Comments on: Selecting a Allen Bradley Controllogix Network

By: 2

Mon, 05 May 2008 10:10:21 +0000

By: kisame

kisame — Sun, 04 May 2008 19:28:59 +0000

The hardware and wires are the same, Ethernet commonly uses Cat 5E wire and RJ-45 8 conductor connectors. They are the ones that look like an overgrown modular phone plug.

Modbus is a communications protocol, and would not be the same protocol as what your home or office network is using to communicate between computers and printers even though it is Ethernet hardware and wiring.

Modbus would commonly be used between a PLC and other devices such as an engine, turbine or generator controller (Many such devices exist) to gather data and take it back to a central HMI (Human-Machine Interface) or alarm annunciator. Some such devices can be controlled using Modbus as well.

By: sadasivam s

sadasivam s — Sun, 04 May 2008 15:46:36 +0000

An interface establishes a connection or boundary between the software and hardware. Say, if you want to access information about RAM an interface would provide the programming required to get the information displayed.

Protocol provides a method to acquire the communication. When talking RS232/Rs485 you are identifying converters which manipulate modulation.

For the quality of connectivity over distances you are indeed on the right track. RS232 coupled with Modbus will give you an overall better quality because the transmittion is sent over as plain form (text). Modbus is peer-to-peer but can perform over point-to-point and multidrop networks.

By: rolando m

rolando m — Sun, 04 May 2008 00:38:45 +0000

Modbus is the protocol developed by Modicon to talk with a
RTU (Remote Terminal Unit)
Your question does not make sense…….

By: samir281071

samir281071 — Sat, 03 May 2008 15:23:31 +0000

a "Modbus Splitter" allows two or more Modbus Masters to communicate with a network of one or more Modbus Slaves: Thus "Splitting" the network and allowing multiple Masters to communicate with a single network of Modbus Slaves.

By: }}}~~~~>

}}}~~~~> — Sat, 03 May 2008 06:58:06 +0000

Modbus allows for communication between many devices connected to the same network, Not just computers, but different devices

Take a look at the wiki for exaples and more detailed info
http://en.wikipedia.org/wiki/Modbus

By: Mad Dog

Mad Dog — Fri, 02 May 2008 22:10:40 +0000

never heard of such a thing

By: sh_sunsea

sh_sunsea — Fri, 02 May 2008 20:59:26 +0000

Modbus is a popular (and cheap/easy) protocol that all Schneider/Modicon PLCs speak. It is cheap because it is in the public domain and everyone has written drivers using that. Twidosoft and Twidosute (free downloads) botj contain Modbus drivers that can be configured, verified, and run with the Modicon PLCs.

By: sh_sunsea

sh_sunsea — Fri, 02 May 2008 19:41:32 +0000

Slavery is outlawed in most countries. You'd better watch what you say.

By: d3sus

d3sus — Fri, 02 May 2008 14:06:04 +0000

Man great work,its relly admirable,I was wondering if i can get this project to have an idea on how to work with citect scada,iam a beginner i hope ill get better like you sumday ,Best of luck for the future,You have a fan of your work.