User Guide

User Guide

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4 How to work on RS-485

4.1 Introduction to Modbus-RTU RS-485

Modbus protocol is a common protocol used in electronic devices. Through this protocol, the devices

communicate with each other. It has become a common industry standard, widely used in data logger,

sensor equipment and so on. Based on this protocol, devices from different vendors can communicate

with each other for system integration.

Modbus protocol is a master-slave architecture protocol. One node is the Master and the other nodes that

use Modbus protocol to participate in the communication are Slaves. Each slave device has a unique

address. The SenseCAP ORCH S4 has RS485 interface and supports Modbus-RTU and Modbus-RTU

ASCLL. Modbus commands can be used to obtain sensor data or modify communication parameters.

Note:

Default communication parameters: baud rate 9600bps, one start bit, eight data bits, no check, one stop

bit.