The ASCII Communication Module (ACM), model 621-0012R, provides an interface between the Logic Manager System and devices that communicate via an asynchronous
serial data link. The ACM communicates with peripheral devices using character strings comprised of ASCII and non-ASCII characters. The single board module is installed in the Logic Manager I/O System and is controlled by the Logic Manager processor via the
discrete and data I/O buses. Transmission and reception of serial information is provided through a 25-pin D series female connector. This serial port may be selected to operate on RS232, RS422, or 20 mA current loop hardware interface by printed circuit board mounted DIP switches.

The ASCII Communication Module is an I/O module that operates according to the user’s ladder logic as interpreted by the module’s configuration. The module can be configured for ABC protocol or a user-defined protocol. The ABC protocol is used by Honeywell IACD’s Industrial Microcomputers. A user defined protocol allows the user to define all the communication formats.