1) Introduction

Welcome to user manual of YuDash LYNX IoT gateway. Configuration steps and information is covered in this manual.

In summary following are main aspects in configuration of LYNX IoT Gateway:

1) How to connect LYNX to network?

2) How to connect and configure LYNX to field instruments over industrial protocols.

3) How to configuration of LYNX with 3rd party IoT platform. By default, LYNX is pre-configured with YuDash YuFourIA IoT platform.

4) Storing and Retrieving LYNX setting on local drive.


1) As the LYNX product and user interface is continuously evolving, some of UI interfaces may be slightly different in your gateway.

2) While the UI would show all features, it may not be applicable for given model of IoT gateway.

2) Terminal Connections and Wiring Information

3) LYNX Configuration Page

YuDash LYNX is and easy to configure IoT gateway. It can be configured through a laptop, tablet or mobile phone through WiFi. There is no need to install any software or LAN wiring.

3.1) Starting LYNX Configuration Page

Following are 3 simple steps to initiate LYNX configuration..

Step 1: On LYNX bootup, press the Config button (top left terminal) to start the configuration server. It is marked as SW or CN on the LYNX terminals.

Step 2: Once the button is pressed, the device will enter in AP (Access Point) mode, meaning a WiFi network will be broadcasted. The wifi SSID name and password are displayed on the LYNX screen. Connect the laptop to the given wifi.

Step 2(a): For example:

  1. wifi SSID: yudash318

  2. Wifi password: 12345678

  3. LYNX IP address:

Step 3: This is how LYNX configuration page looks like on laptop.

Step 3(a): his is how LYNX configuration page looks like on a mobile phone.

LYNX will keep the configuration server running for upto 5 minutes on inactivity. All LYNX configuration will be done through this page as covered in subsequent sections.

Troubleshooting Guide to start LYNX Configuration Page

1) In some cases, WiFi may be shown as "Open network". In this case, no need to enter WiFi password.

2) At times, the WiFi setting on laptop may be showing "Connecting.." instead of "Connected to WiFi" after LYNX WiFi is selected. No need worry. Please open the Configuration URL ( on laptop. It should simply open.

3) In case of further trouble, please "Forget" any previously stored WiFi names linked to LYNX.

3.2) LYNX Configuration Sections

Following are main sections in YuDash LYNX Configuration page:

1) LYNX Device Information: This is read-only section with LYNX model, hardware and firmware information.

2) Network Setting: This section is used to configure network connectivity of LYNX. Depending on model, LYNX can connect to internet through (a) 4G/LTE (SIM card) (b) WiFi or (c) Ethernet LAN. It can also work in offline mode (when it is used for local storage or display only).

3) LYNX Settings: This is main section in which all features of LYNX are configured. It includes (a) data send frequency, (b) Feature enable/disable (given industrial protocol) and (c) Custom cloud selection. Specific configuration of given feature in done in subsequent sections.

3.3) LYNX Device Information

LYNX Device Information read-only section with LYNX model with following information:

  1. Part No: The device part number.

  2. Serial No: Unique Serial number of the device.

  3. Hardware Ver: Hardware PCB version.

  4. Firmware Ver: LYNX firmware version.

  5. Default Device Settings: By default, each YuDash LYNX gateway is pre-configured with "YuDash Cloud". Effectively, given LYNX IoT gateway is mapped to a unique "device" on YuDash IoT platform.

  6. Get Mac Address Button: This button fetches the MAC address of the LYNX ioT gateway. This MAC address is used for both WiFi and Ethernet. This may be typically required for

4) Network Settings

LYNX Network Settings section deals with connection of LYNX with the network. It is typically internet or local LAN in some cases. Depending on model, LYNX supports following option to connect to network:

  1. WiFi: LYNX connects to a WiFi network (router) to access the internet/local LAN. All models of LYNX supports connection to internet through WiFi.

  2. Ethernet: LYNX connects to internet through Ethernet (RJ45 jack).

    • By default, it assumes DHCP connection (in which IP address is assigned by router). In this case, there is no further settings needed.

    • LYNX also supports static IP address configuration under advanced Ethernet settings.

  3. 4G/LTE (Sim card): LYNX connects to internet through 4G/LTE SIM card.

    • Support of all 4G networks, independent of carriers. LYNX has been tested with all carriers in India.

    • Option to provide carrier APN. Though, this is not critical.

    • Support of external antenna for in-panel applications.

  4. None (Offline): LYNX is not being connected to any network and used as display unit. This mode is also used to debugging purpose.

