Levels Of Implementation - Motorola MVME167 Series Installation Manual

Table E-1. EIA-232-D Interconnections (Continued)
Pin Signal
Number Mnemonic
22 RI
23
24 TxC
25 BSY

Levels of Implementation

There are several levels of conformance that may be appropriate for
typical EIA-232-D interconnections. The bare minimum
requirement is the two data lines and a ground. The full
implementation of EIA-232-D requires 12 lines; it accommodates:
A middle-of-the-road approach is illustrated in
Signal Name and Description
RING INDICATOR. Output from the modem to the terminal;
indicates to the terminal that an incoming call is present. The
terminal causes the modem to answer the phone by carrying
DTR true while RI is active.
Not used.
TRANSMIT CLOCK (DTE). Input to modem from terminal;
same function as TxC on pin 15.
BUSY. Input to modem from terminal. A positive EIA signal
applied to this pin causes the modem to go off-hook and make
the associated phone busy.
Automatic dialing
Automatic answering
Synchronous transmission
Levels of Implementation
Figure E-1.
E
E-3