Pin Type

Pin Name

Pin No

I/O

TTL

Remarks

Connection Interface

（DB9）

NC

1                      

RS232 standard connection to PC or other RS232 device.

RXD

2

O       

Io>15mA

TXD

3

I

Ri>5KΩ

NC

4

GND

5

I/O

Connect to Earth Line

NC

6

RTS

7

I

Ri>5KΩ

CTS

8

O

Io>15mA

NC

9