Totalflow 6700 Series FCU Enron Modbus ASCII Protocol Implementation

This document describes the implementation of Enron Modbus ASCII communications for Totalflow 6700 series FCUs, detailing the protocol's master-slave architecture, message frame formats, and supported function codes. It specifies the use of ASCII mode with LRC error checking, register groupings for boolean, integer, floating point, and archive data, and the subset of Gould Modbus function codes implemented for Enron's host computer system.