modbus: Modbus Support - Release Notes

Release 3-0

June XXX, 2019

This is a major rewrite of the driver, changing from C to C++ inheriting from asynPortDriver. The major reason for the change is to be able to invoke the class methods such as drvModbusAsyn::doModbusIO() from other drivers. This allows drivers that communicate with Modbus devices to call methods to perform the Modbus I/O directly, which was not possible with the previous C API.

The new driver should be completely backwards compatible with previous versions, so no changes to IOC startup scripts or OPI displays are required.

A new example program, testClient.cpp, has been added. This program demonstrates how to instantiate a drvModbusAsyn object and use it to perform Modbus I/O to an external device. This example is a pure C++ application running without an IOC. The same code could be used in a driver in an IOC.

Release 2-11

June 28, 2018

Release 2-10-1

September 15, 2017

Release 2-10

September 15, 2017

Release 2-9

August 23, 2016

Release 2-8

February 11, 2016

Release 2-7-1

May 6, 2015

Release 2-7

August 19, 2014

Release 2-6

April 10, 2014

Release 2-5

October 2, 2013

Release 2-4

May 22, 2012

Release 2-3

Sept 9, 2011

Release 2-2

March 13, 2011

Release 2-1

November 7, 2010

Release 2-0

November 26, 2009

Release 1-3

September 19, 2008

Release 1-2

September 6, 2007

There is a known limitation with using serial interfaces. It is not currently possible to have multiple Modbus servers connected to a single serial port. This is a limitation of the asynInterposeInterface architecture used. It is fixed in release 2-0.

Release 1-1

April 30, 2007

Initial release of modbus module.