Greetings
Im currently attempting to convert from an old Field Point system to a newer cDAQ-9188. What I thought would be fairley straightfoward has become some what complicated as the 2 systems were not very similar. The first hurdle I have come accross is connecting 3 seperate pressure transducers to the 9207 module. The transducers have four wire comng from the rear of the unit. (PWR in, Signal High, Signal Low and Ground). they were connected to the AI-110 as follows:
Sensor -> AI-110
Pwr in -> Vsup
Signal High -> Vin
Signal low and Ground (tied together) -> COM
The transducer outputs a 0-10V and needs a 18-35VDC power source. The old Field point unit supplied this through a power rail common to all the modules in the system. It appears that the CDAQ unit does not do this as the documnetation for the 9207 says you can connect a powersupply to power devices connected to it. Im very hesitant to connect the power supply directly to the 9207 as I am afraid it will be to much for it to handle. ( I have three of these transducers to ultimaltley connect to the unit) My idea was to connect the power supply to a seperateterminal block and connect the PWRin and Ground from the transducers to the + and - of the powersupply respectivley. Then connect the signal high and signal low wires to the AIO+ and AIO- terminals on the 9207.
This would be fine however all the documentation I have seen regarding this connection shows the COM terminal on the 9207 also being used and tied into either the ground from the powersupply or the the ground from the transducer. I dont know electrical systems like this enough to feel comfortable that I wont fry one of these modules just trying it. Any suggestions would be greatly appreciated.
