Modbus Slave Driver

Help Contents

Introduction

Modbus is a communications protocol for Programmable Logic Controllers (PLCs) openly published by Modicon (now part of Schneider Electric). Since its publication in 1979 Modbus has been widely adopted as a communications protocol for PLCs and other types of device.

The Modbus Slave driver receives and processes requests from Modbus drivers in other products. The Modbus slave driver supports these variants of the Modbus protocol:

Protocol Description
Modbus RTU 8-bit serial binary protocol
Modbus ASCII 7 bit serial ASCII protocol
Modbus TCP TCP/IP protocol

Supported Modbus Commands

The Modbus Slave Driver supports these Modbus commands:

CommandDescription
01Read coil status
02Read input status
03Read holding registers
04Read input registers
05Force single coil
06Preset single register
08Diagnostics
11Read comm event counter
15Force multiple coils
16Preset multiple registers
17Report Slave ID

Fernhill SCADA Modbus Slave Tags

The Modbus Slave driver provides these tag types to support communication using the Modbus protocol:

Icon Tag Type Version Description
Channel Icon Modbus Slave TCP Channel Tag 3.10 A TCP/IP Server allowing connections from Modbus drivers in other products.
Channel Icon Modbus Slave Serial Channel Tag 3.10 A serial port used to receive and process Modbus requests.
PLC Device Icon Modbus Slave Device 3.10 A virtual Modbus device.

Further Information

Modbus Protocol

For a description of the Modbus Protocol.

Fernhill SCADA Drivers

For information about other drivers available in Fernhill SCADA.

Glossary

For the meaning of terms used in Fernhill SCADA.