UTEK UT-6801S-GW User manual

Your Reliable Partner in Industrial IoT
UTEK TECHNOLOGY
Model: UT-6801S-GW
(Product Name：Modbus Gateway)
User manual
UTEK TECHNOLOGY (SHENZHEN) CO., LTD.
Add: Room 1001, Building 7, Skyworth Innovation Valley, No. 8, Tangtou No.1 Road,
Shiyan Street, Shiyan Old Street, Bao 'an District, Shenzhen
Tel：[phone]
Fax：[phone]
Http：www.uotek.com

Your Reliable Partner in Industrial IoT
UTEK TECHNOLOGY
Conventions
This manual adopts the following conventions.
GUI Convention
Description
Description
Supplement and explain the description of the operation
content.
Attention
Remind of things to pay attention to during the operation.
Improper operation may cause data loss or device damage.

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Foreword
Target readers
This manual is intended for installers and system administrators who are responsible for installing,
configuring, or maintaining networks. This manual assumes that you understand the transmission and
management protocols used by all networks.
This manual also assumes that you are familiar with the professional terminology, theoretical
principles, practical skills, and specific professional knowledge related to networking devices, protocols,
and interfaces. At the same time, you must have working experience with graphical user interfaces,
Simple Network Management Protocol, and web browsers.
1. Product Overview
1.1 Product Introduction
UT-6801S-GW is a Modbus gateway. It is a Modbus protocol converter between asynchronous serial
port RS232/422/485 and Ethernet. It is an independent intelligent device with CPU, embedded OS, and
complete TCP/IP protocol stack. It can immediately connect RS232/422/485 serial port Modbus RTU
devices to the network.
Product features: supporting dynamic IP (DHCP) and static IP, supporting Modbus RTU to Modbus
TCP conversion function, and having storage-type Modbus gateway characteristics. Data can be
transmitted via the Internet. Communication conversion between Modbus RTU Slave, Modbus RTU Master,
Modbus TCP Master, and Modbus TCP Slave. Internally integrated with ARP, DHCP, TCP, IP, HTTP, ICMP,
MODBUS, and other protocols. It can be used as long as you know how to use a computer.
1.2 Product Features
Hardware features
Has a Reset button to restore factory default settings.
Has one 10/100M industrial-grade adaptive Ethernet port;
The serial port provides 5 signals, including RXD, TXD, RTS, CTS, GND; with three serial port interfaces
of RS232/485/422.
The network port and power supply have independent indicator lights to conveniently indicate the
working status;
Wide power input range (12~57.6VDC), suitable for different on-site power supply methods.
Software features
Supports ARP, DHCP, TCP, IP, HTTP, ICMP, MODBUS, and other protocols.
Supports a wide range of baud rates from 300-921600bps (standard baud rate), suitable for
applications between different devices.
Supports setting two operation modes on the serial port page: Modbus RTU Master and Modbus RTU
Slave.
Supports upgrading web firmware to facilitate special applications in different scenarios.
Modbus proxy mode, storage type, faster response, and better stability.
2. Hardware Description
2.1 Power Interface Terminal Definition
The UT-6801S-GW front panel provides DC and 3PIN 5.08 power terminal for power connection, and
the power input range is 12-57.6VDC. It is recommended to use a power adapter with a DC jack
specification of inner diameter 2.5mm and outer diameter 5.5mm.

