FieldTalk Modbus Master Library, Delphi Edition  Library version 2.12.0
IP based Protocols

Classes

class  TMbusIpClientBase
 Base class for all IP based Master Protocol classes. More...
 
class  TMbusTcpMasterProtocol
 MODBUS/TCP Master Protocol class. More...
 
class  TMbusRtuOverTcpMasterProtocol
 Encapsulated Modbus RTU Master Protocol class. More...
 
class  TMbusElamOverTcpMasterProtocol
 Encapsulated Modbus RTU Master Protocol class. More...
 
class  TMbusAsciiOverTcpMasterProtocol
 MODBUS ASCII over TCP Master Protocol class. More...
 
class  TMbusUdpMasterProtocol
 MODBUS/UDP Master Protocol class. More...
 

Detailed Description

The library provides several flavours of IP based Modbus protocols.

The MODBUS/TCP master protocol is implemented in the class MbusTcpMasterProtocol and is the only IP based protocol officially specified by the Modbus organisation.

In addition to MODBUS/TCP, the library offers implementations of both serial protocols RTU and ASCII transported over TCP streams. These are implemented in the classes MbusRtuOverTcpMasterProtocol and MbusAsciiOverTcpMasterProtocol.

Also an implementation for MODBUS/TCP packets transported via UDP is available in form of the class MbusUdpMasterProtocol.

All classes provide functions to establish and to close a TCP/IP connection to the slave as well as data and control functions which can be used after a connection to a slave device has been established successfully. For a more detailed description of the data and control functions see section Data and Control Functions for all Modbus Protocol Flavours.

Using multiple instances of a MbusTcpMasterProtocol class enables concurrent protocol transfers using multiple TCP/IP sessions. They should be executed in separate threads.

See section The MODBUS/TCP Protocol for some background information about MODBUS/TCP.

See section Using MODBUS/TCP Protocol for an example how to use the MbusTcpMasterProtocol class.