Hello, in our LabView applications we have to measure several voltages and currents. We use a AT MIO 16 E 10 DAQ card, but it is not good enough for 2 voltages 2 currents. Therefore, we use exernal GPIB measuring instruments for them (Keithley 2000 a.a.). However, I think we could come along with only one Keithley 2000 since the timing is no issue (1 scan per sec is enough). I need some switch controlled by LabView that switches the analog measuring signals to two Keithley 2000 (analog) inputs (one for voltage, the other for current measurement, respectively).
I found out that I can't do this with the DAQ card alone. I can't use the analog outputs since I don't want a A/D - D/A conversion included. Note that the measuring voltages can be ~100 mV. But I could be wrong since I am actually a software guy so please correct me if this is possible with the DAQ card only. My idea is as follows: I could use the digital outputs of the DAQ card and connect them to some opto coupler or relais with TTL input. The opto couplers or relais would switch the analog measuring signals according to the digital outputs of the DAQ card and finally according to LabView. I couldn't find such a switcher board in the NI catalog. They have switchers, but they seem to switch voltages >3V only. But maybe someone suggests a board from another company which suits better. I just wouldn't like so much soldering my own board since my knowlege of opto couplers, relais and hardware in general is really limited. Best regards Johannes
