measurement time and openness 4132

Hello

I use a 4132 SMU with a switch 2531 to measure different resistance in an electric circuit. I use a brief biphasic pulse of 50ms ~ to measure resistance. My problem is the measurement time if long - it seems that the minimum pulse width I can do is a 30ms pulse in a polarity and a pulse ~ 40ms in the other polarity. I disabled 'way' that knocked 20ms on each phase, but I am still left with a ~ 70-80ms measure, but I wish it were half that, if possible. The only other way I can see to minimize the measurement time is at the bottom of the window opening, but any if I increase or decrease the time of opening, the measure takes about 10 x longer if the opening is none other than 1 PLC.

Attached is the Subvi I use to measure the unique resistance value. Note that first I close the relay to solve part of the circuit and then configure the SMU and then get several measures, one for V (+) and one for the (-) V. This measure will be repeated 15 times in quick, although succession with different closed relay, which means that the SMU gets reconfigured/initialized 15 times with the same parameters, so maybe that's my problem. I have not ventured into the handshake, but I would like to know if there is anything else I can do since the handshaking deal would take a lot of programming. In any case, when I run the VI several times, there are only 8 ms between biphasic pulses, so the reconfiguration may not take THAT long.

I posted a jpg file of the time trace of the impulse it generates (10,000 samples per second). Note that the first phase of the pulse is a different length of time that the second phase: there is nothing in the program that would cause - it would be more logical if the first phase was more time on behalf of increasing the time for the configuration of the SMU. So I have sort of a bunch of problems here: 1) cannot reduce opening time 2) want to avoid a handshake VI if it means hours and hours of programming, 3) uneven pulses. I hope someone can point me in the right direction!

Thank you very much

GimNPC

gimNPC,

As mentioned earlier, you should not call Reset every time at the end of the method. Instead, set the output to 0 c. Moreover, all the attributes that are not changed will not need to be reconfigured, which will speed up the loop a little (maximum, that I would expect several milliseconds).

When you call niDCPower Reset, the opening time is reconfigured. On the 4132, anytime, the opening time is reconfigured, must wait a minimum of time to allow a measure being erased. It is because of the behavior of one of the hardware components that we use. If you prevent the reconfiguration of your opening time during each run, your speed should be improved significantly.

Please let us know if these suggestions help, or if you have any other questions.

Thank you

Tobias Gordon

Software engineer

DC accuracy

National Instruments

Tags: NI Products

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