Step 1 - Update to Microwin 4.0 to SP7 (http://support.automation.siemens.com/WW/view/en/33005232).
Step 2 - Connect the PPI cable to EM277
Step 3 - Access via Profibus, the PG/PC interface has to be configured to "S7ONLINE --> PROFIBUS". For example CP5611 (Profibus). Then in properties "mark" "Only Master on the Bus", select address and baud rate should be bigger then 187kbaud.
Step 4 - You are online & connected to the S7-200 system with only 1 port.
