Server User Manual
  Making Hardware Connections 
Manual Documentation Number: ESP901-902_4105m  Chapter 2  15 
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com 
B&B Electronics Ltd – Westlink Commercial Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 – www.bb-europe.com 
Serial Server Serial Port Connector Pin-outs 
Pin-outs for RS-232, RS-422 and RS-485 operation are shown below. 
DB-9M 
Pin 
RS-232 
Signal Name 
DTE RS-422  RS-485 
1  Carrier Detect  DCD  In  RXDA (−) -- 
2  Receive Data  RXD  In  RXDB (+)  -- 
3 Transmit Data TXD Out TXDB (+)  Data B (+) 
4  Data Terminal Ready  DTR  Out  TXDA (−)  Data A (−) 
5 Signal Ground GND --- GND GND 
6  Data Set Ready  DSR  In  CTSA (−) -- 
7  Request To Send  RTS  Out  CTSB (+)  -- 
8  Clear To Send  CTS  In  RTSB (+)  -- 
9  Ring Indicator  RI  In  RTSA (−) 
Figure 11.  Serial Connection Pin-outs for RS-232/RS-422/RS-485 
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For more information on RS-232, RS-422 and RS-485 pin-outs, cable 
connections and loopback connections refer to Appendices A, B and C 
Making Hardware Connections 
16   Chapter 2  Manual Documentation Number: ESP901-902_4105m 
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com 
B&B Electronics Ltd – Westlink Commercial Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 – www.bb-europe.com 