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2.2 Ethernet RJ45 Interface Definition
The UT-6801S-GW supports one Ethernet port and one RS-232/485/422 serial port.
10Base-T/100Base-TX Ethernet interface
The 10/100BaseT(X) Ethernet interface is located on the front panel of the device, with an RJ45
interface type. The pin distribution of the RJ45 port is defined as shown in the figure. Connection uses
unshielded twisted pair (UTP) or shielded twisted pair (STP), and the connection distance does not exceed
100m. The 100Mbps connection uses a 5th category line with 100Ω, while the 10Mbps connection uses a
3rd, 4th, or 5th category line with 100Ω.
The RJ45 port supports automatic MDI/MDI-X operation, which can be connected to a PC or server
using a straight-through cable and connected to other switches or hubs. In a straight-through cable (MDI),
pins 1, 2, 3, and 6 correspond to the connection. For the MDI-X port of a switch or hub, a crossover cable is
used: 1→3, 2→6, 3→1, 6→2. The pin definitions of the 10Base-T/100Base-TX in the MDI/MDI-X application
are shown in the table below.
Note: "TX±" is for transmitting data + and -, "RX±" is for receiving data + and -, "-" means unused.
MDI (Medium Dependent Interface)：
Terminal block
Power Interface
1
Positive pole V+
2
Connect to ground (PGND)
3
Negative pole V-
Pin No.
MDI singal
MDI-X singal
1
TX+
RX+
2
TX-
RX-
3
RX+
TX+
6
RX-
TX-
4、
5、7、8
—
—
1 8

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MDI-X (crossover cable):
MDI/MDI-X auto-adaptive function makes it easy for users to use the 10/100BaseT(X) Ethernet
interface of UT-6801S-GW without considering the type of Ethernet cable. It can be directly connected to
devices through a crossover or straight-through cable.
2.4 Serial Port Definition
The UT-6801S-GW provides a 7-pin industrial wiring terminal with a spacing of 5.08mm. Its pin
definitions are shown in the table below:
2.5 Indicator Lights
The UT-6801S-GW provides LED indicator lights to monitor the working status and simplify
troubleshooting. The detailed status of each indicator light is shown in the table below:
Name
Color
Function
Status
PWR
Red
Power indicator light
Steady on
Terminal block
RS-485
RS422
RS232
1
A(DATA+)
A（TxD+）
-
2
B(DATA-)
B（TxD-）
-
3
-
A（RxD+）
-
4
-
B（RxD-）
-
5
-
-
TX
6
-
-
RX
7
-
-
GND

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LINK
Green
Network indicator light
Steady on
Serial Port Data
Light
Green
Serial port data transmission
and reception indicator light
Flashing when there is data, off
when there is no data
RUN
Green
Operating status light
Alternating flash at 0.5s on and off
2.6 Device Installation
Before installation, confirm the device's operating environment, such as power supply voltage,
installation space, and installation method. Please carefully check the following installation requirements:
Check if the necessary cables and connectors for installation are available.
Check if the cables are in place according to reasonable configuration requirements.
The product does not provide installation components. Users need to prepare components for the
selected installation type: screws, nuts, and tools, etc., to ensure reliable installation.
Power supply requirements: 12-57.6VAC.
Environmental requirements: operating temperature is -40~85℃, operating humidity is 5%~95%
(non-condensing).
Installation method: DIN rail installation (default), wall-mounted installation (optional).
2.7 Cable Laying
The cable laying must meet the following conditions:
Before laying the cable, verify that the specifications, models, and quantities of all cables meet the
requirements.
Before laying the cable, check whether the cable is damaged, whether there is a factory record, and
quality assurance certificates to prove its quality.
The required cable specifications, quantity, direction, and laying position all meet the construction
requirements, and the laying length should be determined according to the actual position.
There should be no broken wires or intermediate joints in the laid cable.
The cables in the aisle should be straight, neat, evenly curved, smooth, and straight.
In the slot channel, the cable should be straight, not exceeding the slot channel, to avoid blocking
other incoming and outgoing wire holes. The cable should be tied and fixed at the outlet of the slot channel
or at the bend of the cable.
User cables and power cords are laid separately. When cables, power cords, and ground wires are laid
in the same groove, they cannot overlap or mix. When the cable is too long, the cable's regular ground
should be placed in the middle of the cable tray and should not be pressed on other cables.
Both ends of the cable should have corresponding markings, and the marking content should be
concise and clear for maintenance.
3. Web Management
Before configuring the UT-6801S-GW Modbus gateway device, ensure that the necessary software
has been installed on your computer and the network has been configured reasonably.
3.1 Network Settings
The default IP address of the UT-6801S-GW Modbus gateway device is 192.168.1.125, and the subnet
mask is 255.255.255.0. When accessing the UT-6801S-GW Modbus gateway device through the web, the IP

