modbus

author:Mark Rivers, University of Chicago

This is an EPICS module for communicating with Modbus devices using asyn device support.

Table of Contents

• Acknowledgments
• Overview of Modbus
  • Modbus communication links
  • Modbus data types
  • Modbus communications
  • Modbus function codes
  • Modbus addresses
    • Discrete inputs and coils
    • Input registers and holding registers (V memory)
  • Modbus data length limitations
  • More information on Modbus
• Driver architecture
  • Modbus read functions
  • Modbus write functions
  • Modbus write/read functions
  • Platform independence
• Creating a modbus port driver
  • TCP/IP
  • Serial RTU
  • Serial ASCII
  • modbusInterposeConfig
  • drvModbusAsynConfigure
  • Modbus register data types
  • Note for Wago devices
  • Number of drvAsynIPPort drivers for TCP
  • Number formats
• EPICS device support
  • asynUInt32Digital
  • asynInt32
  • asynInt64
  • asynFloat64
  • asynInt32Array
  • asynOctet
  • Template files
• Example Applications
• medm screens
  • modbusDataTypes.adl
  • Koyo1.adl
  • Koyo_8inputs.adl
  • Koyo_8outputs.adl
  • modbusArray.adl
  • modbusStatistics.adl
  • Koyo2.adl
  • Koyo_4ADC.adl
• Debug tracing
  • asynRecord.adl
  • asynRegister.adl