My setup is a 2182A nanovoltmeter and 2400 sourcemeter from Keithley performing delta measurements. I would like the source meter to output reversing current for an infinite amount of time until I tell it to stop. While the sourcemeter is triggering from + and - currents, I am using an external trigger link to to trigger the 2182A to perform a measurement at + and - and get the delta readings and store it in the 2182A's buffer.
At first I setup the parameters and do a loop of initiations within the iterations and I am getting problems. The first iteration is fine but the next iteration I am getting query errors and RSQ timeouts, even though I am resetting this bit after iteration. Also, after the first iteration, all my values get reversed, and I believe calling an :INIT in the beginning of each iteration is causing this.
Also, during the RSQ timeouts the buffer reading is all zeros, so it makes me believe the buffer is not getting written to and the RSQ bit is never set. The RSQ bit is set to when the buffer fills up (which is configured properly under the user's control).
A solution I have come with is to initiate a delta mode current (2400) for an infinite amount of pairs, and fill & empty the buffer of the 2182A. The trigger count maximum value on the 2400 is :TRIG:COUN 2500, which means 1250 pairs... that is not enough. Another solution I have thought of is resetting the :TRIG:COUN after each iteration. I tried this and was not getting past the 1st iteration because I believe that the RSQ bit is never triggering because of this.
As you see, I am having troubles for a simple concept. Infinite amount of reversing current from the 2400 and filling and emptying of the buffer on the 2182A. If anyone has input on this, I would GREATLY appreciate it.
Can you be a little more specific about the query errors you are getting? Are there any codes associated with the errors? Feel free to attach your VI for us to take a look at, there could always be a programming issue causing problems.
-- Peter R. Applications Engineer National Instruments www.ni.com/support