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of the gateway device and the computer must be on the same local network. You can modify the
computer's IP address or modify the IP address of the Modbus gateway device to ensure that their IPs are
in the same local network. The specific steps can refer to the steps of Method 1 or Method 2.
Method 1: Modify the IP address of the computer.
Click Start->Control Panel->Network Connection->Local Connection->Properties->Internet Protocol
(TCP/IP). Set the IP address of the PC to 192.168.1.X (X is any value from 2 to 253 except 254).
After clicking OK, the IP address is successfully modified.
The specific Windows system operation page is shown in Figure 3.1:
3.2 Function Menu
The main menu includes Serial Port Settings, Ethernet Settings, System Management, Modbus
Settings, and User Settings. The content of each item will be introduced and configured in this chapter.
Menu Items
Page Functions
Serial Port
Settings
Basic parameters setting for serial port
Ethernet
Settings
Basic parameters setting for Ethernet
System
Management
Supports factory reset and firmware upgrade functions

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Modbus
Settings
Basic parameters setting for Modbus
User Settings
Support password modification for users
Save Settings
Perform save operation
3.3 Login to Web Interface
Before accessing the Modbus gateway device through the IE browser, ensure that the PC and the
device being accessed are on the same local network.
Operation method:
1. Right-click on IE, select Properties, and clear IE temporary files and history.
2. Open IE and enter the IP address of the UT-6801S-GW Modbus gateway device in the address bar.
Press Enter to enter the username and password confirmation page as shown in Figure 3.1.
3. Enter the username and password, press Enter to enter the UT-6801S-GW Modbus gateway device
interface as shown in Figure 3.2.
The web configuration page is divided into three parts: menu bar, operating area, and
English/Chinese switch. Clicking on a menu item in the menu bar can enter the corresponding interface,
and the configuration area displays device status information and can be configured.

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If the username or password is entered incorrectly, the interface will prompt "Incorrect user name or
password" as shown in Figure 3.3, and it must be re-entered.
3.3.1 Serial Port Settings
Enter the UT-6801S-GW Modbus gateway device's web interface, the web interface is shown in
Figure 3.4.
Select Serial Port
Default is single serial port
Interface Type
RS-485/422/232, default RS485

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Baud Rate
300-921600 (standard baud rate), default 9600
Data Bits
5, 6, 7, 8; default 8
Stop Bits
1, 1.5, 2; default 1
Parity Bit
None, odd, even; default none
Timeout
Device reply timeout time, range 0-5000ms, if exceeded device will not reply and
gateway reports error code; default 100
Operating Mode
ModbusRTU Master (default), ModbusRTU Slave
3.3.2 Ethernet Settings
Enter the UT-6801S-GW Modbus gateway device's web interface, and the web interface is shown in
Figure.
IP Address
A 32-bit address assigned to a device connected to the Internet. An IP address consists of
two fields: a network number field (net-id) and a host number field (host-id). The IP
address format is X.X.X.X, default display: 192.168.1.125.
Subnet Mask
The mask is a 32-bit number corresponding to an IP address, some of which are 1s and
others are 0s. The mask can divide the IP address into two parts: the subnet address and
the host address. The subnet address corresponds to the part in the IP address and mask
where the bit is 1. The format of the mask is X.X.X.X, default display: 255.255.255.0.
Gateway
The default gateway in the host is usually referred to as the default route. The default
route is the route selected by the router when the destination address in the IP packet
cannot be found in other routes. All packets whose destinations are not in the router's
routing table will use the default route. The format of the gateway is X.X.X.X, default
display: 192.168.1.1.
DNS
DNS stands for Domain Name Server, which is used to resolve domain names that are
easy for us to remember into IP addresses that the Internet can recognize. If our device
needs to access a hostname, we need to use this server to resolve it to an IP address.
The format of the DNS address is X.X.X.X, default display: 0.0.0.0.
Ethernet
Rate
Set the interface rate to Auto Negotiation, 10M Half Duplex, 10M Full Duplex, 100M Half
Duplex, 100M Full Duplex, Enable, disable. DHCP is also available.
DHCP
A 32-bit address assigned to a device connected to the Internet. An IP address consists of
two fields: a network number field (net-id) and a host number field (host-id). The IP
address format is X.X.X.X, default display: 192.168.1.125.
3.3.3 System Management

