Bus-Powered M Series Physical Channels

NI-DAQmx Device Considerations

Bus-Powered M Series Physical Channels

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

Analog Input

Depending on your M Series device, you can have from 16 to 32 analog input channels. A 16-channel M Series device has physical channels ranging from Dev1/ai0 to Dev1/ai15 and a 32-channel device from Dev1/ai0 to Dev1/ai31. You can configure the first eight channels as the positive channel of a differential pair. If N is this channel, channel N + 8 is the negative input of the pair. For instance, if you configure channel 1 in differential mode, the positive input is channel 1, and channel 9 is the negative input. For devices with more than 16 AI channels, 16-23, 32-39, 48-55, and 64-71 are also positive channels of a differential pair.

Use only the physical channel name of the positive channel (not both) when creating a differential channel.

Analog Output

An M Series device that supports two analog outputs has analog output physical channels named Dev1/ao0 and Dev1/ao1.

An M Series device that supports four analog outputs has analog output physical channels named Dev1/ao0, Dev1/ao1, Dev1/ao2, and Dev1/ao3.

Digital Input and Output

Most bus-powered M Series devices have two ports, port 0 and port 1. For devices with eight PFI lines, Port 0 has four digital input lines, Dev1/port0/line0 through Dev1/port0/line3, and port 1 has four digital output lines, Dev1/port1/line0 through Dev1/port1/line3. For devices with 16 PFI lines such as the NI 6218, Port 0 has eight digital input lines, Dev1/port0/line0 through Dev1/port0/line7, and port 1 has eight digital output lines, Dev1/port1/line0 through Dev1/port1/line7. You can use port 0 as static digital input lines or input PFI lines. You can use port 1 as static digital output lines or output PFI lines. When any of PFI lines 0..15 is used as a digital I/O signal, it uses the physical channel name shown in the following table.

PFI Signal Physical Channel Name
PFI 0 Dev1/port0/line0
PFI 1 Dev1/port0/line1
PFI 2 Dev1/port0/line2
PFI 3 Dev1/port0/line3
PFI 4 Dev1/port1/line0
PFI 5 Dev1/port1/line1
PFI 6 Dev1/port1/line2
PFI 7 Dev1/port1/line3
PFI 8 Dev1/port0/line4
PFI 9 Dev1/port0/line5
PFI 10 Dev1/port0/line6
PFI 11 Dev1/port0/line7
PFI 12 Dev1/port1/line4
PFI 13 Dev1/port1/line5
PFI 14 Dev1/port1/line6
PFI 15 Dev1/port1/line7

Physical channel Dev1/port0 refers to all four or eight lines, Dev1/port1/line0:3 or Dev1/port1/line0:7, at once. Physical channel Dev1/port1 refers to all four or eight lines, Dev1/port1/line0:3 or Dev1/port1/line0:7, at once.

The NI 6212 and NI 6216 have 16 lines of digital input and output named Dev1/port0/line0 through Dev1/port0/line15. These lines belong to a single port, and the physical channel Dev1/port0 refers to all 16 lines at once. Port 0 can perform static digital I/O operations only.

The NI 6212 and NI 6216 have two more ports, port 1 and port 2. Port 1 has eight digital I/O lines, Dev1/port1/line0 through Dev1/port1/line7. Port 2 has eight digital I/O lines, Dev1/port2/line0 through Dev1/port2/line7. Port 1 and port 2 can be used as static digital I/O lines or PFI lines, PFI 0..15. When any of PFI lines 0..15 is used as a digital I/O signal, it uses the physical channel name shown in the following table.

PFI Signal Physical Channel Name
PFI 0 Dev1/port1/line0
PFI 1 Dev1/port1/line1
PFI 2 Dev1/port1/line2
PFI 3 Dev1/port1/line3
PFI 4 Dev1/port1/line4
PFI 5 Dev1/port1/line5
PFI 6 Dev1/port1/line6
PFI 7 Dev1/port1/line7
PFI 8 Dev1/port2/line0
PFI 9 Dev1/port2/line1
PFI 10 Dev1/port2/line2
PFI 11 Dev1/port2/line3
PFI 12 Dev1/port2/line4
PFI 13 Dev1/port2/line5
PFI 14 Dev1/port2/line6
PFI 15 Dev1/port2/line7

Physical channel Dev1/port1 refers to all eight lines, Dev1/port1/line0:7, at once. Physical channel Dev1/port2 refers to all eight lines, Dev1/port2/line0:7, at once.

Counter Input and Output

All M Series 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.

16-PFI Line Devices (NI 6218)

Counter SOURCE Default GATE Default AUX Default OUT Default
Dev1/ctr0 PFI 0 PFI 1 PFI 9 PFI 4
Dev1/ctr1 PFI 3 PFI 2 PFI 10 PFI 5

16-PFI Line Devices (NI 6212/6216)

Counter SOURCE Default GATE Default AUX Default OUT Default
Dev1/ctr0 PFI 8 PFI 9 PFI 10 PFI 12
Dev1/ctr1 PFI 3 PFI 4 PFI 11 PFI 13

8-PFI Line Devices (Such as the NI 6210/6211/6215)

Counter SOURCE Default GATE Default AUX Default OUT Default
Dev1/ctr0 PFI 0 PFI 1 PFI 0 PFI 4
Dev1/ctr1 PFI 3 PFI 2 PFI 3 PFI 5

Refer to Bus-Powered M Series Signal Connections for Counters for more information.