9 pin D-SUB FEMALE connector | | Pin | Function | | 1 | Output--Connects to the Carrier Detect (CD) input | | 2 | Output--Connects to the Received Data (RXD) input | | 3 | Input--Connects to the Transmitted Data (TXD) output | | 4 | Input--Connects to the Data Terminal Ready (DTR) output | | 5 | Signal Ground | | 6 | Output--Connects to the Data Set Ready (DSR) input | | 7 | Not used | | 8 | Not used | | 9 | Not used | | 
9 pin D-SUB MALE connector |
