| Opto-22 Channel |
Pin | Signal | |
| 23 | 1 | 2 | GND |
| 22 | 3 | 4 | GND |
| 21 | 5 | 6 | GND |
| 20 | 7 | 8 | GND |
| 19 | 9 | 10 | GND |
| 18 | 11 | 12 | GND |
| 17 | 13 | 14 | GND |
| 16 | 15 | 16 | GND |
| 15 | 17 | 18 | GND |
| 14 | 19 | 20 | GND |
| 13 | 21 | 22 | GND |
| 12 | 23 | 24 | GND |
| 11 | 25 | 26 | GND |
| 10 | 27 | 28 | GND |
| 9 | 29 | 30 | GND |
| 8 | 31 | 32 | GND |
| 7 | 33 | 34 | GND |
| 6 | 35 | 36 | GND |
| 5 | 37 | 38 | GND |
| 4 | 39 | 40 | GND |
| 3 | 41 | 42 | GND |
| 2 | 43 | 44 | GND |
| 1 | 45 | 46 | GND |
| 0 | 47 | 48 | GND |
| 5V | 49 | 50 | GND |