Technical Description
DB-25 Connector Pin Assignments
| Signal |
| Name | Pin # | Mode |
| GND |
| Ground | 7 |
|
| TD |
| Transmit Data | 2 | Output |
| RTS |
| Request To Send | 4 | Output |
| DTR |
| Data Terminal Ready | 20 | Output |
| RD |
| Receive Data | 3 | Input |
| CTS |
| Clear To Send | 5 | Input |
| DSR |
| Data Set Ready | 6 | Input |
| DCD |
| Data Carrier Detect | 8 | Input |
| RI |
| Ring Indicator | 22 | Input |
|
| Figure 7 - |
| ||
|
|
|
Port # | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
TD | 36 | 12 | 27 | 3 | 75 | 51 | 66 | 42 |
RD | 37 | 11 | 28 | 2 | 76 | 50 | 67 | 41 |
RTS | 17 | 31 | 8 | 22 | 56 | 70 | 47 | 61 |
CTS | 16 | 32 | 7 | 23 | 55 | 71 | 46 | 62 |
DTR | 35 | 13 | 26 | 4 | 74 | 52 | 65 | 43 |
DSR | 18 | 30 | 9 | 21 | 57 | 69 | 48 | 60 |
DCD | 38 | 10 | 29 | 1 | 77 | 49 | 68 | 40 |
RI | 15 | 33 | 6 | 24 | 54 | 72 | 45 | 63 |
GND | 34 | 14 | 25 | 5 | 73 | 53 | 64 | 44 |
Figure 8 - DB-78 Connector Pin Assignments
Omega Engineering | Page 10 |