How can I fix the different action between two equipment?

[KUB]

Hello!

I use two equipment (Keithley 2400 and Hp 34401A). However, I have one problem as follows.

1) I set up the trigger time of Keithley 2400 as "1s". To measure some vale by Hp 34401A, I set up "Wait until Next ms Multiple" as "1000ms".

2) However, Keithley 2400 acts exactly with the trigger time, but HP 34401A do not act with 1000ms.

How can I fix this problem?

Thank you!

[Shawn B.]

KUB,

I looked at your VI, and it appears the only connection between your HP 34401A and the Keithley 2400 is the "Number of Points" Control. So unless there is some external connection between these devices I don't see why the HP 34401A would sample every 1s. If you want it to sample every 1s you could add a 1000ms Wait to the while loop.

Shawn B.
National Instruments

[KUB]

Thank you for you response!

Even though I put "The wait until next ms multiple" (1000ms) in the loop of HP 34401A, HP 34401A does not measure per 1000ms. This measures per a little longer time than 1000ms.

For example,

1) I set up the number of points (100)
2) I expect the total time that HP 34401A will take: 100(The number of points)*1000ms=10000ms
3) In reality, HP 34401A takes a longer time than I expect like about 15000ms

How can I fix it?

[Shawn B.]

Each iteration of the loop may take slightly longer than 1s because we don't really know exactly when the millisecond timer will start. If you need higher accuracy you may want to use a Timed Loop instead of the While loop with the millisecond timer.

Shawn B.
National Instruments