Voltage measurement through SCXI 1327

[amakthal]

Hello,

I am using a SCXI 1327 module for taking some ac voltage measurements. I have been to successfully configure it in LABView to take readings using the DAC assistant tool. Currently I am just supplying ac signals of 5V Vpp max. I understand that the module is capable of measuring upto 300V rms. 

I would like to know what changes do I need to make in the configuration of the module for higher voltage measurements.

Thanks in advance,

Ashish.

[mikealder]

The 1327 is a terminal block that acts as a front end for 1120D 1121 or 1125 measurement modules from the SCXI product range, the 1327 on its own can't make any measurements.

Inside the terminal block are a set of DIP swtches per input, these can be set to 1:1 (for low voltage measurement) or 100:1 for the higher (up to 300V measurement). When you switch them to 100:1 make sure you also make this change in MAX to the module accessory on a chanel by chanel basis otherwise you will get some very strange readings when taking measurement, MAX doesn't automatically compensate for the DIP switch positions, you have to alter this as a seperate step - Mike

[amakthal]

Thanks Mike. Will try that. 

And also, currently the max and min value that I can define in the DAC assistant tool is jus +/- 5V. Any value above that results in an error. I guess this range will increase after I make the changes you suggested.

Thanks,

Ashish,

[amakthal]

Hello Mike,

I opened up the modules and checked the jumper settings. The 1327 is set for an attenuation of 100. The jumper settings in the 1120 module were also checked. I am using channel 3. That is configured using W4 and W12. I have them on 'D' and 'A' respectively. That adds up to a gain of 1x1=1. 

But when a measure a sinusoid of 2V pk-pk I get a reading of 4V pk-pk. I also checked the 1120 and 1327 settings in the MAX tool. The individual channels have been set to the manually configured gains.

Can you help me out with it?

Thanks,

Ashish.