Quatech HSU-200 사용자 설명서

Making external connections 

RS-232 serial connections 

The Freedom USB-100 RS-232 adapters all come with standard male 
DB-9 connectors. The figure below shows the pin designations. 

Figure 37 - RS-232 DB-9 pin designations 

 

RS-232-C devices are classified by their function as either Data 

Terminal Equipment (DTE) or Data Communication Equipment 

(DCE). 

Figure 38 - Use of DTEs and DCEs in a communication link 

 

Freedom USB-100 adapters are DTE devices that conect to peripheral 

equipment through a male DB-9 connector. The following table lists 

the serial port connector definitions. 

Table 3 - RS-232 DB-9 signal definitions 

DTE 
connection 

RS-232 signal  
description 

DB-9 

Data Carrier Detect (DCD)  1 
Receive Data (RxD) 

2 

Transmit Data (TxD) 

3 

Data Terminal Ready (DTR)  4 
Signal Ground 

5 

Data Set Ready (DSR) 

6 

Request To Send (RTS) 

7 

Clear To Send (CTS) 

8 

Ring Indicate (RI) 

9 

DTE- and DCE-type devices have complementary pinouts that allow 

terminals and modems to connect directly using a one-to-one cable as 
shown in Figure 39.