APPENDIX: Pinouts
Appendix: Pinouts
Table A-1. Pinning of the RS-232 connector (DB25 female).
Pin Number and Signal | Function |
Pin1 — Frame Ground | Connects the Converter’s frame ground to the |
| frame ground of the |
Pin 2 — TD | When the Converter is set to DCE, data is received |
| on Pin 2 and the TX LED lights up when Pin 2 is a |
| “space” (logical zero). When the Converter is set |
| for DTE, data is output on Pin 2, in which case the |
| RX LED lights up when Pin 2 is a “space.” |
Pin 3 — RD | When the Converter is set for DCE, data is output |
| on Pin 3. The RX LED lights up when Pin 3 is a |
| “space.” When the converter is set for DTE, data is |
| received on Pin 3 and the TX LED lights up when |
| Pin 3 is a “space.” |
Pin 4 — RTS | When the Converter is set for DCE, RTS is an input |
| which turns on the |
| When the Converter is set for DTE, RTS is always |
| an output and is always true. (In DTE mode, CD |
| controls the |
Pin 5 — CTS | When the Converter is set for DCE, CTS is an |
| output that follows the RTS/DTR input. When the |
| converter is set for DTE, CTS is not used. |
Pin 6 — DSR | When the Converter is set for DCE, DSR is true. |
| When the Converter is set for DTE, DSR is not |
| used. |
Pin 7 — Signal Ground | Connects the signal ground of the Converter to the |
| signal ground of the |
Pin 8 — CD | When the Converter is configured DCE, CD is |
| always true (and RTS controls the |
| driver). When the Converter is set for DTE, CD is |
| an input which turns on the |
| when true. |
Pin 20 — DTR | When the Converter is set for DTE, Pin 20 is true. |
15