Internal Channels for S Series Devices

NI-DAQmx Device Considerations

Internal Channels for S Series Devices

On an S Series device, you can either acquire a signal present on the I/O connector, or you can acquire a signal that is being generated from the internal calibration multiplexer. The channels available on this multiplexer are typically used for calibration purposes, but you can also sample them as you would a physical signal present on the I/O connector. To read from one of these internal channels, you must use one of the device's AI physical channels (Dev1/ai0 through Dev1/ai7) when creating the virtual channel. The physical channel specifies the ADC for the internal channel. You can then set the appropriate string value on the Input Source channel attribute/property.

note Note   All S Series devices must have the same Input Source setting on all channels. The NI PCI-6110 and NI PCI-6111 devices cannot acquire from more than one ADC at a time when using an internal channel.

NI PCI-6110, NI PCI-6111, NI 6115, NI 6120 Internal Channels

  • _external_channel
  • _aognd_vs_aognd
  • _aognd_vs_aignd
  • _ao0_vs_aognd
  • _ao1_vs_aognd
  • _calref_vs_calref
  • _calref_vs_aignd
  • _ao0_vs_calref
  • _ao1_vs_calref

NI PCI-6143 Internal Channels

  • _external_channel
  • _aignd_vs_aignd
  • _calref_vs_aignd
  • _calSrcHi_vs_aignd
  • _calref_vs_calSrcHi
  • _calSrcHi_vs_calSrcHi
  • _aignd_vs_calSrcHi

NI PXI-6132/6133 Internal Channels

  • _external_channel
  • _aignd_vs_aignd
  • _calref_vs_aignd
  • _calSrcMid_vs_aignd
  • _calSrcHi_vs_aignd
  • _calref_vs_calSrcHi
  • _calSrcMid_vs_calSrcHi
  • _calSrcHi_vs_calSrcHi
  • _aignd_vs_calSrcHi

NI PCI-6154 Internal Channels

  • _external_channel
  • _aignd_vs_aignd
  • _calref_vs_aignd
  • _calSrcHi_vs_aignd
  • _aignd_vs_calSrcHi
  • _calref_vs_calSrcHi
  • _calSrcHi_vs_calSrcHi
  • _aox_vs_aognd

The following table describes all S Series internal channels.

Internal Channel Name Description
_external_channel The differential terminal on the I/O connector that is typically used for acquiring data.
_aignd_vs_aignd A differential terminal with the positive and negative terminals both connected to the ground reference for analog input.
_aognd_vs_aognd A differential terminal with the positive and negative terminals both connected to the ground reference for analog output.
_aognd_vs_aignd A differential terminal with the positive terminal connected to the ground reference for analog output and the negative terminal connected to the ground reference for analog input.
_aox_vs_aognd A differential terminal with the positive terminal connected to the analog output physical channel, such as ao0, and the negative terminal connected to the ground reference for analog output.
_ao1_vs_aognd A differential terminal with the positive terminal connected to physical channel ao1 and the negative terminal connected to the ground reference for analog output.
_calref_vs_calref A differential terminal with the positive terminal connected to the internal calibration reference voltage and the negative terminal connected to the internal calibration reference voltage.
_calref_vs_aignd A differential terminal with the positive terminal connected to the internal calibration reference voltage and the negative terminal connected to the ground reference for analog input.
_ao0_vs_calref A differential terminal with the positive terminal connected to physical channel ao0 and the negative terminal connected to the internal calibration reference voltage.
_ao1_vs_calref A differential terminal with the positive terminal connected to physical channel ao1 and the negative terminal connected to the internal calibration reference voltage.
_calSrcHi_vs_aigndA differential terminal with the positive terminal connected to the calibration PWM and the negative terminal connected to the ground reference for analog input.
_calref_vs_calSrcHiA differential terminal with the positive terminal connected to the internal calibration reference voltage and the negative terminal connected to the calibration PWM.
_calSrcHi_vs_calSrcHiA differential terminal with the positive and negative terminals connected to the calibration PWM.
_aignd_vs_calSrcHiA differential terminal with the positive terminal connected to the ground reference for analog input and the negative terminal connected to the calibration PWM.
_calSrcMid_vs_aigndA differential terminal with the positive terminal connected to the calibration PWM and the negative terminal connected to the ground reference for analog input. _calSrcMid is the divided down version of _calSrcHi.
_calSrcMid_vs_calSrcHiA differential terminal with the positive and negative terminals connected to the calibration PWM. _calSrcMid is the divided down version of _calSrcHi.