Guidance on Wiring Multiple 4–20mA Sensors to NI 9203 with Limited COM Terminal Space

[waheedazam]

Hello NI Community,

I am working on connecting multiple 4–20mA sensors to the NI 9203 analog input module. My setup includes:

• 3 Air velocity sensors (each with 2 wires: yellow [+] and green [–])

• 1 Irradiance sensor

• 2 Flow rate sensors

• 2 Pressure sensors

All sensors have 2 wires: yellow (signal +) and green (common –). The NI 9203 has 8 AI channels (AI0 to AI7) and a single COM terminal for all sensor grounds.

My challenge is that I need to connect 8 green wires (sensor commons) to only one COM terminal, which has limited physical space and is designed for a single wire.

My questions:

1. What is the best and safest practice for wiring multiple sensor commons to a single COM terminal on the NI 9203?

2. Would using a terminal block or a wiring harness be recommended?

3. Are there any NI-approved accessories or adapters to facilitate this wiring?

4. Any video tutorials or documentation specifically demonstrating wiring multiple 4–20mA sensors to the NI 9203?

Thank you in advance for your guidance!

[santo_13]

If they are 4-20mA sensors, you connect the positive supply to the sensor and the other wire to 9203 and in through 9203's COM to supply's ground like below.

[AndyClegg]

How you wire them up is very much down to what you need - is it just a quick lash-up or a permanent installation in a critical application / high vibration etc and the enclosure / cable mangement being used.

Even for quick lash-up connections I prefer to use DIN-rail terminal blocks give quick and reliable connections - Pheonix Contact and Wago are well known brands - not expensive. If you're not familiar there are plenty of videos on youtube about how to use them.