Waveshare UART TO ETH (B) User guide

RS485 TO ETH ( B)

UART TO ETH (B)

User Manual

Figure 1 UART TO ETH (B)

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RS485 TO ETH ( B)

1 . OVERVIEW

It is a UART to Ethernet module designed for industrial environments, small in size, easy to
embed and integrate, with device data collector/IoT gateway, serial server, Modbus gateway, MQTT
gateway, UART to JSON, and many other functions in one. It has a UART interface and an Ethernet
interface.You can directly integrate it into the device application of your own UART/RS232/RS485
port

When used as a common serial port server, connect the UART TO ETH (B) network port to
the Ethernet, and the host computer software can use TCP/ UDP transparent transmission or
virtual serial port mode to send data to UART TO ETH (B) On the UART interface; the data
received on the UART interface will also be transmitted to the software or virtual serial port on
the TCP side. In the virtual serial port mode, the serial port software connected to the virtual
serial port can be used without any need.

When used as a Modbus gateway, UA RT TO ETH (B) supports Modbus TCP to Modbus RTU,

so that the host computer uses Modbus TCP protocol to collect data from UART /RS 485
Modbus RTU devices. On the contrary, if the UART/RS485 terminal is used as the master
station, it can also be used. The supported multi-master function allows multiple computer
masters to access an RS48 5 slave device at the same time. In this application scenario, you need
to add some TTL to RS485 circuits, or use our ready-made RS485 to network port modules, such as
RS485 TO ETH (B), RS485 TO POE ETH (B),etc.

When used as an MQTT gateway, the device can transparently upload serial port data to the

MQTT server using the MQTT protocol. Supported servers include Baidu Cloud MQTT, Alibaba
Cloud MQTT, China Mobile OneNet platform, etc. Support to parse the collected Modbus RTU or
non- standard serial port data into JSON format, encapsulate it in MQTT data package and upload
it. Support JSON format to upload collected data, automatic data collection, collected data
support Modbus RTU, 645 meter 97 version, 645 meter 07 version, various non-standard RS485
protocols. Users can configure the uploaded data format and JSON keywords with Vircom. When
uploading, it can support MQTT protocol, HTTP POST protocol, HTTP GET protocol, transparent
transmission protocol, and various non-standard network protocols. RS485 TO ETH (B) has
various functions of a powerful IoT gateway, which is very suitable for collecting various RS485
instruments and sensors in the industrial field, including local network collection or uploading to
the cloud server.

UART/RS485 TO ETH (B) can be applied to ：

As a gateway of the Internet of Things as a communication bridge between the device and

the cloud;

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RS485 TO ETH ( B)

2 . FEATURES

2 . 1 . HARDWARE FEATURES

Compact And Easy Integration

Castellated Holes With Immersion Gold Design, Highly Integrated Packaging

Supports Multiple Ways To Be Embedded Into Various Product Applications

Electricity, smart meters and energy consumption monitoring;

Remote monitoring and program downloading of various automated PLCs;

Various configuration software and equipment communication interfaces;

Equipment networking in the field of access control and security;

A typical application connection is shown in Figure 2. The original serial device UART is

connected to the UART port of RS485 TO ETH (B), and UART TO ETH (B) is connected to the
computer through a network cable. The software on the computer establishes a connection with
UART TO ETH (B) through TCP/ IP or virtual serial port. After that, any data sent by the serial
device will be transparently transmitted to the computer software, and the data sent by the
software via the network UAR T TO ETH (B) will also be transparently transmitted to the serial
device

Figure 2 Connection diagram

RS485 TO ETH ( B)

2 . 2 . SOFTWARE FEATURES

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RS485 TO ETH ( B)

2 . 3 . ADVANCED SOFTWARE FEATURES

Support TCP server, TCP client, UDP mode, UDP multicast. As a TCP client, it also supports

TCP server functions. As a TCP server, it supports 30 TCP connections, and as a TCP client, it

supports 7 destination IPs.

The baud rate supports 1200—115200bps, the data bit supports 5-9 digits, and the parity

bit can be five modes: no parity, odd parity, even parity, mark, and space.

It supports the function of sending MAC address on the device connection, which is

convenient for cloud management of the device.

Provide the secondary development kit DLL development library for searching and

configuring equipment on the computer side.

Support Web browser configuration, DHCP dynamic acquisition of IP, DNS protocol to

connect to the domain name server address.

Support cloud remote search for devices, configuration of device parameters, and device

program upgrades.

Support remote viewing of the device's TCP connection status, serial port data sending and

receiving status through software. Virtual serial port supports data monitoring function.

Support Modbus gateway function, support Modbus RTU to Modbus TCP. It can support

storage Modbus, which can automatically collect device data and store it; it also supports

non- storage mode Modbus gateways

Support multi-host function: In the query mode of one question and one answer, the

support network port allows multiple computers to access the same serial device at the

same time.

Support MQTT gateway function.

Support JSON to Modbus RTU and 645 instrument protocol, support HTTP POST, HTTP GET

format to upload data.

Support NTP protocol to obtain network time, which is used for serial port output and the

latter is used for protocol content uploading.

Support custom heartbeat package and registration package function: it can facilitate

communication and device identification with the cloud.

Support the function of password authentication required for TCP connection establishment

to ensure connection security.

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RS485 TO ETH ( B)

3 . TECHNICAL PARAMETER

Appearance

Communication interface

UART

Power supply

3.3V/5V, pin header or pad

Dimensions

L x W x H =3.4cm×2.3cm×1.15cm

Communication interface

Ethernet

RJ45 interface

Serial port

RXD，TXD， GND

Serial port parameters

Baud rate

300~115200bps

Check Digit

None, Odd, Even, Mark, Space

Data bits

5~9 bits

Flow control

optional

software

Protocol

ETHERNET、IP、TCP、UDP、HTTP 、ARP 、ICMP 、DHCP、
DNS

Configuration method

VirCOM tool, WEB browser, device management function
library

Communication mode

TCP/ IP direct communication, virtual serial port mode

Operating mode

TCP server, TCP client (TCP server coexists at the same time), UDP, UDP multicast

Power requirements

Power

3.3V/5V

Environmental requirements

Operating temperature

-40 ~8 5C

Humidity range

5~95% relative humidity

Supports the http method of data submission and distribution. The cloud can directly use

the http GET command to interact with the device' s serial port data.

