The following table is a list of internal physical channels for all E Series devices. Different E Series devices have different subsets of channels. These channels are typically for self-calibration, and you can sample them as you would a physical channel present on the I/O connector.

Internal Channel Name Description
_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.
_ao0_vs_aognd A differential terminal with the positive terminal connected to physical channel 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 onboard 5 V reference and the negative terminal connected to the onboard 5 V reference.
_calref_vs_aignd A differential terminal with the positive terminal connected to the onboard 5 V reference 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 onboard 5 V reference.
_ao1_vs_calref A differential terminal with the positive terminal connected to physical channel ao1 and the negative terminal connected to the onboard 5 V reference.
_ao1_vs_ao0 A differential terminal with the positive terminal connected to physical channel ao1 and the negative terminal connected to physical channel ao0.
_boardTempSensor_vs_aignd A differential terminal with the positive terminal connected to the onboard temperature sensor and the negative terminal connected to the ground reference for analog input.
_aignd_vs_aignd A differential terminal with the positive terminal connected to the ground reference for analog input and the negative terminal connected the ground reference for analog input.
_caldac_vs_aignd A differential terminal with the positive terminal connected to the onboard calibration DAC and the negative terminal connected to the ground reference for analog input.
_caldac_vs_calref A differential terminal with the positive terminal connected to the onboard calibration DAC and the negative terminal connected to the onboard 5 V reference.
_PXI_SCXIbackplane_vs_aignd A terminal where a signal being conditioned by a SCXI module is measured across the PXI/SCXI backplane and not the I/O connector. Reading from this channel is valid only on PXI devices inserted in the rightmost PXI slot of a PXI/SCXI combination chassis.