4.1) Read and Write Network Settings

  1. Click on "Read Network Settings" button. The network settings will be populated in configuration page from LYNX. It may take 1-2 seconds for this process.

2. Various network Settings are populated in the configuration page from LYNX. Apply required changes in given section.

3. After all changes are completed, click on Write Network Settings button. This will update the network settings in the LYNX. A popup is displayed. After clicking on Write Network Settings, wait for 2-3 seconds for update.

4. Click on Reboot LYNX button to reboot the LYNX. Alternately, LYNX can be power cycled. LYNX will use updated Network Settings after reboot. During initial runs, it is better to cross check that settings have been updated in LYNX after the reboot.

4.2) Selection of Network Settings in LYNX

Network Selection radio button is used to select a given type of network. Details of each network type is covered in following sections.

Selection of Network Settings in YuDash LYNX

4.3) Updating WiFi Settings in YuDash LYNX

  1. To Change the WiFi settings, click on show password checkbox. Update the WiFi SSID name and password in given text boxes.

2. In above settings, the SSID#1 has been changed from yudashdemo to my_test_1 and password has been updated. Similarly, WIFI SSID#2 has been changed to mytest2.

LYNX WiFi Features and Specifications

  • LYNX supports DHCP Wifi connection only.

  • LYNX support 2.4GHz WiFi only. 5GHz WiFi networks are not supported.

  • LYNX supports DHCP Wifi connection only (IP address issued by WiFi router).

    • For on-premise solutions, WiFi with local LAN access can be used (without need of internet).

    • LYNX has in-built WiFi antenna. There is no provision of external WiFi antenna.

  • There is provision to provide two WiFi networks. By default, LYNX attempts connection to first WiFi (WiFi SSID#1 and WiFi Password). In case, it is not connected, it will attempt to connect to (WiFi SSID#2). It is not mandatory to fill both WiFi settings.

YuDash LYNX WiFi Trouble Shooting Guide

Please consider following in case you are facing WiFi connection issues:

  1. Check special characters and space in WiFi SSID and password entry boxes.

  2. Create a simple SSID name and password using mobile phone and first connect to that WiFi

4.3) Updating 4G/SIM LTE Settings in LYNX

When 4G/LTE sim card is selected, LYNX use 4G connection for connecting to internet. In general, there are no settings required.

  • There is option to provide APN (Access Point Name) which can be selected based on carrier. In our observation, it is not mandatory to update this.

  • The option 4G TimeOut (sec) is the time LYNX will attempt to connect to the SIM network. Depending on network strength, it takes upto ~20 seconds for LYNX modem to connect to network. This setting can be tweaked in case of connectivity issues.

Inserting SIM card into YuDash LYNX

5) LYNX Settings

This is main LYNX setting section in which all device configurations of LYNX is done. Primary LYNX settings include:

a) What data to read and process. It includes what instruments to read and their protocols settings (Modbus/RS485, Analog, Modbus/TCP).

b) Where to send data (Cloud/LAN server). It may be default YuDash IoT platform or customer's cloud server.

c) Enabling, disabling and configuring specific features of LYNX (depending on LYNX model).

Following are generic steps to read and update LYNX settings.

  1. Click on Read LYNX Config button. This will fetch LYNX settings from the LYNX.

2. After this step, complete LYNX settings are populated. In above example, the loop delay of 60 seconds is set. Modbus/RS485 is enabled and default YuDash cloud is used.

3. In this example, Loop Delay has been changed to 120 seconds under General Settings.

4. After making changes, click on Update and Preview button. This steps check validity of all settings before writing to LYNX.

5. Click on Write LYNX Config button. This will write updated settings in LYNX. A popup is displayed that settings have been sent to LYNX.

6. After all changes are completed, reboot LYNX by clicking Reboot LYNX button under Network Settings.

5.1) General Settings

This section has following components:

1) Loop Delay (Sec): This the cycle time (in seconds) of main loop of LYNX.

Following is main operation cycle of LYNX:

a) Read the data from given set of instruments.

b) Process and send the data to given cloud.

c) Wait (Sleep) for given cycle to complete. During this wait time, LYNX performs background task as specific in the settings.

Loop Delay defines the frequency of data processing of LYNX. If Loop Delay is specified as 60 seconds (1 minute), LYNX will send process data to IoT platform every 1 minute.

Notes on Loop Delay:

  • The loop delay has to be set by customer based on given application and required data frequency on cloud. Please note that there is cost (bandwidth, storage) involved with each data point. Typically, all IoT platform (including YuDash) have data plans depending on volume (number and frequency) of data points.

