SCXI

[billow.j]

Q1: How to get right result at high sample rate with SCXI-1102?

My signal acquire system include:
PXI-1011 mainframe;
PXI-8176 (PIII 1.2G 256MB sdram ) controller;
PXI-6052E 333Ksa/s daq card;
SCXI-1102;
SCXI-1303;
K-type thermocouple;
LabView 6.1;
NI-DAQ 6.9.3..

I want to sample 25 channels together. When sample is set rate as 2Ksa/s, system returns right result. But when I raise sample rate such as 5Ksa/s, system return incorrect values.

I use another system built with DAQCard-6024E, SCXI-1001 SCXI 12 slot chassis and the same SCXI-1102 module. The system works correctly.

How can I get correct result?

Q2:

I want to insert SCXI-1102 programmatically in the program. I often need to change SCXI modules. But now only in the NI MAX could do
it. Is it possible to do this programmatically?

[RIO-Todd]

Q1
Are you using bias resistors? You can run into problems when using a floating source in differential mode without using bias resistors. The SCXI-1303 actually has resistor packs that allow you to easily add bias resistors. I would make sure you have those resistor packs installed. The user manual linked below goes over installing the resistor packs.

SCXI-1303 User Manual
http://digital.ni.com/manuals.nsf/webAdvsearch/9DA3B7D5C7F572F986256694004DEFE6?OpenDocument

Q2
Unfortunately, there isn't a way to programmatically add SCXI modules. There is an "auto-detect" feature within MAX that allows for an automatic detection of SCXI modules. You will have to be in MAX in order to add modules.

I hope this helps.

Regards,

Todd D.