Table 1 Technical parameters

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RS485 TO ETH ( B)

CONTEN T

d

目录

Figure 2 Connection diagram

....................................................................................................................... 3

2 . 1 . HARDWARE FEATURES.......................................................................................................... 3

2 . 2 . SOFTWARE FEATURES

Table 1 Technical parameters

........................................................................................................... 4

......................................................................................................................6

4 . 1 . HARDWARE DESCRIPTION ................................................................................................... 9

Figure 3 Front view
Figure 4 Power supply, network port
Figure 5 The back of the device

...................................................................................................................................... 9

........................................................................................................ 10

................................................................................. 错误！未定义书签。

4 . 2 . HARDWARE CONNECTION ................................................................................................. 13

4 . 3 . SOFTWARE INSTALLATION ................................................................................................ 13

Table 3 Software description
Figure 7 Device list

..................................................................................................................................... 14

Figure 8 Device parameters
Table 4 Parameter meaning
Add virtual serial port
Enable Modbus TCP function
Modbus TCP as client

Web login interface

................................................................................................................................. 24

....................................................................................................................................25

Web configuration interface

..................................................................................................................... 13

....................................................................................................................... 15

.......................................................................................................................15

................................................................................................................................ 21

.....................................................................................................................24

......................................................................................................................26

5 . 2 . DIRECT TCP/ IP COMMUNICATION MODE

.......................................................................................................................................................... 28

5 . 2 . 1 . TCP CLIENT MODE

.................................................................................................................. 28

5 . 2 . 2 . CLIENT CONNECTS TO MULTIPLE SERVERS ................................................... 29

5 . 2 . 3 . TCP SERVER MODE ................................................................................................ 31

5 . 2 . 4 . ACTING AS BOTH A CLIENT AND A SERVER

................................................... 31

5 . 2 . 5 . UDP MODE................................................................................................................................ 32

6 . 1 . NETWORK PHYSICAL CONNECTION................................................................................ 35

6 . 2 . NETWORK TCP CONNECTION ........................................................................................... 35

6 . 3 . DATA SENDING AND RECEIVING

..................................................................................... 36

6 . 4 . VIRCOM REMOTE MONITORING DATA......................................................................... 36

7 . MODBUS ADVANCED FUNCTIONS ............................................................................................ 38

7 . 1 . ENABLE MODBUS GATEWAY

............................................................................................ 38

7 . 4 . MULTI - HOST FUNCTION.....................................................................................................41

7 . 6 . MODBUS UNDER MULTI - DESTINATION IP ................................................................... 44

8 . REGISTRATION PACKAGE AND HEARTBEAT PACKAGE .......................................................44

8 . 1 . 1 . SEND MAC ADDRESS ON CONNECTION

8 . 1 . 2 . REALCOM AGREEMENT

.........................................................................................................45

.......................................................... 45

8 . 1 . 3 . CUSTOM REGISTRATION PACKAGE .................................................................. 46

8 . 1 . 4 . CONFIGURATION FILE

8 . 2 . HEARTBEAT PACKAGE

........................................................................................................... 47

......................................................................................................... 48

8 . 2 . 1 . IMPLIED HEARTBEAT ............................................................................................................. 48

8 . 2 . 2 . REALCOM PROTOCOL

........................................................................................... 49

8 . 2 . 3 . CUSTOM HEARTBEAT PACKAGE........................................................................ 49

9 . REMOTE DEVICE MANAGEMENT

.............................................................................................. 49

RS485 TO ETH ( B)

7. 4 . Multi-host function

7.5 . Multi-host parameters

7.6. Modbus under multi- destination IP

............................................................................................................

.......................................................................................................

.................................................................................

8 . Registration package and heartbeat package

8. 1 . Registration package

.........................................................................................................

8. 1. 1 . Send MAC address on connection

8. 1 .2 . Realcom Agreement

8.1 . 3. Custom registration package

8. 1 . 4 . Configuration file

8.2. Heartbeat package

.............................................................................................................

8. 2 . 1 . Implied heartbeat

8.2.2. REALCOM protocol

8.2 . 3 . Custom heartbeat package

9 . Remote device management

10 . MQTT and JSON

.....................................................................................................................

11. firmware upgrade method

..............................................................................................

................................................................................

...................................................................................................

..................................................................................................

................................................................................................

...................................................................................

.................................................................................................

...................................................................................................

......................................................................

.......................................................................

39

40

42

4 2

43

43

43

4 4

45

46

46

47

47

4 7

49

4 9

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RS485 TO ETH ( B)

4 . INSTRUCTIONS FOR USE

The UART TO ETH (B) module is used to realize the two-way transparent transmission of
data from the serial port to the Ethernet port. The user does not need to care about the specific
details, and the module completes the protocol conversion inside. The serial port side is the
serial port level data, and the Ethernet port side is the network data packet. You can specify the
work details through simple settings. The parameters can be set through the built- in webpage or
through the setting software, and the settings can be saved forever.

This chapter is the user manual for the product UART TO ETH (B). It is recommended that
users read this chapter systematically and follow the instructions to get a systemic

understanding of this product. Users can also choose the chapters they are interested in to read
according to their needs. For specific details and instructions, please refer to the subsequent
chapters.

In addition to this manual, we also provide configuration software and other materials
based on this product for user design reference download link :

http://www.waveshare.com/wiki/UART_TO_ETH_( B)_

4 . 1 . HARDWARE DESCRIPTION

Figure 3 Front view

The front view of the U A R T TO ETH ( B) serial server is shown in the figure above.

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RS485 TO ETH ( B)

UART TO ETH (B) Pinout

Pin

Model

Description

5V

Power

5V Power Input

3.3V

Power

3.3V Power Input

GND

Ground

Ground

RST

Reset

Reset pin, low active. It is recommended to use

max811reus or a similar reset chip. Noise can be

filtered by a 0.1u capacitor. Low-level minimum time

100ns.

TXD

OUT

Serial data transmitting pin of the module, 3.3V TTL

level, can be connected to RXD of user MCU.

RXD

IN

Serial data receiving pin of the module, 3.3V TTL level,

can be connected to the user MCU's TXD.

DEF

IN

When the parameter is reset to 0 and held for more

Figure 4 UART TO ETH (B)

RS485 TO ETH ( B)

than 1 second, the module will restart with the default

IP of 192.168.1.254, static IP mode, 255.255.255.0

gateway, and 192.168.1.1 gateway. You can also set

your own reset parameters with the param.txt

configuration file.

RUN

OUT

Working indicator, the chip works properly, and will

output a square wave with a period of 2 seconds. You

can connect a 4.7K resistor and then connect the LED

to the ground and the LED is on indicating the chip

has been working.

EN

OUT

The 485 transmit controller, normally 0, becomes 1

when the module sends data to the serial port. It can

be connected directly to the TXD_EN pin of the

MAX485 chip.

RTS

OUT

Hardware flow control output. After the flow control is

set to CTS/RTS, DTR/DSR, RTS=0 normally, if RTS=1, it

means the module can't receive data and the user

MCU should stop sending data to the module.

CTS

IN

Hardware flow control input, when the chip is

configured for CTS/RTS, DSR/DTR serial mode, only

when CTS=0, the chip serial port will output data to

the outside.

GND

Ground

Ground

LINK2

OUT

When it is 0, it indicates that the module RJ45 network

cable is connected.

ACT

OUT

Data indicator. When it is 0, it indicates that there is

data being sent and received at the serial port. But

when there is data, this pin will jump between 0 and 1.

ACT=1, which cannot be used as a flag for no data

communication.

LINK

OUT

TCP connection indicator. When it is 0, the module has

established TCP/UDP connection with the network

server, and the module can send and receive data

normally. If the network cable is unplugged at this

RS485 TO ETH ( B)

time, the LINK will change to 1.