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Enter the UT-6801S-GW Modbus gateway device's web interface, and the web interface is shown in
Figure.
Device Model
Device Name Description
Firmware Version
Software Version Number
Hardware Version
Hardware Version Number
Factory Reset
Factory reset settings, parameter initialization, default IP: 192.168.1.125.
Firmware
Upgrade
Upgrade firmware program, restart required after upgrade.
3.3.4 Modbus Settings
Enter the UT-6801S-GW Modbus gateway device's web interface, and the web interface is shown in
Figure.
Listening Port
Default is 502, which is the device port connected to the TCP side, with a range of
1-65535.
Polling Interval
The polling interval time for each Modbus RTU instruction, with a setting range of
0-10000ms and a default of 200.
Address
Conversion
Settings
Query the address conversion table, with a maximum input of 15 address
conversion entries.
Index
Maximum of 15 address entries.

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Type
Two types are available: Serial Port (Master) and TCP Address (Slave). The two
modes cannot be applied to the same serial port at the same time.
Slave Address
Translation
Virtual <=> Real, the converted real address becomes the virtual address.
Add
After setting the parameters, click "Add" and save and restart the settings in the
Save Settings section.
Slave address is
ID number setting, with a range of 1-247
Slave conversion
address
increment value
The increment value range is from -254 to 254 and can be negative, adding to the
ID range of addresses.
Target
Serial1 or IP address + port, corresponding to the serial port or service IP + port of
the address conversion entry.
3.3.4.1 Mode 1
The UT-6801S-GW supports multi-master and multi-slave, and can convert between Modbus TCP and
Modbus RTU protocols. They can be accessed by up to 5 TCP master/client devices or connected to 5 TCP
slave/server devices. The GW601S gateway can easily integrate Modbus TCP and RTU networks, providing a
simpler and customizable network integration solution.
For Modbus deployments, the UT-6801S-GW gateway can effectively connect a large number of
Modbus nodes to the same network. It can manage up to 16 serial port slave nodes (devices), with ID
ranges from 1 to 247 (Modbus standard defines Modbus IDs from 1 to 247). Each RS-232/422/485 serial
port can configure different operation commands and baud rates for each Modbus RTU, allowing two types
of Modbus networks to be integrated into a Modbus TCP network through a Modbus gateway.
3.3.4.2 Mode 2
Serial port master server connects multiple Ethernet slave servers. If using a Modbus serial master
device with only one serial interface and need to access Modbus TCP slave devices, you can configure the

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work type as Modbus slave in the gateway's web page, and then configure up to five Modbus TCP slave
connection parameters on the page.
3.3.4.3 Mode 3
TCP master devices can establish connections with different Modbus slave devices. Each serial port of
the gateway can be configured as a specific environment, and after configuring the ID mapping settings,
the TCP master network communication protocol can access Modbus serial devices through the gateway.
Each serial port can manage up to 16 serial port slave nodes (devices), for example, managing up to
16 slave devices connected via RS-485, with ID ranges from 1 to 247 (Modbus standard defines Modbus IDs
from 1 to 247).
3.3.5 User Settings
Enter the UT-6801S-GW Modbus gateway device's web interface, and the web interface is shown in
Figure.

