01-18-2010 10:41 AM
I am confused with the gain setting in Tradtional DAQ (Legacy) and MAX....I am connectting SCXI 1530 to PCI 6052E.
SCXI 1530 has three gain setting 1, 10, 100.
1. For Tradational DAQ:
When writing program, "AI config" can be used to set input limits. Let's say, if I set input limits to +-100mv, will scxi 1530 automatically set its gain to 100 making output +-10V? Will input limits (+-100mv) apply to PCI 6052E or PCI 6052E will automatically change its input limits to +-10V and using its minumum gain by 1?
For example, with AI config input limits setting "+-100mv", if input signal is 50mv, will SCXI 1530 automatically choose gain setting 100 and make output 5V? Will input limits of 6052E be set automatically to +-5V and apply gain by 2? If not, how can I program both DAQ card input limits and scxi 1530 input limits?
2. For MAX,
I can set bot SCXI 1530 gain and PCI 6052E input limits.
For example, scxi 1530 gain is set to 100 and PCI input limits to +-5V, does this mean the measureable range for this channel is -+5/100 = -+50mv?
If input signal is +-50mv, does this mean scxi 1530 output will be +-5v, from MAX test panel graph should I see the signal range from -5V to 5V?
However, if gain is set to 100, PCI 6052E input limits is set to +-1V, does this mean the measureable range for this channel is -+1/100 = -+10mv?
If input signal is still +-50mv, then scxi 1530 output will be +-5V, however, PCI 6052E is using gain 10 since its input limit is set to +-1V, does this mean part of data will be lost?
01-19-2010 06:08 PM
My first suggestion would be to consider DAQmx instead of Traditional (Legacy) NI-DAQ. It completely handles all of the gain settings and makes the process transparent. Is there a reason you're choosing Traditional NI-DAQ?
Secondly, I would refer you to Chapter 3 of the Traditional (Legacy) NI-DAQ User Manual. It discusses (on page 3-19, for example) scaling of data based on whether you're using SCXI hardware. In the simplest case, you might check the One-Shot Analog Input Functions section of Chapter 3. You can access the user manual on your computer under Start » Programs » NI » NI-DAQ.