Hello Sully;

Welcome to the forum.

If you are planning to use the S7-200 platform, you should download and refer to the following document, it contains most of the basic information you require for the S7-200 hardware and programming (through S7-Microwin).

S7-200 System Manual

Chapter 7 discusses networking the S7-200, and various considerations for setting the PC/PC interfce. See the screenshot below for one specific setting for USB or serial connections.

Hope this helps,

Daniel Chartier

< Spoiler Alert >

The S7-200 uses a special cable when connecting to a PC. It is not a straight DB9 connection. The PLC side RS485 while the PC side is RS232 or USB.

This cable is called a PPI cable.. the protocol used is PPI.

Best to focus your searches to these facts when looking at the information provided by Mr Chartier.

Added - Please notify the guys the order number of the equipment you have. There are 4 variants of the S7-200 for which instructions may differ:
* CPU21x
* CPU22x
* CPU22x CN
* S7-200 SMART

New question published by Jonah Lau is split to a separate thread with the subject Communication with S7 224CPU via a MOXA USB to serial convertor with PPI cable .

Best regards
Jen_Moderator