S7 - Java Comms

Hi everyone,

I was working with Mitsubishi's FX-1N series. We developed a Java software that sent and recived data from that PLC using RS485. Right now we are thinking on migrating to the Siemens S7 family. My problem is that I read the S7-200 documentation and find out that the PLC could comunicate to their software (Step 7 Micro/Win), but it doesn't say anything about the protocol it uses. It says Profibus but I really don't know if we are gonna be able to comunicate to our software in Java, or if we can run profibus in Java. Any comment suits me...

There a few options possible.

The S7-200 support on its onboard ports following protocols:
- PPI(Master/Slave)
- MPI(Slave)
- Freeport (simple ASCII/Binary communication for user own protocols)

PPI and MPI are subsets of Profibus.
There is a PPI specification you can buy (expensive).
For Profibus spec. you must be a member of that org.

Solutions:
1. Use the CPU in freeport mode and add your (existing) own simple protocol(or use modbus).
Other S7-200 panels couldn`t be used on the same port, you need a CPU with 2 ports or EM277 extension module.

2. Write an Java OPC client and use the S7-200 OPC-Server (called PC-Access)
You could use Panels at same port. Server runs on Windows only.

3. Implement PPI protocol -> heavy

4. Take a ethernet extension (CP 243-1-IT) module with built in Java-Webserver and FTP-Server.