04-01-2023 04:40 AM
Select NI9232 as a Voltage acquisition device and Connect with cDAQ9174.
There is a input at Board1/ai0 9V 1600Hz, cDAQ9174 measure ai0 correct. ai1 and ai2 are very small number about 0.0012. They are correct
Once connect a multimeter with ai1 or ai2, the voltage display 0.3v-0.4v.
What is the reason of that , this is affact the test. and is NI9232 a suitable board to test voltage?
Thnks
04-01-2023 08:03 AM
Depends a lot of what generates the signal and how you measured using the DAQ and what DMM.
04-06-2023 12:36 AM
I use NI-Max measure it.
As below ai1 do not connect input , but once the ai0 input is power on, ai1 will measure 2-3v
I will try to connect resistance on input.
Could you share some cases cause this scenario. Thank you
------ ai0 +
AC 9V 2200hz
-------ai0 -
---- ai1 +
---- ai1 -
04-06-2023 11:21 AM
You still did not explain where your signal comes from.
04-06-2023 01:56 PM
The NI 9232 is not a generic AI module - it comes under Sound and Vibration - so it is more aimed at measuring high frequency AC signals, coming from vibration sensors (TEDS, IEPE and non‑IEPE). So whilst it can be used to measure normal analogue voltages, you may need to configure it so that it can cope with the type of sensor/source you have connected. Such as ahings like the sample rate, filtering, DC or AC coupling - see the Getting Started guide.
It may be that you have some voltage level issues, depending if your sensor is floating or grounded. There is a good White Paper on ni.com called Field Wiring Guide and that is a good introduction to things like grounded/floating inputs, single ended / differential inputs. Most of it is about noise, which you may not have (yet).
05-22-2023 11:03 PM
There is a driver output 9v 2200Hz sine signal parallel connect to Ai0+, Ai0-, and connect to the device to test as power supply.
Thank you
05-22-2023 11:22 PM
hi
Thank you for your reply. There is some update for this issue
The input signal is 9v sine single and it is differential signal. I change it(Ai0) to single-ended then Ai1(differential signal) will be stable.
But Ai1 measured result is not accurate, deviation getting large.
And I need to keep Ai0 as a differential signal.