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RS485 TO ETH ( B)

4 . 2 . HARDWARE CONNECTION

Generally speaking, the serial server only needs to be connected to the power supply, serial

port, and network cable.

The network port is connected to a common network cable, which can be directly connected

to a computer or connected to the network through a switch.

4 . 3 . SOFTWARE INSTALLATION

name of software

illustrate

VirCom

Chinese version configuration software

VirCom_ en

English version configuration software

Virtual- serial- port

Virtual serial port software

4 . 4 . PARAMETER CONFIGURATION

Vircom can be used to configure parameters such as device IP and create virtual serial ports.
If you do not need the virtual serial port function, you can only download the

installation- free version of the configuration software.

Table 3 Software description

After Vircom is installed and the device hardware is connected, run the software as shown

in the figure, and then click "Device Management" as shown in the figure. Using Vircom, you can

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RS485 TO ETH ( B)

search and configure device parameters in different network segments, which is very convenient,
as long as the device and the computer running Vircom are under the same switch.

Figure 6 Vircom main interface

Figure 7 Device list

See all currently online devices from the device list. Click " Edit Device" to configure the

parameters.

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RS485 TO ETH ( B)

parameter name

Ranges

meaning

Virtual serial

port Unused, created
virtual serial port

You can bind the current device with a created
virtual serial port. Please add a COM port in the
"Serial Port Management" on the main interface
first.

Device model

Only display the model of the core module

Device name

Any

You can give the device an easy- to-read name, up
to 9 characters long

Device ID

Factory unique ID, cannot be modified.

Firmware

version

The firmware version of the core module
Supported

Refer to Table 5 Supported functions of the

Figure 8 Device parameters

In this interface, the user can set the parameters of the device, and then click "Modify
Setting" , the parameters will be set to the flash of the device, and they will not be lost after
power failure. At the same time, the device will automatically restart.

The main configuration parameters here are: baud rate, data bit, parity bit in serial port
settings; IP address, subnet mask, gateway in network settings; sometimes according to
computer software, you also need to configure the work of the serial server model.

The detailed meanings of other parameters are as follows:

Table 4 Parameter meaning

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RS485 TO ETH ( B)

functions

device

IP mode

static, DHCP

users can choose static or DHCP (dynamically
obtain IP)

IP address

The IP address of the serial server

Port

0~65535

The listening port when the serial port server is in
TCP Server or UDP mode. As a client, it is best to
specify the port as port 0, which helps to increase
the connection speed. When port 0 is used, the
system will randomly allocate a local port. The
difference between this and non-zero port is: (1)
When the local port is 0, a new TCP connection
will be established with the PC when the module
restarts, the old TCP connection may not be
closed, and the device may have multiple fakes.
connect. Generally, the host computer hopes to
close the old connection when the module
restarts; specifying a non- zero port will close the
old connection. (2) When the local port is 0, the
time for TCP to re- establish the connection is
faster. When the serial port server is in TCP client
mode, it also acts as a TCP server to monitor
connections on the port. At the same time, the
local port number used by the TCP client to
connect to the server is "port+1" .

Working mode

TCP server mode,
TCP client mode,
UDP mode, UDP
multicast

When set to TCP server, the serial port server
waits for the computer to connect; when set to
TCP client, the serial port server actively initiates a
connection to the network server specified by the
destination IP.

Subnet mask

For example:

255.255.255.0

must be the same as the subnet mask of the local
LAN.

Gateway

For example:

192.168.1.1

must be the same as the local LAN gateway.

Destination IP or

domain name

In TCP client or UDP mode, data will be sent to
the computer indicated by the destination IP or
domain name.

Destination port

In TCP client or UDP mode, data will be sent to
the destination port of the destination IP.

Baud rate

300 、600、1200、2400、
4800、7200 、9600、
14400 、19200 、28800、
38400 、57600 、76800、
115200、230400、460800

Serial port baud rate

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Data bits

5、6、7、8、9

Check Digit

None, Even, Odd, Mark,
Space

Stop bit

1、2

Flow control

No flow control,
Hard flow control
CTS/ RTS, hard flow
control DTR/ DCR, soft
flow control XON/XOFF

only valid for RS232 serial port

DNS server

When the destination IP is described by a domain
name, this DNS server needs to be filled in.
Server IP. When the IP mode is DHCP, there is no
need to specify DNS
Server, it will be automatically obtained from the

DHCP server.

Destination
mode

In static and dynamic

TCP client mode: After using the static destination
mode, the device will automatically restart the
device after 5 consecutive failures to connect to
the server.

Conversion
agreement

NONE 、
Modbus TCP<-> RTU、
Real_COM

NONE means that the data forwarding from the
serial port to the network is transparent;
Modbus TCP<- >RTU will directly convert Modbus
TCP protocol to RTU protocol, which is convenient
to cooperate with Modbus TCP protocol; RealCOM
is designed to be compatible with the old version
of REAL_COM protocol. It is a protocol of virtual
serial port mode, but it uses virtual serial port. At
this time, it is not necessary to choose the
RealCom protocol.

Keep-alive

timing time

0~255

Heartbeat interval. (1) When the selection is
1~255, if the device is in the TCP client working
mode, it will automatically send TCP heartbeats
every "Keep Alive Time". This can ensure the TCP
validity of the link. When set to 0, there will be no
TCP heartbeat. (2) When it is set to 0~254, when
the conversion protocol is selected as REAL_COM,
the device will send a data with a length of 1 and a
content of 0 every keep- alive timing time, which
realizes the heartbeat mechanism in the Realcom
protocol. When set to 255, there will be no
realcom heartbeat. (3) When it is set to 0~254, if
the device works as a TCP client, the device will
send device parameters to the destination

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computer every keep- alive time. When it is set to
255, there will be no parameter sending function,
which can realize remote device management.

Disconnection
reconnection

time

0~255

0~255 When in TCP client mode, when the
connection is not successful, each "disconnection
reconnection time" will re- initiate TCP connection
to the computer. It can be 0~254 seconds. If you
set 255, it means that you will never reconnect.
Note that the first TCP connection (such as
hardware power- on, device restart via Vircom
software, no data light) will generally be carried
out immediately, and only after the first
connection fails will it wait for the " disconnected
reconnection time" and try again, so
" Disconnected reconnection time" will not affect
the connection establishment time of the network
and the server under normal conditions.

Web access port

1~65535

The default is 80

Adress of

multicast

Used in UDP multicast

Enabling the
registration
package

When the TCP connection is established, the
registration package is sent to the computer. After
enabling the registration package, the realcom
protocol must be selected. Support TCP server and
TCP client mode.

Data packet
length

1~1400

1~1400 One of the serial framing rules. After the
serial port server serial port receives the length of
data, it sends the received data to the network as
a frame.

Data packet

interval

0~255

Name

Description

Domain Name

System

The destination IP can be a domain name (such as the www server
address at the beginning).

