NI 623X Physical Channels

In physical channel names, Dev1 is the default device name for NI 623X devices. You can change these names in MAX.

Analog Input

Refer to the following table for the physical channel naming conventions for each 623X device.

Analog Output

NI 623X devices have m analog outputs corresponding to m analog output physical channels ranging from Dev1/ao0 to Dev1/ao(m-1). Refer to the hardware documentation for the number of analog outputs for your device.

Digital Input and Output

NI 623X devices have two ports, port 0 and port 1. Port 0 has six digital input lines, Dev1/port0/line0 through Dev1/port0/line5. Port 1 has four digital output lines, Dev1/port1/line0 through Dev1/port1/line3. You can use port 0 as static digital input lines or input PFI lines, PFI 0..5. You can use port 1 as static digital output lines or output PFI lines, PFI 6..9. When any of PFI lines 0..9 is used as a digital I/O signal, it uses the physical channel name shown in the following table.

Physical channel Dev1/port0 refers to all six input lines, Dev1/port0/line0:5, at once. Physical channel Dev1/port1 refers to all four output lines, Dev1/port1/line0:3, at once.

Tristating Digital Output Channels (NI 6230/6236)

NI 6230/6236 devices support tristating for port 1, the four digital output lines. The power-on state default is to tristate port 1. Tristating is supported only for the entire port at a time, not on a per-line basis. For instance, port 1 remains tristated as long as no lines on port 1 are toggled to generate a value. After a line on port 1 is toggled, all lines on the port are driven to logic high or logic low depending on what you choose. The default is logic low.

Counter Input and Output

NI 623X devices have two counter/timers referred to by the physical channel names Dev1/ctr0 and Dev1/ctr1. Unlike the other I/O types, these physical channel names do not refer to terminals on the I/O connector but instead to circuits within the device. There are four primary terminals associated with each counter. These are the terminals used as the SOURCE, GATE, AUX, and OUT functions. NI-DAQmx has default values for these terminals. For counter input tasks, if you know whether your signal provides the SOURCE, AUX, or GATE function and wire your signal to the default, you do not have to set the Input Terminal attribute/property.

In addition, the NI 623X has one frequency generator. The output terminal of the frequency generator is FREQOUT. The default for FREQOUT is PFI 8. When using FREQOUT, you can continue to use both ctr0 and ctr1 to perform other operations.

The NI 623X uses the same default terminals for common counter applications as other 37-Pin DSUB devices. Refer to 37-Pin DSUB Signal Connections for Counters for default terminals for NI 623X devices.