Hi Marcus, thanks for your answer.
I was probably not clear about what I want. The solutions you suggest seem to be far to complex. As Nirmal pointed out, I actually only need high quality optocouplers, no more. On Thu, 25 Mar 2004 09:30:26 -0600 (CST), Marcus G <[EMAIL PROTECTED]> wrote: >Hello Johannes, >It sounds like you're setting up a system that requires four analog >inputs (two voltage and two current), and you would like to use an >analog trigger to switch between which signals are measured. No. I just want to use the digital outputs of the DAQ card to switch optocouplers. The optocouplers will switch between several analog measuring signals. They should route these signals to one analog input of a Keithley 2000. >There are >several options of how you can set up such a system. >In terms of measuring the four analog inputs, you should be able to do >this with a DAQ card alone. Many of our cards, including the >AT-MIO-16E-10 (also called a 6020E), have 16 analog input channels >that have an input range of +/-10V. I don't want to measure the four analog inputs with the DAQ card since it isn't precise enough. The input range is too high for some of the analog inputs and the resolution is too low. Also, I can't modify the input range of the DAQ card at runtime. Therfore, we are using external instruments (Keithley 2000 a.a.) for the measurements. My idea was to only use one instrument for the four analog input signals. Then I must provide the switching between the four analog inputs. The idea was to control (switch) some optocouplers with the digital outputs of the DAQ card. The optocouplers should route one of the four analog signals to one Keithley 2000. I set the digital outputs of the DAQ card in the LabView program. Also, the LabView program configures the Keithley 2000 and reads the measuring values from the GPIB. That's all. Regards Johannes