REAL_ COM Protocol

A non-transparent serial port server protocol, suitable for multiple
serial port servers to bind virtual serial ports through the Internet.
Because the MAC address of the device is contained in the protocol, it
is helpful for the host computer to identify the device. Under normal

The functions supported by the device are explained as follows:

Table 5 Functions supported by the device

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circumstances, it can not be used.

Modbus TCP to RTU

can be converted from Modbus TCP to RTU . It also supports
multi- host function.

Serial port
modification

parameters

Support serial port AT commands to configure and read device
parameters.

Obtain IP
automatically

support DHCP client protocol

Storage expansion EX
function

Subsequent expansion

Multiple TCP
connections

When acting as a TCP server, it supports more than 1 TCP connection.
IO port control

Supports any custom commands to control 8 IO outputs.

UDP multicast

UDP multicast

Multi- destination IP

As a TCP client, it supports simultaneous connection to 7 destination
IPs.

4 . 5 . TCP COMMUNICATION TEST

After configuring the device parameters, you can use the serial port tool and TCP debugging

tool to test the TCP connection communication.

Figure 9 Schematic diagram of TCP communication

The serial port server's serial port to network port, network port to serial port data

transparent forwarding function.

Assuming that the COM port (USB TO TTL) of the PC is connected to the serial port of the
serial server, then open the serial debugging assistant window and open the corresponding COM
port, as shown in the figure below:

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Figure 10 SSCOM1: USB TO TTL transceiver interface

In addition, open one more serial port debugging assistant window and use it as a TCP client
mode. Fill in the destination IP as the IP of the serial server (currently 192.168.1.200) and the
destination port as 4196, and then click the "Open" button, as shown in the figure below:

Figure 11 SSCOM2: TCP Client transceiver interface

Enter "TCPClient : Waveshare Test" in the serial debugging assistant SSCOM2 set as
TCPClient and click send, then the data will be transferred to the RS485 interface through the
serial server's network port, and then sent to the USB TO RS485 , and then displayed in the serial
debugging assistant SSCOM1 Come out; conversely, input "USB TO TTL: Waveshare Test" in
SSCOM1, and click Send to send to SSCOM2 and display it.

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4 . 6 . VIRTUAL SERIAL PORT TEST

The SSCOM2 in the figure communicates directly with the serial server through TCP. In
order to allow the user to communicate with the serial server as well as the serial software that
has been developed by the user, a virtual serial port needs to be added between the user
program and the serial server. As shown in the figure, Vircom and the user program run on the
same computer, and Vircom virtualizes a COM port, so that this COM port corresponds to the
serial server. When the user program opens the COM communication, it can be sent to the user
serial device through the Vircom serial server. The following demonstrates this operation step:

Figure 12 Application example of virtual serial port

Click "Serial" on the main interface of Vircom, then click "Add", and choose to add COM2,
where COM5 is a COM port that does not exist in the computer.

Add virtual serial port

Then enter the device management, and double-click the device that needs to be bound to
COM2. As shown in the figure, select COM2 in the "Virtual Serial Port" list in the upper left
corner. Then click "Modify Setting", and then click "Restart Dev". And return to the main
interface of Vircom. You can see that COM2 has been connected to the device with IP

192.168.1.200. At this time, COM2 can be used instead of SSCOM2 for communication.

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The virtual serial port has been connected

Open SSCOM to simulate the user' s serial port program, open COM2 (the virtual serial port
above), open another SSCOM to simulate a serial device, and open COM3 (hardware serial port).
At this time, the COM2 sending data link is as follows: COM2 — "Vircom — "Serial server network

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4 . 7 . MODBUS TCP TEST

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

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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Enable Modbus TCP function

If the user's Modbus TCP software is used as a slave (Slave), you need to change the working
mode to client based on the selection of the conversion protocol, and change the destination IP
to the IP of the computer where the Modbus TCP software is located, and the destination port is
502, as shown in the figure blow.

Modbus TCP as client

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4 . 8 . WEB CONFIGURATION

Using Vircom, you can search and configure device parameters in different network
segments. Web configuration requires that the computer and serial server are in the same IP
segment, and the IP address of the serial server must be known in advance. But the Web
configuration can be done on any computer without Vircom.

1. Enter the IP address of the serial port server in the browser, for example http://192.168.1.200,

and open the following web page:

2. Enter the password in Password : there is no password set by default in the factory state, and
the password needs to be set through Modify Web Login Key to take effect.

Web login interface

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5 . WORKING MODE AND CONVERSION AGREEMENT

Web configuration interface

3. In the web page that appears, you can modify the serial server parameters. For related

parameters, please refer to Table 4 for the meaning of the parameters.

4. After modifying the parameters, click the " Submit" button.

Different serial server working modes and conversion protocols can be selected in different

application occasions, so that it can be used more stably and reliably, which will be described in

detail below.

The use of serial port server is basically divided into two types: with virtual serial port and
non-virtual serial port, as shown in Figure 9 TCP communication diagram and Figure 12 the
function of virtual serial port. The user software with virtual serial port that needs to be docked
is a serial interface ( COM port), that is, the user software and user equipment are serial ports;
the user software of the non- virtual serial port mode communicates directly with TCP/ IP, but the
user equipment is still a serial port.

In the non-virtual serial port mode, the "conversion protocol part" is divided into three
modes: transparent transmission, Modbus TCP to RTU and Realcom protocol. If the user
software is a fixed protocol Modbus TCP protocol and the lower computer is Modbus RTU, you

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NO.

Virtual

serial

port

Device

working

mode

Conversion protocol

Description

1

Use

TCP server

None

Suitable for occasions where user
software opens the COM port to
actively collect data.

2

Use

TCP client

None

Suitable for occasions where the
device actively sends data. If you
choose a TCP server, the problem
that the device cannot reconnect
after disconnection may occur.

3

Do not
use

TCP server

Modbus TCP to RTU

Applicable to the user software is
Modbus TCP, and the user device is
Modbus RTU. And Modbus TCP is
the master station.

4

Do not
use

TCP client

Modbus TCP to RTU

Applicable to the user software is
Modbus TCP, and the user device is
Modbus RTU. And Modbus RTU is
the master station.

5

Use

TCP client

Realcom protocol

Multi-serial server as TCP client, and
use virtual serial port, it is best to
use Realcom protocol.

6

Do not
use

TCP client

None

Applicable to a large number of
devices connected to a cloud. And
in general, the cloud is a public IP
server on the Internet.

7

Do not
use

TCP server

None

Suitable for devices and computers
in the same local network,
monitoring locally, without
cross- Internet communication.

5 . 1 . VIRTUAL SERIAL PORT MODE

need to select Modbus TCP to RTU mode; Realcom protocol is currently only used in a

multi-serial server as a TCP client to connect to a server, and the virtual serial port is used on the

server. Time to use.

The usage is summarized as follows:

Table 6 Network configuration mode

If the user software uses the COM port for communication, it must use the virtual serial port

mode. Including some PLC software, configuration software, instrument software, etc.

