Our Optos Pumps require DSR/DTR controls to work properly and specific wiring on the RJ12. We sell the cables: Eldex P/N: 6143 CABLE, RS232, USB to RJ12
Below is the information on the rear panel’s RS232 modular jack (connector is RJ-12). It is configured for 9600 baud, 8 data bits, 1 stop bit, and no parity. Pinout is:
| RJ 12 Pin | Function | DB 9 pin |
| 1,6 (white, purple) | Ground | 5 |
| 2 (black) | DSR (Input) | 4 |
| 3 (red) | RXD (Input to pump) | 3 |
| 4 (green) | TXD (Output from pump) | 2 |
| 5 (yellow) | DTR (Output) | 6 |
The pump uses hardware handshaking. It does not transmit on the TXD output if the DSR input is at a low logic level, and it does not receive on the RXD input when the DTR output is at a low logic level. A low logic level is –3.0 to –15 volts and a high logic level is 3.0 to 15 volts.