NI 6535/6536/6537 Physical Channels

The 32 individually configurable lines of digital input and output on the NI 6535/6536/6537 are grouped into four 8-bit ports, as shown in the following table. You can choose to configure an entire port for a particular task or only a particular physical channel.

The following table shows the channel names you can use to configure your task in NI-DAQmx. Dev1 in physical channel names is the default device name for NI 6535/6536/6537 devices. You can change the device name in MAX.

Port NI-DAQmx Physical Channel Name (Lines) NI-DAQmx Physical Channel Name (Ports)[1]1 This physical channel name refers to all eight lines in a port at once.
Port 0 Dev1/port0/line0 — Dev1/port0/line7 Dev1/port0
Port 1 Dev1/port1/line0 — Dev1/port1/line7 Dev1/port1
Port 2 Dev1/port2/line0 — Dev1/port2/line7 Dev1/port2
Port 3 Dev1/port3/line0 — Dev1/port3/line7 Dev1/port3
Port 4[2]2 Port 4 is composed of the six PFI lines. Dev1/port4/line0 — Dev1/port4/line5 Dev1/port4

For Ports 0 through 3, you can configure a port width of 8, 16, or 32 bits. To configure a 32-bit port, use the physical channel name Dev1/port0_32. To configure a 16-bit port, use channel names that refer to all the lines in multiple consecutive ports: Dev1/portP_N, where P is 0 or 2 (whichever port number is lower) and N is the total number of lines. For example, to combine Port 2 and 3 into a 16-bit port, specify Dev1/port2_16 as the physical channel.

Using NI-DAQmx, you can configure each physical channel individually by inverting or tristating the physical channel.

PFI Lines

The NI 6535/6536/6537 has six PFI lines. These bidirectional digital lines allow you to route synchronization and timing signals to and from the I/O connector. The following table lists the PFI lines and their timing function.

PFI 0 General-purpose PFI line
PFI 1 General-purpose PFI line
PFI 2 General-purpose PFI line
PFI 3 General-purpose PFI line
PFI 4 General-purpose PFI or the generation Sample clock terminal
PFI 5 General-purpose PFI or the acquisition Sample clock terminal

You can use control lines as extra data lines while using the On Demand sample timing type.

1 This physical channel name refers to all eight lines in a port at once.

2 Port 4 is composed of the six PFI lines.