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5 . 2 . DIRECT TCP/ IP COMMUNICATION MODE

If Modbus TCP protocol conversion and virtual serial port are not needed, the user software
may directly communicate with the serial port server' s network port for TCP/ IP communication,
and the serial server converts TCP/ IP data into serial data and sends it to the serial device.

Generally, users of this kind of usage develop their own upper computer network
communication software, which integrates the analysis of the device's serial communication
protocol. This method is more flexible and efficient than the virtual serial port. Correspond to ⑥
and ⑦ in Table 6.

The section "4.5 TCP Communication Test" mainly briefly describes how to communicate
when the serial port server is used as a TCP server. Here will describe how TCP client, UDP mode,
and multiple TCP connections communicate with computer software. Among them, the
computer software takes SSCOM (serial port debugging, software that imitates user TCP/ IP
communication) as an example.

The serial server complies with the standard TCP/ IP protocol, so any network terminal that
complies with this protocol can communicate with the serial server. For two network terminals
(here, the network debugging tool and the serial server) to be able to communicate, their
parameter configuration must be paired.

Look at whether the monitoring computer and equipment are in the local network :

a) If the computer is a public IP server leased on the Internet, the device must use the TCP
client method to connect the device to the server. At this time, you can choose ② and ⑤ in
Table 6, if it is a multi-serial server, you must choose ⑤ .

b) If they are all on the local network (can ping each other), it depends on whether the host

computer actively inquires or the device actively sends data. If the device actively uploads, the

② method of using the device as a TCP client must be used, otherwise the ① method can be

selected.

5 . 2 . 1 . TCP CLIENT MODE

There are two working modes in TCP mode: TCP server and TCP client. Regardless of which

mode is adopted, one must be the server and the other must be the client. After that, the client

can access the server, both of which are either client or service. Communication cannot be

achieved at the end.

When the serial port server is used as a client, there must be three corresponding
relationships, as shown in Figure blow. (1 ) Working mode correspondence: The working mode of
the serial port server is the server mode of the client corresponding to the network tool, ( 2 ) IP
address correspondence: The destination IP of the serial port server must be the IP address of

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the computer where the network tool is located, ( 3 ) Port correspondence: The destination port

of the serial server must be the local port of the network tool. After this setting, the serial server

can automatically connect to the network tool, and data can be sent and received after the

connection is established.

Serial server as a client

5 . 2 . 2 . CLIENT CONNECTS TO MULTIPLE SERVERS

When the serial server is used as a TCP client, it can connect to 7 destination IP addresses at

the same time, and the data sent by the serial port will be sent to 7 destination IPs at the same

time. If there are not so many servers, leave the rest of the destination IP vacant. The method of

use is as follows:

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Figure 14 The first destination IP and port

Figure 15 The remaining 2~7 IPs and ports

The first IP is set in the device setting interface as shown in Figure 1 4. The first IP can be a
domain name. For the remaining 2~7 destination IPs, click the "More Advanced Setting... " button
in the device setting interface to open More Advanced Settings for setting.

After all 7 destination IPs are set up, they can be connected automatically. If they are not
connected, they will wait for the " Reconnect Time" time and then reconnect repeatedly.

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5 . 2 . 3 . TCP SERVER MODE

When the serial port server is used as the server, there are also three corresponding
relationships, as shown in Figure 16 , which will not be explained here. After setting, click the
open button of the network tool to establish a TCP connection with the serial server, and then
you can send and receive data after the connection is established.

Figure 16 Serial port server as TCP server

When the serial port server is used as a server, it can accept 3 0 TCP connections at the same
time. The data received by the serial port will be forwarded to all established TCP connections. If
you need to realize that data is only sent to the TCP that has recently received network packets,
you need to enable the multi-host function, please refer to 7. 4 Multi-host function.

5 . 2 . 4 . ACTING AS BOTH A CLIENT AND A SERVER

The serial port server supports the ability to accept TCP connections even when the device
is in the TCP client mode, that is, it also has the TCP server function.

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Figure 17 Acting as both a client and a server

By default, when using Vircom for configuration, if you change the working mode to " TCP
client", the port (that is, the local port) will automatically become 0 (0 means a free port is
randomly selected) . In order to be able to support the TCP server mode, the computer software
must know the local port of the device, so a value needs to be specified here. As shown in Figure
17, the computer software can now connect to the 1024 port of 192.168.1.200 for
communication, and the device will also act as a client Connect to the 1024 port of
1 92.16 8. 1.18 9. It should be noted that since the local port 10 24 is occupied by the server, the
local port when used as a client is "port+1", that is, the software on 192. 168.1.189 sees that the
incoming port of the device is 1024+1 =1025.

5 . 2 . 5 . UDP MODE

In UDP mode, the parameter configuration is shown in Figure 18. The left side is the
configuration of the serial server in Vircom, and the right side is the setting of the serial
debugging tool SSCOM. First of all, both must be UDP working modes. In addition, indicated by
the red arrow, the destination IP and destination port of the network tool must point to the local
IP and local port of the serial server. As indicated by the blue arrow, the destination IP of the
serial server must be the IP address of the computer where the network tool is located, and the
destination port of the serial server must be the local port of the network debugging tool. Only
after these network parameters are configured can two-way UDP data communication be
ensured.

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5 . 3 . DEVICE COUPLET WAY

Figure 18 UDP mode parameter configuration

If the host computer is not an SSCOM program or a virtual serial port, but two devices are
connected through a network port, the configuration method is similar. First, the user needs to
connect two devices and computers to the same local area network. Vircom is running on this
computer. The purpose of connecting to the computer is only for configuration. After the
configuration is completed, the computer does not need to be connected.

Click on Vircom' s device management to find these 2 devices, as shown in Figure 20 . Then
click " Edit Device" to configure the device. Device couplets can be divided into TCP couplets and
UDP couplets. If it is TCP couplet, the parameters of the two devices are shown in Figure 1 9. The
parameters shown by the arrows must correspond, just like the corresponding way of connecting
with a PC. After the TCP connection is successful, you can view the connection status by
returning to the "Device Management" dialog box, as shown in Figure 20. If the status of the two
devices is both "Connected", it means that the TCP link between the two devices has been

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established.

Figure 19 TCP device pairing parameter configuration

Figure 20 TCP device pairing parameter configuration

If it is couplets in UDP mode, the configuration parameters are shown in Figure 21 , and the
parameters corresponding to the arrows must be one- to- one correspondence. UDP couplet does
not need to check the connection status as long as the parameter configuration is correct, the
sent data will be automatically sent to the designated device.

Figure 21 UDP device pairing parameter configuration

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6 . EQUIPMENT DEBUGGING

6 . 1 . NETWORK PHYSICAL CONNECTION

The serial server can use a crossover cable or a direct- connected network cable to connect

to the switch or directly connect to the computer network port.

After the connection is established, the first step is to check whether the Link light is green,

otherwise, please check whether the network cable is connected.
6 . 2 . NETWORK TCP CONNECTION

Finally, I need to remind that if the device is connected, in addition to the network port
parameters set according to the above, the correct serial port parameters must also be set.
Mainly, the baud rate of the serial server needs to be consistent with the baud rate of the user's
device. After this setting, the user equipment can send data to each other through the serial
ports of the two serial port servers.

