DB15P Input Connector Pin Assignments
| 1 | Channel 1 first LED |
| 9 | Channel 1 first LED (electrically tied at opto coupler output to pin 1 circuit) |
| 2 | Channel 2 second LED |
| 10 | Channel 2 second LED (electrically tied at opto coupler output to pin 2 circuit) |
| 3 | Channel 3 third LED |
| 11 | Channel 4 fourth LED |
| 4 | Channel 5 fifth LED |
| 12 | Channel 6 sixth LED |
| 5 | Input signal return (DC- or AC-) |
| 13 | Not used |
| 6 | Not used |
| 14 | Not used |
| 7 | Conflict signal output (Ground true) |
| 15 | +12 VDC power |
| 8 | Ground (+12 VDC return) |