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Old February 17th, 2017, 11:12 AM   #1
United Kingdom

02js4130 is offline
Join Date: Jun 2014
Location: Wales
Posts: 26
Siemens s7-300 ppi connection masters detected


I am new to Siemens and having difficulties connection to the S7-300. I have recently been connecting to the 200 without a problem so assumed that establishing communications with the 300 would be similar.

This PLC is out of an old control panel and is currently sitting on a desk.

Hardware i am using is the siemens rs232/ppi Multi-master Cable running in to my laptop USB with an Omron serial converter. (Which was fine for the S7-200)

so i am using PC/PPI able PPI.1 (COM3) interface

And when i refresh the PLC shows as UNKNOWN address:2 187.5 kbps which tells me there is some form of communication. The error comes in the form of:

Masters have been detected on this network. Searching all baud rates is not advisable because a network could occur. To search all baud rates, remove or disable all masters.

Please could someone tell me how to overcome this issue, also what is it referring to as a master??
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