When the device is used as a way to dynamically obtain IP, it cannot be directly connected
to the computer network port. Because there is no DHCP server available ( generally a DHCP
server is a router in the LAN). So please specify the IP when connecting directly. At the same time,
the computer also needs to specify a fixed IP.

Configured in the same network segment

Whether it is directly connected or through a switch, when configured as a static IP, the
device and the computer need to be in the same network segment ( unless it is cross- gateway
communication) , as shown in Figure above.

Since Vircom supports searching and configuration across network segments, the IP address
that can be searched but cannot be communicated is generally not configured properly. In this
case, you can use Vircom to configure the device in the same network segment.

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6 . 3 . DATA SENDING AND RECEIVING

When the Link light turns blue, data can be sent and received between the software and the
serial server. At this time, if the software sends a data, the Active light will turn green, and the
duration will generally be at least 1 second. The data will also be output from the serial port of
the serial server, but whether the output data is correct depends on whether the correct serial
port parameters (baud rate, data bit, stop bit, parity bit) are configured. The serial device
generally responds to the correct command issued. Once there is a reply (the serial port sends
data to the network port), the Active will turn blue. Otherwise, please check the serial port
parameters or whether the serial cable is connected.

In order to facilitate remote debugging, Vircom also supports remote viewing of data sent
and received. As shown in Figure 22, TXD is the amount of data sent by the serial port server
serial port. When the device list is refreshed, if this value changes, it indicates that there is data
sent. The Active light will also be green; if you see the value of RXD changing, it indicates that the
serial device has returned data, and Active is blue.

6 . 4 . VIRCOM REMOTE MONITORING DATA

After configuration, use the steps of 4.5 TCP communication test or 4. 6 virtual serial port
test, you can see that the Link light turns blue when the TCP connection is established. The blue
link light can also be seen through Vircom. For example, in the device management list, if the TCP
connection column is "established", it means the link light is blue, as shown in Figure 22. This can
facilitate remote diagnosis.

Figure 22 Connection status and data receiving and sending status

In the case of using a virtual serial port, Vircom supports real-time capture of the data sent

and received by the virtual serial port. It is convenient for users to debug the system, and the

method of use is as follows:

It is assumed that the communication of the virtual serial port has been established

according to the method of 4.6 virtual serial port test. Now need to monitor the data through the

virtual serial port. Open Vircom' s menu/Config/software setting/ open the Vircom configuration

dialog box.

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Figure 31 Enable Virocm monitoring

Tick in front of the three options: open monitoring, hexadecimal monitoring mode, and
display data sending and receiving time, as shown in Figure 23 . Then click OK. Assuming that data
has been sent and received before, now select a virtual serial port to be monitored in the main
interface, and then select Menu/View/ Monitor, as shown in Figure 24.

Figure 32 Open Virocm monitoring

From the opened dialog box, you can see the instructions issued by the host computer and

the instructions returned by the device, as shown in Figure 25. This function can facilitate on-site

communication debugging.

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7 . MODBUS ADVANCED FUNCTIONS

The serial port server with Modbus gateway function does not have station address and
registers. It is a communication bridge. It will generate Modbus according to the Salve ID,
function code, register number and number of registers in the Modbus TCP command sent by
the user software to the Modbus gateway. RTU designates and outputs from the serial port.
Think of it as a protocol "translator".

7 . 1 . ENABLE MODBUS GATEWAY

Figure 33 Monitor sending and receiving data

First of all, the serial port server should support Modbus gateway, that is, the " Modbus TCP

to RTU" function in Table 5 Device Supported Functions in the Device Settings dialog box should

be ticked.

By default, the serial server is in normal transparent transmission mode. If you need to
switch to Modbus gateway mode, please select the option "Modbus TCP Protocol" in
"Conversion Protocol". After that, the device automatically changes the " port" parameter to 502
(the port of the Modbus server). Then the Modbus gateway is enabled.

If the serial port RTU device is used as a slave station, the host computer Modbus TCP
software connects to port 502 of the Modbus gateway. At this time, the Modbus gateway needs
to work in TCP server mode; if the serial port RTU is used as the master station, the Modbus
gateway works as a TCP client and the destination IP Fill in the IP of the computer where the
Modbus TCP software is located, and the destination port is generally 502 .

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7 . 2 . STORAGE MODBUS GATEWAY

This product can save the content of the read register inside the gateway, so that the speed
of Modbus TCP query can be greatly improved, and the performance is even better when it
supports multi- host access.

As shown in Figure 26: The general Modbus TCP data flow direction is (1) (2) (3) (4). That is,
the Modbus TCP command is first converted into the corresponding command of Modbus RTU,
and then the device responds to the Modbus RTU command to the Modbus gateway, and then
the Modbus gateway is converted to Modbus TCP again and sent to the monitoring host
computer.

We know that Modbus TCP is network communication, and the transmission speed is very
fast. Generally, it can respond within 3ms, while Modbus RTU is RS485, which generally has a
speed of 9600bps. It usually takes at least 30ms to send and return a command. The query
response time of such ordinary non-storage Modbus gateways is relatively long. In addition, if
there are a lot of host computers at the same time to query data at the same time, then the
serial port will be congested. If the network is like an expressway, and the serial port is like a

Figure 26 Working Mode of Storage Modbus Gateway

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single-plank bridge, then the original method is to pass the traffic flow of the expressway on the

single- plank bridge.

The register-savi ng Modbus gateway solves the above problems. It can temporarily save the
register data obtained by the query in the Modbus gateway, so that when the Modbus TCP query
comes, the Modbus gateway can immediately return the command, which truly brings out the
fast characteristics of Modbus TCP. On the other hand, the serial port server can take the
initiative to send instructions from the serial port to automatically update the contents of the
currently saved register data, and save a copy of the latest register value.

In addition, this serial server is a fully automatic configuration- free Modbus gateway, users
do not need to configure the required register address, function code, slave address, etc. The
serial server will automatically recognize and dynamically add these registers according to the
Modbus TCP commands sent from the network port.

RS485 TO ETH (B) can show good response speed when monitori ng by multiple computers.
No matter what baud rate of the serial port is, it can generally reply data to the host within 3ms.
And showed a good real- time update speed of serial port data.

The register-savi ng Modbus gateway is a real Modbus TCP to Modbus RTU . It really takes

advantage of the fast speed of Modbus TCP and the ability to query by multiple hosts at the

same time.

Note that when the serial port server is used as a TCP client, it does not have the storage
type function and will automatically switch to the non- storage type.

The characteristics of storage Modbus are listed below:

1 . The first Modbus TCP query command is non-storage type. Because you must wait for the

RTU device to return data slowly before returning the register content to the network port.

2. If a specific command is no longer inquired by the host computer on the network side
within 5 seconds, this command will be automatically deleted and no longer sent to the RTU
device from the serial port.

3. At present, it can store 10K Modbus cache. For ordinary single-register query, about 500

instructions can be stored at the same time.

