Hi, I'm trying to control a pump through fieldpoint using Labview. The pump uses an "FMI Stroke Rate Controller" that has a 4-20mA input to regulate the flow. The 4-20mA input has a positive and negative terminal but I don't know how to actually connect this into my cFP-AO-200 module. I'm aware that each channel has an output terminal, a common terminal (COM), and a supply terminal (Vsup) but which wires are suppose to connect with what? Can anyone please help me with connecting it? thanks
You will need to wire an external power supply to the V & C terminals of the cFP-AO-200. The power supply positive should be wired to V and the negative to C. The power supply should be between 5 and 30 VDC. The input impedance of the pump will determine the minimum voltage that the power supply must be. The formula is Vmin=3+0.021*Resistance.
The 4-20mA positive pump input should be wired to the Iout terminal of the cFP-AO-200. The 4-20mA negative pump input should be wired to one of the COM lines of the cFP-AO-200.
One question though. The stroke rate controller that I am using (the device with the 4-20mA input) has a 110 V (50/60 Hz) input that can be plugged into an outlet so that it can run manually. So does that still mean I will need to wire an external power supply or should I somehow manipulate that 110 V input?