified PID, known as the PIDPlus, and the traditional PID. Also, test and field test results are presented that show that the same quality control as wired PID can be provided by PIDPlus despite slower, non-periodic wireless measurement update and communication interruptions. The picture below shows Marty Zielinski during the paper presentation.
The presentation is approximately 26 minutes in length:
- 0-1 Introduction
- 1-4 The Challenge in Using Wireless Measurements in Control
- 8-13 Modifying the PID for Wireless Control (PIDPlus)
- 13-18 Test Results
- 18-20 Field Trial Results
- 20- 21 Summary, Leaning More
- 21-26 Question/Answers
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