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Logout
Exit the current interface and return to the login interface.
Current
Password
Enter the current original password.
New
Password
Change to a new login password.
Confirm
Password
Enter the same password as the new password for confirmation.
Set
Click "Set" and restart to take effect.
3.3.6 Saving Settings
Enter the UT-6801S-GW Modbus gateway device's web interface, and the web interface is shown in
Figure.
After making changes to the gateway settings, click on "Restart". There will be a prompt box that
pops up, as shown in the figure below:
4. Example
a) Modbus RTU Master
1. This mode represents the serial port as the master station, and in the serial port configuration page,
check whether the parameters correspond to the devices under the serial port.

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2. Open the Modbus settings page, configure the address conversion rules, and map the virtual address
from the real address. The default factory configuration is as follows:
Open two debugging tools (Modbus Poll and Slave) respectively on the upper computer.
3. The Modbus slave tool configuration page is as follows, enter the COM number of the serial port device
and the corresponding configured serial port parameters.

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Continue to configure specific connection parameters. On this page, configure the slave ID to
configure the master station address (real address), such as ID=1, which means the master station ID is
0x01. Several commonly used configuration items are as follows:
Function can be configured with the corresponding function code, which should correspond to the
information configured by the slave station, such as displaying F=03, which is the 03 function code (holding
register).
Address configures the starting register address.
Quantity configures the length of read/write registers, and the length setting needs to correspond to
the slave station.
After the connection between the master and slave stations is established, you can monitor the message
interaction on this page.

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4. Open the Modbus poll tool, click Connection, and configure the gateway's IP and monitoring port on this
page, set the connection timeout time, click OK, and the PC actively connects to the device network as a
client.
Continue to configure specific connection parameters. On this page, configure the slave ID to
configure the slave station address (virtual address), such as ID=1, which means the slave station ID is 0x01.
Several commonly used configuration items are as follows:
Function can be configured with the corresponding function code, which should correspond to the
information configured by the slave station, such as displaying F=03, which is the 03 function code (holding
register).
Address configures the starting register address.
Quantity configures the length of read/write registers, and the length setting needs to correspond to
the master station.
Multiple pairs of new entries can be created by clicking the New button on the left, and the
corresponding ID numbers can be set separately, as shown in the figure below.

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b) Modbus RTU Slave
1. This mode represents the serial port as the slave station, and in the serial port configuration page,
check whether the parameters correspond to the devices under the serial port.
Open the Modbus settings page, configure the address conversion rules, and map the virtual address
from the real address. Only one working mode can be enabled for the same serial port.
On this page, set the type to TCP Address, set the address range and increment, and set the target to
the IP and port of the PC.

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Up to 15 slave address translation entries can be set.
Modbus TCP can support up to 5 connections and can connect to different five TCP servers.
Open two debugging tools (Modbus Poll and Slave) respectively on the upper computer.
2. The Modbus slave tool configuration page is as follows, select Modbus TCP connection mode.

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1) Enter the IP address of the PC and the port number in IP Address. The gateway acts as a client and
actively connects to the port opened by the PC.
2) Configure the slave address and function code on the Setup->Slave Definition page, and check the
starting address and length of bytes for read/write.
3) Open the Modbus poll tool, select Serial Port as the connection method, and check whether the
COM number and serial port connection parameters correspond to the serial port parameters configured
on the gateway configuration page.
4) Configure the slave address and function code on the Setup->Read/Write Definition page, and
check the starting address and length of bytes for read/write.
5) After successful connection, it is shown as follows:
When the two tools are connected to the RTU side and the TCP side respectively, if Err is displayed as
0, it indicates that everything is normal. If Err increases, it indicates that the slave station has no response
or other problems such as response timeout.