Coupling

Specify input coupling mode

Description

The Coupling property indicates the coupling mode used for the analog input signal connection. You cannot change the value for devices that support only one mode. For devices that support both AC and DC coupling, you can specify the mode by changing this property value.

If Coupling is set to 'DC', the signal input is connected directly to the amplifier, allowing measurement of the complete signal including its DC bias component. This is typically used with slowly changing signals such as temperature, pressure, or voltage readings.

If Coupling is set to 'AC', a series capacitor is inserted between the input connector and the amplifier, filtering out the DC bias component of the measured signal. This is typically used with dynamic signals such as audio.

Values

'DC'	Direct input connection to amplifier. Default for any device that supports DC coupling.
'AC'	Series capacitor inserted between the input connector and the amplifier. Default for any device that supports only AC coupling.

Examples

Create a session and add an analog input channel. Then change the coupling mode to 'AC'.

s = daq.createSession('ni');
ch = addAnalogInputChannel(s,'Dev4','ai1','Voltage')

ch.Coupling = 'AC'