Connecting Differential Voltage Signals

You can connect grounded or floating differential signal sources to the PCIe-7856. Connect the positive voltage signal to the AI+ and the negative voltage signal to AI-. To connect grounded differential signals to the PCIe-7856, you must also connect the signal reference to AI GND.

To connect floating differential signals to the PCIe-7856, you must connect the negative and positive signals to AI GND through 1 MΩ resistors to keep the voltage within the common-mode voltage range. If the voltage source is outside the common-mode voltage range, the PCIe-7856 does not read data accurately.