  • The cycle-time of LYNX is subject to time taken in reading instruments and network connectivity. Typically, instrument reads (on Modbus or analog) are instantaneous, but the read cycle may be prolonged in case of invalid registers or settings, causing timeouts and retrials.

  • In case, the loop delay is set to be too low, which is less than processing cycle time, there will not be any wait in LYNX.

  • For typical cloud applications loop delay of 2-5 minutes (120 to 600) will be suitable to capture real-world parameters.

2) Device Name: A device name (string) provided by customer. It is displayed on OLED during running. This is only for information, traceability purpose. This is not used in any data processing.

Updating Loop Delay in LYNX Settings.

5.2) Feature Settings

This section enables/disables a given feature (protocols) of LYNX using Checkbox. Each protocol is configured in subsequent sections. Please note following:

  • It is ok to configure a given feature and still keep it disabled in this section.

  • Even though all features may be displayed in configuration page, availability of given feature depends on LYNX model.

Following are features which can be enabled/disabled:

1) Modbus/RS485

2) Analog Inputs

3) Digital I/Os

4) Digital Sensors.

5.3) Cloud/Network Server Settings

This section defines the server (cloud or local LAN) on which data has to be sent. By default, LYNX will send data to YuDash cloud (when "Use YuDash cloud" is checked).

Besides YuDash cloud, YuDash LYNX can send data on HTTP, MQTT and FTP servers. The cloud servers are configured in Custom Cloud Server Settings in which all credentials are specified.

  • YuDash support variety of JSON payload settings.

  • It supports majority of popular IoT platforms which can be used in a plug and play manner.

  • Similar to field instrument settings, it is ok to populate settings of various network protocols in LYNX.

5.4) Save/Load LYNX Settings

LYNX provides and easy backup and restore or LYNX configuration settings. After initial settings, one can "download" the settings in a text (json) file on laptop/mobile. Let's call the file lynx.json. This lynx.json can be later restored (re-loaded) in LYNX to overwrite all LYNX settings.

The network settings remain unaffected in this backup and restore. Network Settings have to updated manually only.

For some of advances features, the lynx.json can be edited directly in JSON format.

Saving (Downloading) LYNX Settings on local Laptop/PC as JSON text file.

Loading LYNX Settings from JSON in local laptop/PC.

6) Modbus/RS485 Settings

Modbus/RS485 is a popular serial protocol to read various sensors. YuDash LYNX is being used to read variety of instruments, sensors and PLCs for various application. LYNX provides easy to configure approach for reading field Modbus instruments. Following are key information required for successful read of instrument through Modbus:

  1. Baudrate

  2. Data Bits, Parity and Stop Bit

  3. Slave ID of instrument

  4. Modbus register information to read:

a) Modbus register numbers and types)

b) Modbus register data types (Size: integer/float/real. Byte swapping information: LSB/MSB etc).

  1. Modbus register address.

6.1) Modbus Register Mapping in YuDash LYNX.

Following four inputs have to be provided for processing of each Modbus register in YuDash LYNX:

1) Variable Name: YuDash LYNX reads a given Modbus register and store it in a variable. This is the user defined string, which will be sent to IoT platform/server along with process values. For sending to YuDash cloud, the variable names should be all small letters without any blank spaces. Sample variable name: volt1 temperature_celcius amp_01 amp_02 machine_status_flag

2) Register No: The register types/function codes of Modbus are defined by register numbers itself. User has to specify complete #Register No. in Modbus register section.

Following is available range of registers:

01) COIL STATUS: 0 to 9999

02) INPUT STATUS: 10000 to 19999

04) INPUT REGISTERS: 30000 to 39999

03) HOLDING REGISTER: 40000 to 49999

Important Note: LYNX use base-0 register addressing (starting with 40000). OEM instrument manual use both base-0 or base-1 registers, so that they have to checked accordingly. The MODSCAN use base 1 register addressing (starting with 40001). So, after MODSCAN regsiters are identified, you have to enter register as one less than the MODSCAN register.

3) Type: The data type of Modbus registers are specified in data Type code in MODUS register settings. Following are register type codes:

Code Description Number of Registers read




4 REAL 64 BIT (LSB first) 4

41 REAL 64 BIT (MSB first) 4

11 Bit pattern Extraction 1

4) Factor: LYNX provides option to post process register value after reading of inputs. The register value is divided by the value provided in Factor. By default, Factor of 1 used . Typically, Factor of 10 or 100 may be used in cases when Modbus registers are integer representation in multiple. For example, there are cases that voltage of 234.6 is represented as integer of 2346 in modbus register . In these cases, factor of 10 can be used. With this factor, LYNX will read 2346 integer value, divide by 10 and send 234.6 on the cloud platform. This helps in receiving values on cloud which maps to values seen on display. In many cases, 100X value is used in integer form.

