OPC server

Hello all,


What is OPC server?
How & where i can use it?
And what is
inprocess
remote
local
concerning with it ?
If Computer is having 2 SCADA system is it possible to share same tags ?

Thanks
sandymax

This site will get you started

http://www.matrikon.com/drivers/opc/

OPC Servers

An OPC server is a piece of software that reads values out of a controller or computer, and makes them available to other applications, such as Plantmetrics, Citect, or Wonderware.

The server software resides in a computer that connects to controllers by a physical means, such as ethernet or RS-485. The software communicates to the controllers via a protocol, such as modbus. Software such as MS Excel can then ask the for information from the server software, such as "Controller 1, Register 12", by asking correctly ("asking correctly" varies depending on the server software and the application seeking data").

The Matrikon software is an excellent piece of software I've used extensively with Unitronics plcs. I use Modbus TCP over an ethernet network. One of the best features is the ability to create "aliases". An alias lets you take a known address for data, "FX1.3:1251", and apply a common-sense name, "FX1.MotorSpeed". You can also scale values through aliasing, which in my case allowed me to use the same Unitronics program on four machines, each with different scalars.

Matrikon has my recommendation. It's good, inexpensive, and the staff are helpful.

TM

Also check www.opcfoundation.org

Thanks for reply
i will like to know what is Inprocess, local OPC servers

Thanks
sandymax