DVR Security Forum

The 9-pin SUB-D connector is assigned as follows:

1 – switching output (max. 24 V / 50 mA)
2 – RXD (also an optional fourth signal input)
3 – TXD (also an optional extended switching output)
4 – DTR (also an optional extended switching output)
5 – GND
6 – DSR (also an optional third signal input)
7 – RTS (also an optional extended switching output)
8 – CTS (also an optional second signal input)
9 – Switching input