In most of industrial applications, MODSCAN (or similar) software is used to validate the Modbus settings. In case of any troubleshooting, we strongly suggest to validate the communication through MODSCAN. Our tutorial explains the mapping in reference of MODSCAN to LYNX settings.

6.2) Modbus/RS485 interfacing example

To explain Modbus/RS485 mapping in LYNX, we will interface it with a single phase energy meter to read it's voltage and frequency.

1. Selec make EM2M is used to interfance with MODSCAN software followed by YuDash LYNX

2. Energy Meter MODUBUS settings checked in MODSCAN sofrware.

3. Voltage and Frequency values test-read in MODSCAN software and co-related with datasheet values.

4. Corresponding settings updated in YuDash LYNX Modbus/RS485 section.

5. Video for Updating MODBUS/RS485 Settings in YuDash LYNX

7) Analog Input Settings

Few variants of LYNX support direct analog read inputs. The variants with suffix A (for example: LYNX42A) supports analog input read.

LYNX supports 4 channels of 0-20mA read. The terminals A1 to A4 terminals are available for 4 channels of analog.

In most of industrial applications, 4-20mA values is mapped to given process values. LYNX has advances data scaling features to handle process values of different applications.

While user can perform scaling within Analog Inputs, but we recommend using generic Data Scaling section of LYNX for analog data interpolation.

Analog Inputs Settings has 4 buttons for 4 channels, which can be enabled/disabled and configured independently.

Analog Inputs feature has to be enabled (check box) in LYNX Feature Settings to process analog channels.

7.1) Configuration of Analog Inputs Channel

1) A given analog channel (A1 to A4) has to be enabled by clicking checkbox.

2) Output values range [minOutVal, maxOutVal]: These are the output values range (minimum and maximum) of the analog module. This can be used for basic linear scaling of inputs. If set to [0, 100], the analog output will be 0 to 100 for given input mA range (0-20).

3) Input Current range [minmA, maxmA]: This is range of input milli Amperes to be read. For most of applications, this should be 0 and 20. For instrument calibration, the maxmA may be set lower than 20 (say 19.8) to map to real-world process values.

4) varName: The variable name in which output value will be stored

5) varName2: For analog inputs, this is optional additional variable name in which analog output will be stored. Keep it blank unless necessary.

6) varFactor: The output value will be multiplied by the varFactor. We will keep it 1.

Analog Input Settings for a given channel

8) Data Scale Settings

This a data-processing layer for scaling of input data. This can be applied to any variables (read by Modbus, analog or any sensors). Following are basic steps to use this feature:

1) Click on Open DataScale Settings button. It will open table a dummy values.

2) Click on Read DataScale Settings button. It will update the table with actual DataScaling settings for a give variables (if present).

3) Update the variable names and scaling. It is mandatory to have Enable Scaling Flag ticked to get a given scaling function enabled.

4) Click on UpdateDataScale Settings button to update the data scaling features.

For a given variable, following Data Scale function is applied:

a) The variable is scaled using values provided in the Input Range (Minimum and Maximum) to the Out Range (Minimum and Maximum).

b) After above step, the output values are clipped to be within range of Minimum Cutoff Limit and Maximum Cutoff Limit values.

It is not mandatory that variable should be within Input Range value. Input and Output Range values are used to create the slope and offset (y=mx+c) to derive at output value. Finally, the output values can be clipped using Cutoff Limit values.

Dummy Variables populated when Open DataScale Setting is clicked.

Data Scale variables populated after ReadDataScale Settings is click.

Scaling functions applied to 4 variables (as defined in analog section). Enable Scaling Flag has been ticked to have scaling function enabled.

Explanation of DataScale function in representative example:

1) analog1_celcius: Input values 0 to 20 (mA) will be scaled to -5 to 55. This example uses an analog temperature. The output values are clipped to -5 to 55. Just in case analog value becomes >20 or <0 due to calibration error, the output will always be in range -5 to 55.

2) analog2_aox: This example represents an air analyzer sensor, in which 4-20mA range represents value of 0 to 600. In case the sensor is OFF (or not working), the input values of 0mA (any value less than 4.0) will first be calculated as a -ve value. But it will be clipped to be in range of 0 to 600 using Cutoff Limits.

