This is a two part example.

- The server program is an application that connects to a PLC,
displays various information, serves it to other (client)
applications on other computers, and receives commands from those clients

- The Client program is an application that connects to the Server program,
displays various information, and can send commands back to the Server.

The advantages of Client/Server are that only one computer will be connecting
to the PLC so there will be less traffic to the PLC and only one computer
will need all the software, setup, and licenses.

The disadvantage of Client/Server is that the Server program must be
running for the Client programs to work. If you refer to the
'OPC and Delphi EZMarquee' example program on PLCs.net, there is info on setting up
a program to be a tray application so it is difficult to close accidentally.


The sample was written with for:
- Delphi
- a PLC-5 named Signal
- RSLinx Pro (RSLinx version must be better than Lite)
- dOPC Software from Kassl www.dopc.kassl.de
- TOOCS Client/Server network components included in zip file
The dOPC and TOOCS components are dynamically created so you don't have to have
them installed into Delphi to open these files.

There are lots of different ways to do Client/Server but I only know this one.
It is fast, easy, and reliable.

There is a test rung in the PLC like so:

XIC B3/100 --- XIC B3/101 --- XIC B3/102 --- OTE B3/103
                           |              |
                           -- XIC B3/103 --
Where:
B3/100 = Enable
B3/101 = Stop
B3/102 = Start
B3/103 = Run

Have fun,

Steve.
sbwiebe@telus.net

