SCXI and SCC Physical Channels

NI-DAQmx Device Considerations

SCXI and SCC Physical Channels

SC1Mod1 is the default device name for an SCXI module, where SC1 is the default chassis ID, and Mod1 refers to the slot number. These names can be changed in MAX.

Analog Input

An SCXI module usually has eight or 32 analog input channels; refer to your device documentation to be sure. These physical channel names are of the form SC1Mod<slot#>/ai0 to SC1Mod<slot#>/aiN, where <slot#> is the chassis slot number of the module, and N equals the number of analog input channels on the module minus one. For example, SCI1Mod1/ai31 is the highest numbered physical channel for a module with 32 analog input channels.

An SCC module has either one or two physical channels named SCC1Mod<J connector#>aiN, where <J connector#> is the number of the J connector where the SCC module resides, and N is the channel number. SCC1 is the SCC connector block ID (for example, SCC1Mod1/ai0).

NI PXI-4224 Only—You cannot scan channel ai7 and the CJC channel simultaneously in a task, since the CJC channel is multiplexed to channel 7. However, when you make a thermocouple measurement on ai0:7 with internal CJC, NI-DAQmx automatically reads the CJC channel at the beginning of the measurement and then scans the rest of the channels correctly.

Analog Output

An SCXI module has some number of output channels for voltage or current. These physical channel names are of the form SC1Mod<slot#>/ao0 to SC1Mod<slot#>/aoN, where <slot#> is the chassis slot number of the module, and N equals the number of analog output channels on the module minus one. For example, SC1Mod1/ao5 is the highest numbered physical channel on a module with six channels.

Digital Input and Output

An SCXI digital module has eight, 16, or 32 lines named SC1Mod<slot#>/port0/line0 through SC1Mod<slot#>/port0/lineN, where <slot#> is the chassis slot number of the module, and N is the number of digital lines minus one. For example, SC1Mod1/port0/line31 is the highest numbered line for a module with 32 lines. These lines belong to a single port and the physical channel named SC1Mod<slot#>/port0 refers to all the lines at once.

An SCC module has either one digital input line or one digital output line with names of the form SCC1Mod<J connector#>diN or SCC1Mod<J connector#>diN, where <J connector#> is the number of the J connector where the SCC module resides, and N is the channel number. SCC1 is the SCC connector block ID (for example, SCC1Mod1/di0).