3) analog3_freq: This represents a AC drive which gives frequency output in 0-20mA range. But, it was identified during calibration that actual mA output of AC drive was only 19.8 at full 50Hz frequency. So, we scale 0-19.8 input to 0-50Hz and apply cutoffs.

4) analog4_humidity: A sample humidity scaling function. In this case, the error cases are identified using out-of-range limits (-1 to 101) to represent error scenarios.

9) Advance Feature Settings

This section covers following key features of LYNX IoT gateway. These are available depending on part number:

  • RTC (Real Time clock)

  • Network failure handler (local backup and restore)

  • Remote Configuration of deployed Device

10) Custom Cloud Settings

By default, YuDash LYNX is configured as a "device" on YuDash cloud with unique serial number. Based on subscription plan, YuDash cloud is for complete IoT application, or it can be used for remote device management (YuReCon).

Besides default cloud, LYNX support seamless connectivity to various IoT platforms (on cloud or on-premise) through MQTT and HTTP (REST APIs). LYNX has inbuilt payload formats in JSON and text format to support various servers. This section covers MQTT and HTTP interfacing. Please refer to this link for detailed API and sample integrations is

. This is covered in separate

usappThis section covers following key features of LYNX IoT gateway. These are available depending on part number:

11) Ethernet Settings

LYNX has ethernet (RJ45) as optional hardware feature depending on part number. The ethernet port can be used for following purposes:

1) Network connectivity

  • Ethernet port is used to connect to cloud (or on-premise server). The en to cloud server (or on-premise server). This is enabled by selecting Ethernet in Network Settings.

  • Ethernet supports dynamic IP (DHCP) and static IP option. By default, dynamic IP is assumed in which IP address is assigned by local LAN router. In this case, there is no further configuration in this section. This is most common use-case for most of applications.

2) TCP/IP (or UDP) Communication with field instrument.

  • Ether is used to communicate with with PLC/HMI or other machines (using Modbus TCP/IP, SNMP, OPC-UA and other industrial protocols).

  • For this application, Ethernet/LAN has to be enabled under LYNX Feature settings. Subsequently, applicable TCP/IP based protocol has to enabled and configured

  • It is feasible to use Ethernet port for both (1) Network connectivity and (2) Field instrument communication, assuming that instrument is connected to main network.

Enabling Ethernet/LAN in LYNX Feature Settings

11.1) Ethernet Settings for Static/Dynamic IP

Click on "Read Ethernet Settings" to load present settings. After clicking on "Update Ethernet Settings", the settings will updated.

In case, there are not settings present, a popup "Ethernet Setting Not present" will be alerted. This reflects that default dynamic IP address of TCP/IP being used.

For Static IP settings, select the "Static" radio button and fill the IP address details. Please fill either (a) ALL four entries or (B) ONLY IP address (applicable for peer-to-peer connection).

For dynamic IP, select In "Automatic/DHCP" radio button. With this selection, the cutom IP address details are not used by LYNX. So, it is ok to leave them filled.

12) Modbus TCP/IP Settings

YuDash LYNX supports Modbus TCP/IP to read various PLC/HMIs through ethernet. In principle, following are pre-requesites for using Modbus TCP/IP

  1. Valid Ethernet settings of YuDash LYNX for communication over TCP/IP

  2. LYNX is Modbus Client, who request the data. The given PLC is MODBUS server, who will provide the data. LYNX can read multiple Modbus TCP/IP servers.

  3. Following details of a given Modbus Server (PLC) are required for communication:

  • IP address of PLC. For example:

  • IP Port on which Modbus server is running. For example: 502 (standard port). Or 8888 (any port being used by PLC)

  • Modbus Server ID as per protocol. For example: 1 (The Server ID of MODBUS is similar to slave ID of Modbus RS-485)

  • Modbus Registers and Data Types The mapping of registers and selection procedure is similar to Modbus RS-485

There are different network topology possible for Modbus TCP/IP. This is explained in a video in which LYNX is communicating with HMI on Modbus TCP/IP.

13) SNMP Settings

YuDash LYNX supports SNMP (Simple Network Management Protocol) over Ethernet. It is used to read UPS and other IT/networking assets.

  • Basic Configuration (SNMP server settings) is available in the configuration UI.

  • The configuration of SNMP parameters is done through JSON format in LYNX. Due to complexity and arcane nature of SNMP, we do not offer UI based configuration.

  • YuDash team works with OEMs to map their SNMP assets to LYNX.

  • SNMP protocols works on concept of MIB files which has mapping of asset parameters. We support this mapping through JSON interface. Subsequenctly