This Appendix describes the pinouts of the various connectors on the Audio/Serial Option mezzanine card.
The Audio/Serial Option serial ports are female DB-9 connectors. Figure A-1 shows the pin numbering of the connectors.
Table A-1 describes the pinouts of the DB-9 connectors in both RS-232 and RS-422 modes.
Table A-1. Audio/Serial Option Serial Connector Pinouts
Pin Number | RS-232 Mode | RS-422 Mode |
|---|---|---|
1 | N/C | Transmit high (TX_H) |
2 | Transmit low (TX_L) | Transmit low (TX_L) |
3 | Receive low (RX_L) | Receive low (RX_L) |
4 | Request to send (RTS) | Request to send (RTS) |
5 | Clear to send (CTS) | Clear to send (CTS) |
6 | N/C | Receive high (RX_H) |
7 | Signal ground | Signal ground |
8 | Data carrier detect (DCD) | Data carrier detect (DCD) |
9 | Data terminal ready (DTR) | Data terminal ready (DTR) |
All audio jacks accept 3.5 mm stereo phone plugs. The microphone input can be used with a mono plug for mono input signals. Other inputs can be used with mono plug, which short the ring signal to ground.
Table A-2 lists the tip, ring, and sleeve connections for the various audio connectors.
Table A-2. Audio Connector Tip, Ring, and Sleeve Assignments
Connector | Tip | Ring | Sleeve |
|---|---|---|---|
Microphone | Input (mono) | N/C (mono) | Ground |
Line-level input | Left | Right | Ground |
Line-level output | Left | Right | Ground |
Headphone | Left | Right | Ground |
Digital I/O | Output | Input | Ground (for this circuit only; isolated from analog audio ground) |