4. When multiple commands are being queried at the same time, they are sent in order. The

first command sends the first command response and waits for 485 anti-collision time (refer to

the multi- host section). The second command sends... Return to the first command after the last

command has been answered.

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7 . 3 . DISABLE STORAGE FUNCTIONS

Although the storage Modbus has a faster response speed, some users do not want the RTU
device to receive a large number of query commands, which affects the internal processing
speed of the instrument. The storage function can be turned off at this time.

The method to disable the storage type is to click the " More Advanced Settings" button in
the "Parameter Configuration" dialog box, remove one support and one enable as shown in
Figure 27 and click OK. Then go back to the device settings and click Modify settings.

Note that when using the Web method to configure the conversion protocol, the default is a

non- storage Modbus gateway.

Figure 27 Disable storage function

7 . 4 . MULTI - HOST FUNCTION

As shown in Figure 27, "Enable RS485 Multi- Host" and "Enable RS485 bus conflict detection"
are multi- host functions. They are generally enabled and disabled at the same time. After
enabling, let the device whose conversion protocol is Modbus TCP has the storage Modbus
gateway function, otherwise it is a non- storage Modbus gateway; if the conversion protocol is
None, generally the user-defined RS485 protocol can also have serial devices accessed by
multiple hosts at the same time This function cannot be achieved in a pure RS485 network,
because multiple master stations sending at the same time will cause conflicts on the RS485 bus.
The multiple hosts of this serial server can "coordinate" the RS48 5 bus to achieve the purpose of
multi- host access.

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7 . 5 . MULTI - HOST PARAMETERS

Figure 28 Multi-host function demonstration

As shown in Figure 28, in the normal mode, when two hosts: host A and host B are
connected to the serial server at the same time, host A sends (1) command, RS485 device
receives (2) command, RS485 device returns (3) ) Command, but the serial port server will send
(4) to host A and (5) to host B at the same time. Since the host B did not send the query, but it
also received the response command (5 ), the host B may generate a communication abnormal
error. In the multi-host mode, there will only be instructions (4) but not instructions (5), because
the serial server will automatically remember the host that needs to be returned, and only return
the instructions to the most recent communication host, and the query of host A will only reply
to A, host B queries and replies to host B.

Another function is that in the normal mode, when the host A and the host B send data at
the same time, the combination of instructions will be generated on the RS485 bus, so that it
cannot be recognized normally; in the multi-host mode, the serial server can schedule A and B to
use the bus. Prioritize the conflict problem of simultaneous access by multiple machines in an
effective way.

When the conversion protocol is "None", the multi-host function is not enabled by default.
When you need to enable multiple hosts, please click "More Advanced Settings" in the device
configuration dialog box, and then check " RS48 5 multi-host support".

The meanings of "Enable RS485 Multi- Host " and "Enable RS485 bus conflict detection" are

introduced as follows.

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Figure 37 RS485 multi-host support

The RS48 5 command response timeout time is: the maximum time interval from the
beginning of sending this command to receiving the response from the serial server serial port.
The time to fill in should be greater than the actual maximum time interval. Because once it is
determined to be timed out, the next command will be sent.

Figure 30 RS485 anti-collision idle time

RS48 5 bus conflict time: indicates how many milliseconds the serial server waits after
receiving the reply of the first command before sending the second command. This parameter
actually defines the speed of the command rotation. The value is recommended to be more than
20ms. The parameter "maximum waiting time 3 seconds" generally does not need to be
modified.

When the user uses Vircom to select the conversion protocol as " Modbus_TCP Protocol",
Vricom will automatically check the above two enabling boxes (unless the user manually enters
the advanced option to remove it), and the above two times will also be automatically

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7 . 6 . MODBUS UNDER MULTI - DESTINATION IP

As shown in Figure 28, if the serial port device (RTU device) is used as the master station
and the network port device (Modbus TCP device) is used as the slave station, and there are
multiple network port slave devices at the same time. At this time, you can use the method
described in 5.2.2 Client Connecting Multiple Servers to let the serial port server as a client
connect to these multiple network port devices at the same time.

The function that needs to be realized at this time is: when the serial port RTU sends a
command, it can be sent to multiple network port devices, the network port device recognizes
whether to send it to itself through the Slave ID field, and only the network port device
corresponding to the Slave ID responds. After the network port response is sent to the serial
server, it is converted into an RTU command and output from the serial port to the RTU device.

At this time, it should be noted that it is necessary to remove the two checkmarks shown in
Figure 30 as "RS485 bus anti-collision time" and Figure 29 as "RS485 command response timeout
time". Otherwise, the above forwarding function cannot be realized. Another application method
is: Although the serial port server is connected to multiple network port devices as a Client, the
RTU device is not the master station, and the network port device still sends it first, and the RTU
device responds (as a slave station). At this time, the "RS485 bus anti-collision time" and "RS485
command response timeout time" still need to be checked, so that multiple hosts can access one
RTU device at the same time.

8 . REGISTRATION PACKAGE AND HEARTBEAT PACKAGE

configured according to the baud rate . However, if the user's Modus command is relatively long
or the conversion protocol is " None", these two parameters need to be configured manually.

The following describes the recommended settings of the above parameters:

1. Figure 30 shows the "RS485 bus anti-collision time". Generally, it can be set to twice the

"Packet Interval" in the lower right corner of the parameter configuration interface, but the

minimum should not be less than 20.

2. Figure 29 shows the "RS485 command response timeout time", which is generally
determined according to the length of the back and forth response command. If the sending
command is N bytes and the response is M bytes, the recommended value is: "Packet interval"
× (N+M+5)+100.

The registration package and the heartbeat package are a function suitable for

communication between the device and the cloud software.

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8 . 1 . REGISTRATION PACKAGE

The definition of the registration package is that when the computer software and the serial
server module (herei nafter referred to as the module) establish a TCP connection, the module
will first send a string of codes to the software, so that the software can know which module is
communicating with itself. This string of codes is the registration package.

The registration package is very suitable for the monitoring of the Internet of Things,
because the cloud software generally runs on the public network server of the Internet, and the
modules are scattered at various collection and monitoring points. How to make the cloud
software recognize the module is very important, and it is necessary to realize the
communication of the Internet of Things.

The serial server provides the following multiple registration package methods.

8 . 1 . 1 . SEND MAC ADDRESS ON CONNECTION

Send the MAC address on the connection: This method is not only supported for 4 models
(such as RS485 TO ETH (B)), but also for ordinary models. Its method is to send its mac address to
the cloud when the module is connected to the cloud. Since the MAC address is unique, it can
uniquely identify the device. This method is simple and does not require writing a registration
package for each device, so it is simple and effective. How to use it: Click "More Advanced
Settings" in the device settings dialog box, find "Send MAC address when TCP is establish" in the
upper middle, tick the front, and then return to the setting interface and click "Modify Settings" .

