You can read a voltage connected to the Aux BNC using the Aux Channel ADC and its associated circuitry. This function sets the input impedance of the BNC to a low value (50 kΩ) or to a much higher, uncontrolled value.

When the input impedance is set to Low Impedance (50 kΩ), the input voltage is near zero volts even with no signal connected to the BNC. This is the default setting, used to prevent noise when the BNC Input has no connections. NOTE: We do not recommend this setting for measuring external voltages. Depending on the hardware revision, you may see gain errors of up to 5% when you select Low Input Impedance.

When the input impedance is to high impedance (uncontrolled), the BNC input voltage in the absence of an external connection can wander far away from zero and will be noisy and drifty. A quiet (non-noisy) voltage input connected to the BNC will give quiet readings. NOTE: Use this setting whenever you measure an external signal.

Usage: Value = Pstat.SetAuxBNCImpedance(Setting)

Named constants are defined to make code that uses this function more readable. They are:

and

When used as arguments for this function they set the input impedance high and low respectively.