RS-232 Interface



RS-232 (EIA Std.) applicable to the 25 pin interconnection of Data Terminal Equipment (DTE)
and Data Communications Equipment (DCE) using serial binary data.
Pin Signal EIA
CKT
From
DCE
To
DCE
1 Frame Ground AA    
2 Transmitted Data BA   D (Data)
3 Received Data BB D  
4 Request to Send CA   C (Control)
5 Clear to Send CB C  
6 Data Set Ready CC C  
7 Signal Gnd/Common Return AB    
8 Rcvd. Line Signal Detector CF C  
11 Undefined      
12 Secondary Rcvd. Line Sig. Detector SCF C  
13 Secondary Clear to Send SCB C  
14 Secondary Transmitted Data SBA   D
15 Transmitter Sig. Element Timing DB T (Timing)  
16 Secondary Received Data SBB D  
17 Receiver Sig. Element Timing DD T  
18 Undefined      
19 Secondary Request to Send SCA   C
20 Data Terminal Ready CD   C
21 Sig. Quality Detector CG   C
22 Ring Indicator CE C  
23 Data Sig. Rate Selector (DCE) CI   C
24 Transmitter Sig. Element Timing DA   T
25 Undefined