PB with making "fast" DC measure with HP34401A .... : 400 ms

[marc france]

Hello,

I have already posted this problem a few days ago but I still haven't found any solution to it... I need to make  DC voltage measures with an HP 34401A Multimeter. I can't figure out how to get it to take measures( only one  (or more) ) quicker than every 400ms.... I would need it to be every 100 ms at least.  I have attached one of the programs ( which is infact one the examples taken from the example library ) that I can't make run faster than what I have just explained ...

I have tried the other examples.... but can't get one DC measure quicker than every 200 ms....

I am using XP and Lab 7.1.

Thanks for your help,

Marc

[johnsold]

Marc,

If I read the program correctly, you are not going to do much better than that. The Fetch (Output Buffer).vi asks for 10 samples at 16 bytes per sample. At 9600 baud and 11 bits per character, it takes more than 180 ms to return the data. This does not include time to send commands to the instrument or for the instrument to respond.

I do not know this instrument, but check to see if it has a binary or simplified data format which requires fewer characters per sample. If you can get down to 5-6 characters per sample that alone will give almost a three to one speed up. Higher baud rates, if possible, would help also. You will probably need to use something other than the default setup for the instrument to get this performance.

Lynn

[marc france]

Hi Lynn,

Thanks for your answer. I am now trying to see if it's possible to use my 6221 E card to make this kind of measurement. Infact, I wanted to use that multimeter because I need to  make a four wire resistance measure ( In my post I was talking about a DC measure to simplefy the problem ).

Id