User:Electron9/Serial port
Pinouts
[edit]The following table lists commonly-used RS-232 signals and pin assignments.[1]
| Signal | Origin | DB-25 pin | DE-9 pin | TIA-561 pin | Yost pin | DEC MMJ | |||
|---|---|---|---|---|---|---|---|---|---|
| Name | Typical purpose | Abbreviation | DTE | DCE | |||||
| Data Terminal Ready | OOB control signal: Tells DCE that DTE is ready to be connected. | DTR | ● | 20 | 4 | 3 | 2 | 1 | |
| Data Carrier Detect | OOB control signal: Tells DTE that DCE is connected to telephone line. | DCD | ● | 8 | 1 | 2 | 7 | 6 | |
| Data Set Ready | OOB control signal: Tells DTE that DCE is ready to receive commands or data. | DSR | ● | 6 | 6 | 1 | |||
| Ring Indicator | OOB control signal: Tells DTE that DCE has detected a ring signal on the telephone line. | RI | ● | 22 | 9 | - | - | ||
| Request To Send | OOB control signal: Tells DCE to prepare to accept data from DTE. | RTS | ● | 4 | 7 | 8 | 1 | - | |
| Clear To Send | OOB control signal: Acknowledges RTS and allows DTE to transmit. | CTS | ● | 5 | 8 | 7 | 8 | - | |
| Transmitted Data | Data signal: Carries data from DTE to DCE. | TxD | ● | 2 | 3 | 6 | 3 | 2 | |
| Received Data | Data signal: Carries data from DCE to DTE. | RxD | ● | 3 | 2 | 5 | 6 | 5 | |
| Common Ground | GND | common | 7 | 5 | 4 | 4, 5 | 3, 4 | ||
| Protective Ground | PG | common | 1 | - | - | - | - | ||
| Transmitted Data | Current loop, Transmit+ | TCLD+ | ● | 9[2][3] | |||||
| Transmitted Data | Current loop, Transmit- | TCLD- | ● | 11[2] | |||||
| Received Data | Current loop, Receive+ | RCLD+ | ● | 18[2] | |||||
| Received Data | Current loop, Receive- | RCLD- | ● | 25[2] | |||||
On the IBM XT DB-25 connector all other pins 1,10,12-17,19,21,23-24 are not connected (NC).[2]
References
[edit]- ^ Joakim Ögren. "Serial (PC 9)".
- ^ a b c d e IBM Personal Computer XT Harwdware Reference Library, Asynchronous adapter 1-243
- ^ http://stason.org/TULARC/pc/pc_pinout.html