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Modbus RTU, as well the
Modbus RTU is main station.
5
Use
TCP Client
Realcom protocol
Multi-port serial device server as
TCP Client, and use virtual serial
port,
better
use
Realcom
protocol.
6
No use
TCP Client
None
Suitable for a large number of
devices to connect a cloud, and
generally the cloud is the server
with a public IP in Internet.
7
No use
TCP Server
None
Suitable for device and computer
in the same local network,
monitor
locally
without
cross-Internet communication.
5.1 Virtual Serial Port Mode
If the user software uses COM port to communicate, the virtual serial port mode must be
used. As some PLC software, configuration software, instrument software and so on.
Check to see if both the computer and the device are on the local network:
1) If the computer is a server that rents a public network IP on the Internet, then the
device must use the TCP client to connect the server. At this point, you can select
the
②
and the
⑤
in table 6, and if it is multiple serial port servers, you must
choose the
⑤
.
2) Both are in the local network (which can ping each other), depending on whether the
upper machine active query or the device initiatively sends the data. If it is the device
initiatively sending data, it is necessary to use the
②
type that the device as TCP
Client, otherwise you can choose the
①
type.
5.2 Direct TCP/IP Communication Mode
If you don't need the Modbus TCP protocol conversion and virtual serial port, here the
user software can directly do TCP/IP communication with the Ethernet port of serial
device server, the serial device server convert the TCP/IP data to serial port data.
In general, users of this kind of usage develop their own upper computer network