RS485 TO ETH ( B)
port — "Serial server serial port — "COM3. Conversely, COM3 to COM2 can also transmit data:
COM3 — "Serial server serial port — "Serial server network port — "Vircom — " COM2. Figure
shows the situation of both parties sending and receiving data.
If COM4 is replaced by a user serial port device, COM5 can communicate with the user
device.
Communication via virtual serial port
4 . 7 . MODBUS TCP TEST
By default, serial and network port data is transparently transmitted. If you need to convert
Modbus TCP to RTU, you need to select "Modbus_TCP Protocol" as the conversion protocol in
the device setting dialog box, as shown in the figure below. At this time, the device port is
automatically changed to 502. At this time, the user's Modbus TCP tool is connected to the 502
port of the serial server's IP, and the sent Modbus TCP commands will be converted into RTU
commands and output from the serial port. For example, if the serial port server receives the
Modbus TCP command of 00 00 00 00 00 06 01 03 00 00 0a, the serial port outputs the
command of 01 03 00 00 00 0a c5 cd. Note: The serial port may send multiple 01 03 00 00 00 0a
c5 cd commands. This is because the default Modbus adopts the storage mode and will
automatically train and query commands in turn. How to switch to non-storage mode will be
explained later.
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