This document describes the MODBUS over Serial Line protocol. MODBUS Serial Line protocol is a Master-Slave protocol. This protocol takes place at level 2 of the OSI model. A master-slave type system has one node (the master node) that issues exp

主从站通讯实验,里面描述了modbus主站与从站的通讯实验，用西门子step7打开。-Master and slave communication experiment, which describes the modbus master and slave communication experiment stations step7 with Siemens Open.

Arduino MODBUS 232 Libraries