TIA ANSI/TIA/EIA-466-A PDF

Procedures for document transmission

This Standard is concerned with the procedures which are necessary for
document transmission between two facsimile stations operating on voice
band analog circuits.  These procedures essentially comprise the
following:

     - call establishment and call release
     - compatibility checking, status and control command
     - checking and supervision of line conditions
     - control functions and facsimile operator recall

Only the procedures with their corresponding signals are specified in
this Standard.

Classification of operating methods

For the purpose of originally establishing the facsimile connection,
four operating methods are defined herein.  Thus, depending on whether
the called or calling party is operating in a manual or automatic mode
of operation and whether it intends to transmit or receive, a particular
operating method will be chosen.  The particular operation method will
determine the procedures to begin the interchange of signals between the
two terminals.  This interchange of signals is commonly referred to as
handshaking.

The various operating methods are shown in Table 1.