SCXI-1125 & PXI-6289

[test_engineer]

Dennis_Knutson,

I set my signal as min 0V & max 0.5mV; not +/-5

All of NI hardware captured samples from my pulse train will be below 0.5mV.  0.5mV is the MAX that I will ever see from my signal.

I need to know the signal voltage levels at each of hardware (1327, 1125, & 6289) so I can calculate the AARTI (absolute accuracy relative to inputs.)

[Dennis_Knutson]

All this time you've been asking about the gain of the SCSI. Don't you understand that all of these gain settings set the output of the SCSI to a max of +/- 5 volts. Take the x2000 setting that you've been harping about and think what you would get with the max signal of 2.5mv. Does not that say that the signal range out the SCSI is going to be +/- 5 volts? Is this not the voltage range that the 6289 is going to set itself to? You've been told over and over again that the gain is not set by anything you actually measure.

[test_engineer]

Dennis_Knutson,

I think now i have everything put together.

I can see now you have been trying to explain to me the same idea that I had originally.

I did make a mistake by saying multipling 2000 to 0.5mV & "So 6289 will select +/-1V normal range" in my inital post.  It should have been 2000 * 2.5mV & +/-5V.  (a lot of typing and transferring text between WORD and NI forum has messed up my thinking)

Your later post "Neither. It would be the +/- 5mv." completely threw me off the track.  And you said "You've set the SCSI to output a max of +/- 5." without any explaination how you got the number even confused me more.  (sorry i could not understand the calculation thta you had in your mind)

I have to give credits to Eric, and his post made me undertstand my thoughts were correct and you have been trying to explain the exactly same thing to me.

I see i made you frustrated in the last post.  sorry about that.

one comment: if you could clearly point out my mistake with numbers as Eric did, I should have picked it up early on.  (again it's my deficiency that I could not tie your words with numbers) (i am one of examples of people with bad communication skills)

Appreciate both of you for help, and best regards.

[Dennis_Knutson]

Sorry about the neither post. As I said, I missed your decimal point and thought you said +/- 5mv.