Omega RS-232 User Manual

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Technical Description 
OMG-USB-232-1 
Page 6 
 
Technical Description 
The  OMG-USB-232-1 utilizes a USB UART. This chip features programmable 
baud rate, data format, 128 byte Dual Port TX Buffer, and 384 byte Dual Port RX 
Buffer. The RS-232 transceiver supports data rates up to 460.8K baud. Refer to 
Appendix C for cable length limitations. 
Features 
• 
Hot-Pluggable device that doesn’t require opening the case 
• 
No system resources are required (i.e. I/O ports or IRQ’s) 
• 
LED status indicators for “USB Enabled”, “TD”, and “RD” 
Connector Pin Assignments (DB25 Male) 
 
Name 
Pin # 
Mode 
TD 
Transmit Data 
Output  
RTS 
Request To Send 
Output  
DTR 
Data Term Ready 
20 
Output  
GND 
Ground 
 
RD 
Receive Data 
Input  
DCD 
Data Carrier Detect 
Input  
DSR 
Data Set Ready 
Input  
CTS 
Clear To Send 
Input  
RI 
Ring Indicator 
22 
Input  
 
Note: These assignments meet EIA/TIA/ANSI-574 DTE specifications for DB-25 
type connectors.