DTE-DCE Interface Cont

Functional Specifications

o    Figure   shows   the   ordering   and   functionality   of   each   pin   of   a   male connector o    Female  connector  will  be  a  mirror  image  of the  male  so  that  pin  1  in  the plug matches tube 1 in the receptacle and so on o    Each comm function has a mirror or answering function for traffic in the opposite direction to allow for full duplex operation o    For Example, pin 2 is for transmitting data and pin 3 is for receiving data o    Pin 9 and 10 are for future use o    Pin 11 is yet unassigned •     DB9 IMPLEMENTATION o    Most  of  the  pins  in  DB  25  implementation  are  not  necessary  ina single asynchronous connection o    A simpler 9 pin version of EIA 232 is shown in the figure Functioning Steps Step 1: Preparation -Preparation of the interface between DTE and DCE Step 2: Readiness -Checks if all four devices are ready Step 3: Set up -Set up the connection between two DCEs Step 4: Data Transfer -DTE -> DCE -> DCE -> DTE Step 5: Clearing -Turning OFF the connection