Abstract: A communications adapter for interfacing a transceiver and a line including a synchronous receiver-transmitter programmed by a controller to operate the receiver-transmitter in different data formats during a single frame transmission to or reception from a transmitter/receiver and including logic programmed by a controller for controlling the operation of a transmitter/receiver on a bit level to halt the transmitter/receiver during programming changes of format between and during a frame. For frame transmission to a transmitter/receiver, the receiver-transmitter is programmed for a first portion of a frame for a number of bits per character as a function of transmitter/receiver and line protocol and for second portion of a frame for a number of bits per character as a function of line protocol.

Abstract: A single circuit board, having a communication interface adapter circuit including I/O and power supply connectors, switches and indicators mounted directly thereto, is mounted to the rear panel of a first housing portion via stand-off and fasteners. The front and rear panels of a first housing portion are parallel to the printed circuit board and include apertures to allow external access to the connectors, switches and indicators. A power supply in a separate housing is mounted to the rear panel of and external to the first housing portion.