Today is...
Thursday, August 22, 2019
Welcome to Control.com, the global online
community of automation professionals.
Featured Video...
Featured Video
A demonstration of EtherCAT control of linear motors using the CTC EtherCAT master.
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
JAVA agent for MODBUS4J
Developing JAVA code to communicate with Modbus devices/controllers present in it's network using MODBUS4J.
By vijay chelliah on 28 May, 2019 - 2:07 am

I need to develop a JAVA agent code which will communicate with Modbus devices/controllers present in it's network using MODBUS4J.

I have a question regarding how should i designate my code whether as a Master of slave. If master, can a network have multiple masters? And if a slave, can a slave get readings from master controllers (which in turn has all other slave's readings)?

By James Ingraham on 29 May, 2019 - 3:05 pm
1 out of 1 members thought this post was helpful...

Modbus/TCP uses slightly different terminology. A Modbus server is generally a slave, and a client is a master. There are devices that can be both. Typically, your Java app will be a client / master. While there can be many clients / masters on one network, there are issues when one server / slave has more than one client / master. Basically, you can have multiple clients reading data, but if you've got multiple clients writing data then someone's commands are going to be over-ridden. Note that some devices only allow one client, but this is rare.

-James Ingraham
Sage Automation, Inc.