Siemens S7-300 - 6 STEP7 Software Setting

About the detailed instructions of the VCOMM virtual serial port software, please read " VCOMM
virtual Serial Port software Manual.
Here the serial port parameters setting of ETH Adapter CN is introduced.
The baud rate of ETH Adapter CN serial port supports 9600～115200bps,but Siemens STEP7
software only supports 19200bps and 38400bps two baud rate.The other serial port parameters of
STEP7 is fixed as data bit=8 bits, Parity= Odd parity,stop bit=1 bit, abbreviation as 8O1,so you
must set the serial port parameters of ETH Adapter CN is the same as this,or else it can’t build
communication.
Firstly set ETH Adapter CN serial port parameters in parameters setting software , where the serial
port protocol box "RS232" option is supporting RS232/RS485/RS422 communication and must
ensure that this serial port parameters and the STEP7 software parameters are the same,that’s
19200bps
、
8O1 or 38400bps
、
8O1, Otherwise, It can’t normally communicate.
We all use baud rate 19200bps in the following examples.
6. STEP7 software setting
We have setted the serial port parameters of ETH Adapter CN as 19200bps, 8O1 .
When the VCOMM virtual serial port software running on the PC simulate ETH Adapter CN as the
COM port on the PC, the next using is just like traditional PC Adapter, you could choose to connect
the MPI port or DP port of PLC depending on your requirement,and choose the corresponding
protocol option in the “set PG/PC interface”of STEP7 .
Also the MPI or DP baud rate which you choosed in the “set PG/PC interface” of STEP7 must be
same as PLC baud rate, Otherwise, It can’t normally communicate. If you don’t know the PLC MPI
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