D-SUB Connector

The 15-pin female high-density D-SUB connector connects to general purpose digital I/O, which includes six TTL I/O lines, two isolated inputs, and two bidirectional RS-422 ports, which can be used as a quadrature encoder input. The following table shows the connector assignments and descriptions.

Figure 5. 15-pin D-SUB Connector

1378

Table 3. NI PCIe-1477 15-pin D-SUB Connector Pin Descriptions
Pin Number Signal Name Description
1 TTL I/O 0 TTL-compatible Digital I/O or external trigger
2 Iso Input 0+ 24 V-compatible isolated current-sinking digital input
3 Diff 0+ Bidirectional RS-422 I/O (positive side), or quadrature encoder phase A+
4 Diff 1- Bidirectional RS-422 I/O (negative side), or quadrature encoder phase B-
5 TTL I/O 4 TTL-compatible Digital I/O or external trigger
6 TTL I/O 1 TTL-compatible Digital I/O or external trigger
7 TTL I/O 2 TTL-compatible Digital I/O or external trigger
8 Iso Input 1+ 24 V-compatible isolated current-sinking digital input
9 Diff 1+ Bidirectional RS-422 I/O (positive side), or quadrature encoder phase B+
10 TTL I/O 3 TTL-compatible Digital I/O or external trigger
11 Digital Ground Digital Ground reference for quadrature encoder inputs and TTL I/O
12 Iso Input 0-

Iso Input 1-

Common Ground reference for isolated digital inputs
13 Diff 0- Bidirectional RS-422 I/O (negative side), or quadrature encoder phase A-
14 Digital Ground Digital Ground reference for quadrature encoder inputs and TTL I/O
15 TTL I/O 5 TTL-compatible Digital I/O or external trigger
Tip Go to FPGA Digital I/O Node to Connector Pin Mapping for more information how each I/O node in the FPGA maps to the signals on the D-SUB connector.