Emerson Exchange 365

Terry Blevins and Mark Nixon have an article on the ControlGlobal.com website, Addressing Control Applications Using Wireless Devices. It highlights how wired and wireless transmitter installations differ in closed-loop control applications and what changes are required in the PID algorithm.

In the article, Terry and Mark conclude:

Field experience using WirelessHART in control applications may be summarized in the following manner:

• WirelessHART measurements may be used in closed-loop control applications.
  • Window communications mode minimizes power consumption
• PIDPlus is a standard feature of DeltaV and works with standard WirelessHART devices.
  • Standard DeltaV Tools support simulation and tuning
• The performance of PIDPlus in a wireless control network is comparable to PID with wired inputs.
  • PIDPlus handles lost communications better than conventional PID.
• PIDPlus tuning depends only upon process dynamics, not on wireless update rate.

For best control performance process disturbances, the guideline provided for update period should be observed. If disturbance response is not critical, then a slower update period may be used.

Do you have any experiences with wireless instrumentation used in closed-loop control?