configuring pressure transmitter WIKA A-10 to DAQ USB-6221

[mhawkin6]

I am trying to wire and configure a WIKA A-10 pressure transmitter (http://www.wika.us/upload/DS_PEA10_en_us_16479.pdf) in to a USB 6221 DAQ. I have an external power supply set at 12V for the transmitter. According to the transmitter data sheet pin 3 is the voltage signal line. I have connected the signal line to ai8 on the USB 6221. I have also connect the ai ground to the ground on the power supply. When I configure the DAQ vi for input voltage, I get something very similar to a sine wave. This does not seem right. Does anyone have any ideas?

Thanks

Mike

[BROhan]

Hi Mike,

Although it seems as if you have wired up the device correctly, I would suggest that you try to wire using a differential terminal (Sig+ to AI 0 and Sig- to AI8). Also be sure that within your programming environment you specify that you are using a differential input terminal.

[Henrik_Volkers]

Sounds like hum (due to groundloop?). The frequency is is 50/100Hz (or 60/120) ?

Is it a pure AC signal or (what I assume) a DC signal (of interest) with AC 'noise'? 

Differential configuration (as already mentioned) is the way to go.

Take a look at your 12V DC supply. How does the DC looks like? 

Message Edited by Henrik Volkers on 06-08-2010 09:08 AM