console线针脚定义

console线大多是9针或25针的，常用的定义如下：

9针针脚定义：

1. DCD(Data Carrier Detect) 数据载波检测

2. RD (Receive Data)接收数据

3. TD (Transmit Data)发送数据

4. DTR(Data Terminal Ready)数据终端就绪

5. GND (System Ground)地线

6. DSR(Data Set Ready)数据集就绪

7. RTS(Request to Send)发送请求

8. CTS(Clear to Send)清空发送

9. RI (Ring indicator)振铃指示

25针针脚定义：

1. PGND (Protective Ground)保护地

2. TD (Transmit Data)发送数据

3. RD (Receive Data)接收数据

4. RTS (Request to Send)请求发送

5. CTS (Clear to Send)允许发送

6. DSR (Data Set Ready)数据机就绪

7. SG (Signal Ground)信号地

8. CD (Carrier Detect)载波侦测

9. Unused

10. Unused

11. Unused

12. SCLK (Transmit Clock)发送时钟

13. DTR (Data Terminal Ready)数据终端就绪

14. Unused

15. Unused

16. TRCLK (Receive Clock)接收时钟

17. TRD1 (Receive Data)接收数据1

18. TRD2 (Receive Data)接收数据2

19. Unused

20. DSR (Data Signal Rate)数据速率选择输入

21. DCEN (Data Carrier Enable)数据载波允许

22. Unused

23. Unused

24. Unused

25. Unused