Hi all,
I am using a PCI 6052E card with NI-DAQ software to detect the current which passes through one setup. I installed the NI-DAQ software and the PCI card according to the manual book and successfully applied them to measure (-5~+5V) and generate the voltage (-10~+10V). For my application, a power source with 250V~5kV (maximum current is 25 uA) is used. The cathode is connected to the setup while the anode is connected to a resistor of 1000 Ohm and then back to the setup. I attached the input wires of the card to the resistor, and thus the change of the voltage reveals the current passed through the setup.
I turned on the power supply (250~1000V) when the setup is off, the power supply shut down immediately. The read voltage from the card is about 1.1V. This is very strange because the whole circuit is open and the voltage should be zero. If I detach the input wire from the resistor, the power supply resumes. I checked the connecting wires, the BNC-2110 board, the cable between the BNC-2110 board and PCI card, they all fine and work.
Another possibility is that the computer and the power supply do not connect to the same ground. However, the phenomenon does not change while we grounded them. It seems that something is wrong in the PCI card. I did install the PCI card according to the manual book rigidly. Are there some steps missing in the manual book? Could you please help me to solve this problem?
