| Hirosi PIN | Signal Name | DB-25 PIN | RS232 Circuit | V.35 Circuit | EIA530 Circuit |
|---|---|---|---|---|---|
| Shield | 1 | - | - | - | |
| 1 | Transmit Data (+) | 14 | 103 | BA(B) | |
| 2 | Transmit Data (-) | 2 | BA | 103 | BA(A) |
| 3 | Transmit Clock (DCE Source) (-) | 15 | DB | 114 | DB(A) |
| 4 | Receive Data (-) | 3 | BB | 104 | BB(A) |
| 5 | Receive Data (+) | 16 | 104 | BB(B) | |
| 6 | Request to Send (-) | 4 | CA | 105 | CA(A) |
| 7 | Receive Clock (-) | 17 | DD | 115 | DD(A) |
| 8 | Clear to Send (-) | 5 | CB | 106 | CB(A) |
| 9 | Not Used | ||||
| 10 | Data Set Ready (-) | 6 | CC | 107 | CC(A) |
| 11 | Request to Send (+) | 19 | CA(B) | ||
| 12 | Signal Ground | 7 | AB | 102 | AB |
| 13 | Data Terminal Ready (-) | 20 | CD | 108 | CD(A) |
| 14 | Receive Line Signal Detected (DCD)(-) | 8 | CF | 109 | CF(A) |
| 15 | Ring Indicator/Remote Loopack | 25 | 125 | ||
| 16 | Receive Clock (+) | 9 | 115 | DD(B) | |
| 17 | Data Set Ready (+) | 22 | CC(B) | ||
| 18 | Receive Line Signal Detected (DCD) (+) | 10 | CF(B) | ||
| 19 | Data Terminal Ready (+) | 23 | CD(B) | ||
| 20 | Transmit Clock (DTE Source) (+) | 11 | 113 | DA(B) | |
| 21 | Transmit Clock (DTE Source) (-) | 24 | DA | 113 | DA(A) |
| 22 | Transmit Clock (DCE Source) (+) | 12 | 114 | DB(B) | |
| 23 | Local Loopback/Test Mode | -- | 141 | ||
| 24 | Clear to Send (+) | 13 | CB(B) |