Figure 31 Sending MAC address on connection

8 . 1 . 2 . REALCOM AGREEMENT

The Realcom protocol is a mature protocol containing a registration package and a

heartbeat package. Users can use this protocol to realize the functions of the registration

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package and heartbeat package. The method to enable the Realcom protocol is: in the "Device
Settings" dialog box, select "Conversion Protocol" to "REAL_COM Protocol", and note that the
part of enabling the registration package needs to be blank and unchecked.

Figure 32 Enable realcom protocol

After the Realcom protocol is enabled, it will not be transparent transmission

communication. It has the following characteristics:

1. After the device establishes a TCP connection with the cloud, the device automatically
sends a hexadecimal registration packet FA 07 13 02 FA 02 MAC[5] MAC[4] MAC[3] MAC[2]
MAC[ 1] MAC[0 ] FA FF. Among them, MAC[5]~MAC[0] is the MAC address of the device.

2. When the device sends data to the network, it will automatically add the 3- byte header

prefix of FA 01 01.

3. Every keep-alive timing time, the device sends a 00 1-byte heartbeat packet to the
software. The REAL_COM protocol can be used as a device registration package because it
contains the MAC address in the registration package. However, due to its fixed format, only the
cloud software can design the REALCOM protocol to be compatible with this method.

8 . 1 . 3 . CUSTOM REGISTRATION PACKAGE

The custom registration package method is that the user can fill in an arbitrary registration

package format. The method is: in the device setting interface, the configuration is as follows:

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Figure 33 Set registration package

The difference with the REAL_COM protocol is that the registration package is enabled here,
and the registration package information such as 31 32 33 34 is filled in. Note that this is
hexadecimal, that is, the actual data sent is the string 1234. If you need to display a string, click
the "ASCII" option next to it.

When the device is connected to the cloud software, it can automatically send the
hexadecimal registration package of 31 32 33 34. This registration package method is more
flexible, allowing the device to adapt to the existing cloud registration package format; however,
there is no wildcard such as MAC in the registration package, and different registration packages
need to be configured separately for each device, which is more cumbersome. The above two
methods of sending MAC address and REALCOM have the same configuration for each device,
but the registration package is naturally different due to different MACs.

The longest registration packet length is 33 bytes. This method supports registration packets
and heartbeat packets in UDP mode.

8 . 1 . 4 . CONFIGURATION FILE

Support serial server to write a configuration file, so as to realize user- defined registration

package, and can use MAC address wildcard, which can solve the trouble of writing custom
registration package for each device, and there is no limit to the length of registration package.

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8 . 2 . HEARTBEAT PACKAGE

The heartbeat packet is mainly used to detect whether the communication link is
disconnected. The method of implementation is that the device sends a heartbeat packet data to
the server software at regular intervals. This data will be discarded after being received by the
server and will not be regarded as valid communication data.

The heartbeat packet has two main functions: First, it can let the host computer software
know that the device is active; secondly, if the device fails to send the heartbeat, the device at

the TCP client will automatically re-establish the TCP connection, so it is a recovery network

communication A means.

As shown in Figure 3 4 , the sending time of the heartbeat packet is set by the " Keep Alive

Time".

8 . 2 . 1 . IMPLIED HEARTBEAT

Even if you don't set any heartbeat packets, when the Micro Snow device is on the TCP
client side, the implicit heartbeat function will be enabled. Therefore, the implicit heartbeat
function means that the device sends data, but the server cannot actually receive the heartbeat
data. Therefore, it cannot play the first function of the heartbeat packet, that is, the server
detects whether the device is active or not; but because the device actually sends data, it can
play the second function of the heartbeat packet, that is, the device detects the TCP connection

Figure 34 Keep Alive Time

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8 . 2 . 2 . REALCOM PROTOCOL

As described in 8.1.2 Realcom protocol, REALCOM protocol can send a 1-byte data of 00

every keep-alive timing time. This data is the heartbeat packet of realcom protocol.

8 . 2 . 3 . CUSTOM HEARTBEAT PACKAGE

First, fill in the registration package according to the method of 8.1.3 customizing the
registration package. Then add the heartbeat packet as follows: Click the " More Advanced
Settings" button in the device settings, write the hexadecimal heartbeat packet in the second
line of the multi- destination IP and port, and change the option on the right to "Param. Dest".

Figure 35 Customized registration package

Note that the sum of the registration packet and the heartbeat packet should be less than
33 bytes. The first line is actually the registration package.

9 . REMOTE DEVICE MANAGEMENT

Whether the function is normal, once the disconnection is detected, the TCP connection can still

be automatically re- established.

The so- called remote device management refers to the ability to maintain and manage the
device through Vircom software, including restarting the device, modifying parameters, and
upgrading firmware. This function is suitable for users who use Vircom for device management.

For Vircom software, as long as the device can be found in the device list, it can be managed

remotely. The remote management of equipment is divided into the following situations:

1. Automatic search : The device and the computer are on the same switch. At this time, no
matter whether they are in the same network segment or not, the Vircom search method on the

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computer is: Vircom sends a broadcast query. After receiving the query, all devices will reply with
their own parameters. Vircom tools. This method searches all devices at once.

2. Manually add: There are two situations:

a) Large- scale routers divide the network : In some large- scale networks, broadcast packets
are divided by routers, so that the broadcast packets cannot reach the device end, but the ping
device IP is all connected. At this time, it generally needs to be added manually to solve the
problem. The method of adding manually is to click "Add manually" in the "Device Management"
dialog box to add the first and last IP to query the devices one by one.

b) The public network server queries the internal network equipment : the serial port server
is in the internal network and acts as a TCP server mode, and Vircom is on the public network IP
server. At this time, you need to do a 1092 UDP port mapping on the router of the network
where the device is located, and map it to the IP where the device is located, and then Vircom
manually adds the device. The IP is the public network IP of the device.

3. TCP client : When the device acts as a TCP client, it will initiate a TCP connection to port 419 6
of the destination IP (1 16 .1 5.2.3 ). After the connection is established, it will automatically send
its own parameter system to the UDP port (note that it is not the TCP port) of the destination
port ( here 41 96) at each keepalive timing, so that Vircom can be able to do so on this computer
(116.15.2.3) The device is found. If the destination port is not 4196, you need to modify the
Vircom's default parameter receiving port. The method is to modify the
menu/configuration/software configuration/default listening port, and then start Vircom. If a
TCP port conflict pops up, just ignore it and continue execution.

4 . Sending parameters at regular intervals: Even in a serial server in TCP server mode, you can
check the "Send parameters at regular intervals" function, and the parameters will be sent to the
destination port of the destination IP (here 116.15.2.3) every 5 minutes. Vircom that receives
parameters on this port of this server can manage these devices.

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1 0 . MQTT AND JSON

Figure 39 Timing sending parameters

In order to facilitate the identification of the device, if you need to perform

remote management, please give the device a name that is easy to remember.

For related usage, please refer to：

 MQTT and JSON Manual:

https://www.waveshare.com/wiki/RS485_TO_POE_ETH_(B)_MQTT_And_JSON_User_Manual

 Connect Alibaba Cloud And EMQX

https://www.waveshare.com/wiki/RS485_TO_ETH_(B)_Connect_Alibaba_Cloud_And_EMQX