High Country Tek DVC80 - Manual (Page 67)

P/N: 021-00154, Rev. A.6 - updated for V4.7 Tools Page | 67
Loader/Monitor window and the following screens should be visible. Note also the changing Dig_1 to Dig_3
LEDs on the DVC5/10 module.
You have completed Example 2 and now we will introduce you to more sophisticated control applications.
5.4 Process PI Closed Loop Control Example (PSI to Valve Current)
Process PI is a capability of the DVC that makes it
easy to control a valve’s current as a function of
another sensors input. The example demonstrated
here is a valve that controls the flow through a
hydraulic pump that in turn generates pressure in a
line. A pressure sensor provides the feedback that is
used to adjust the valve current and therefore the
flow to the pump to achieve a desired pressure or
setpoint.
The screens shown demonstrate how easy this is to
achieve with the DVC. In this example the Setpoint
or desired pressure is inputted to the DVC5 controller
by the voltage reading from an analog signal or
potentiometer. The 0 to 5v signal represents a
pressure range of 0 to 5000 psi. The feedback signal or pressure achieved by the pump is inputted to the DVC5
via a second analog signal of 0-5 volts with 5 volts representing a maximum of 5000 psi.
The first 5 lines of the Always code do all of the work.
' *** Control Code ***
Valve_1.enable = SetPoint_PSI
Valve_1.Setpoint = SetPoint_PSI Valve_1.Feedback = FeedBack_PSI