ABB Instrumentation Modbus Serial Communications Applications Guide

This document outlines applications for Modbus Serial Communications, including data recording, process changes, and system upgrades, using ABB Instrumentation products like COMMANDER, DATUM, and MOD 30ML. It also provides a detailed FAQ section covering serial interfaces (RS232, RS422, RS485), Modbus protocols (RTU, ASCII, Plus), master/slave configurations, network distances, and hardware considerations.