What is a Digital Valve Controller?
Digital valve controllers, like I/P positioners, incorporate the use of an integrated I/P to operate. However, digital valve controllers, also use a microprocessor, for improved control of the valve. The microprocessor eliminates some of the mechanical components found on traditional, pneumatic positioners, like a summing beam, by comparing the input and feedback signals electronically. In this example, we can see that the electronic control signal is sent directly to the microprocessor providing an input, or setpoint. Valve position feedback is sent to the microprocessor from an electronic sensor. The input and feedback are summed against each other to determine the error. The microprocessor then calculates what output changes need to be made to correct that error. Because the DVC has a microprocessor, the DVC will typically be far more accurate than a traditional pneumatic positioner. The microprocessor also allows communication with the device. Some common communication protocols that are used are Communication allows us to interface with the digital valve controllers. Calibrations can easily be done with software programs and communicators or push buttons and menus on a local display. Information can be entered into the digital valve controller about the valve and actuator assembly. It’s then able to perform zero and span procedures automatically that typically would have been done manually on pneumatic positioners. Additional functions are available with digital valve controllers, such as improved device tuning, alerts and alarms, and even diagnostics. Well, here are some things to remember about digital valve controllers: Thanks for watching, and I’ll see you in the classroom.