db9 接口定义
serial (pc 9)
(at the computer)
9 pin d-sub male at the computer.
pin name dir description
1 cd carrier detect
2 rxd receive data
3 txd transmit data
4 dtr data terminal ready
5 gnd system ground
6 dsr data set ready
7 rts request to send
8 cts clear to send
9 ri ring indicator
note: direction is dte (computer) relative dce (modem).
information from the hardware book
电路上的标识：
1 gnd
2 txd
5 rts
3 rxd
4 cts
cat插座：
1 gnd
2 serialout 连续输出
3 serial in 连续输入
4 ptt
ft－80c 的 cat 连线软件可来电邮索取
bg5dje@163.com
