How do I create a serial-MPI connection to S7 with the S7 for Windows Programming Software?

Today I tried to go online and retrieve a program in a working S7 PLC using the S7 for Windows Programming Software.

I get the message "incorrect PLC answer" or "PLC responded incorrectly".  This is when asking for block status. Also, I get the same response when I use the S7 configuration software, and try to download the existing configuration.

Can you let me know, step by step, how to establish, and verify, communication to the S7-300 CPU 315-2 DP.

How do I create a serial-MPI connection to S7 with the S7 for Windows Programming Software?

There are several things you can check in the configuration.

In the product manual check the section in chapter 3.2.11.1 for details - page 48. I would suggest setting up the S7 hardware configuration.

Here are some additional steps to take if you have trouble in the future. 

Choose the following interface settings in "S7 for Windows" Preferences:

PLC Type: S7
Protocol: MPI converter cable
Serial port: COM port the cable is connected to;
Exclusive: enable

If SIEMENS MPI converter:
Baud rate: 19200 or 38400
If IBHsoftec/Helmholz MPI converter:
Baud rate: 115200

If this still does not work, please deactivate the FIFO-Buffer:
Start ⇒ Control Panel ⇒ System ⇒ Hardware ⇒ Device Manager ⇒ Ports ⇒ COM Port ⇒ Port Settings ⇒ Advanced