C-2 Appendix C 232SS21600 Manual
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104
Chart 3. Modem DB25 Connector to Master Port
Straight Through Connection
Async Modem
Serial Port
DB25 Connector Signal
Direction
232SS2
Master Port (DTE)
DB25 Connector
2 <----------- 2
3 -----------> 3
4 <----------- 4
5 -----------> 5
7 GROUND 7
8 -----------> 8
20 <----------- 20
Chart 4. IBM PC DB25 Connector to Ports A - D (DTE)
Master port DCE, Slave port DTE.
Null Modem Connection
IBM PC
Serial Port
DB25 Connector Signal
Direction
232SS2
Ports A - D (DTE)
DB25 Connector
2 -----------> 3
3 <----------- 2
4 -----------> 5
5 <---------- 4
6 & 8 <---------- 20
7 GROUND 7
20 -----------> 6 & 8