How to Connect a Loop-Powered Current Transducer Using NI 9207

Updated Mar 6, 2019

Reported In

Hardware

  • NI-9207

Issue Details

I would like to use NI 9207 to measure the current of a 2-wire transducer. I don't know how I connect transducer with NI 9207.

Solution

Typically, a 2-wire current transducer is powered by an external power supply and outputs a pressure signal as a current signal. Therefore, it is necessary to configure the connection to supply additional DC voltage. 

Before the measurement, you must connect an external power supply with a 0 to 30 V voltage range to the NI 9207. This power supply provides the current for the transducer you connect to the module. 
Caution: Do not remove or insert modules if the external power supply connected to the Vsup and COM pins is powered on

The connection sequence is as follows:
1. Connect the positive signal of the external power supply to the Vsup terminal of the NI 9207
2. Connect the negative signal of the external power supply to the COM terminal of the NI 9207
3. Connect the positive signal of the current transducer to another Vsup terminal of the NI 9207
4. Connect the negative signal of the current transducer to the AI8 channel terminal of the NI 9207(The channel used by 9207 for current measurement is AI8 ~ AI15. You can use it by selecting a channel.) 
Please refer to the figure below.