how do i set input limits for my PCI-6110?

[mukesh]

hi,

i have a PCI 6110 device. i need to measure appx 15V on channel 1. however my "DAQ_DB_Transfer" seems to measure only 9.9V. i realized that this is the same value that i get in MAX software when "high input limit" is set to 10V. i notice that in the MAX software when i change it from default 10 V to 20 V i get the right reading i.e. 15V. but i need to do this in software from my program in VC++. what would be the Ni-DAQ function to use for changing the input limits?

i tried "AI_Configure(1,1,0,20,0,0)" but nothing seems to happen. i doubt if this is the function to use. what would be the right call that i would have to make?

thanks in advance,
mukesh

[Russell]

I can see how you could misunderstand the role of the "Input Range" parameter of the AI_Configure() function. Especially with the way things are done in MAX. AI_Configure is responsible for setting the input mode and whether the input will be polar/bipolar. The "Input Range" parameter is actually ignored for most boards. Various ranges are obtained by changing the input gain to the card. Each card will have a different set of gains to choose from. You set this gain using either the AI_Setup() or SCAN_Setup() functions depending on whether you are sampling one channel or multiple. When you change the Input Limits in MAX, it chooses the gain that is the closest fit to the limits you enter.

I hope this clears things up. You might also look at some of the
example programs in your NI-DAQ folder for reference.