Robustel E2C Trinity LoRa Device to BACnet/IP Data Forwarding User Guide

Document Version: V1.0

Gateways & Firmware Requirement:

Manual Description

Manual Purpose

This manual is designed for field engineers who need to forward LoRaWAN sensor data to higher-level systems (such as a BMS — Building Management System) via the BACnet/IP protocol. By following the step-by-step instructions in this manual, you will complete the full configuration workflow from LoRa southbound data collection to northbound BACnet/IP data forwarding.

Scope of Application

You do not need deep theoretical knowledge of the BACnet or LoRaWAN protocols. By following the instructions in this manual, you can easily configure the gateway as a BACnet Server, map LoRa sensor data tags to BACnet objects, and verify the data using third-party tools.

Basic Concepts & Network Topology

Gateway Role: From Collector to Server

In a typical IIoT project, imagine the gateway as a translator between your local sensors and the Building Management System (BMS). The data flow consists of two main stages:

First Stage (Southbound): LoRaWAN sensors communicate with the gateway via wireless radio frequencies. The gateway acts as a LoRaWAN Network Server (LNS), receiving encrypted hexadecimal raw data from the sensors and decoding it into readable engineering values (e.g., Temperature: 26°C) using a Payload Codec script, then storing them as internal "Tags".

Second Stage (Northbound): The gateway operates as a BACnet IP Server on the network. It takes those internal Tags, converts them into standard BACnet objects, and exposes them so that a higher-level system, such as a BMS or a BACnet testing tool like Yabe Explorer, can continuously read the data.

Preparations

(Note: This document uses the LG3120e gateway and E2C Field software as an example. The configuration process for other supported gateway and software combinations is very similar.)

Before starting the configuration, please ensure the following preparations are met:

Hardware Device Requirements

Environment and Network Requirements

• LAN Connectivity: The gateway and the debugging PC must be connected to the same Local Area Network (LAN) (e.g., connected to the same switch or the gateway's LAN ports).
• IP Allocation: Ensure all devices have valid IP addresses in the same subnet (e.g., 192.168.0.x) and there are no IP conflicts.
• Port Accessibility: Ensure the PC's firewall allows UDP 47808 traffic (the standard BACnet/IP port).
• Wireless Coverage: LoRaWAN sensors must be placed within the gateway's wireless signal coverage range (actual distance varies by environment, typically up to several kilometers).
• BACnet Testing Tool: Download and install Yabe (Yet Another Bacnet Explorer) on your debugging PC. It is a free, industry-standard tool used to search and verify BACnet Server devices.

Prerequisite: Southbound Data Collection

Before forwarding data via BACnet, the gateway must first collect data from the field devices. In this guide, we will use a LoRaWAN temperature and humidity sensor as an example to collect two tags: Temperature and Humidity.

Logging into E2C Field

1. Connect your PC to the gateway's LAN port.
2. Open a web browser and enter the gateway's IP address (the default is usually 192.168.0.1).
3. Log in with your credentials and click Edge Computing in the gateway's Web GUI to enter the E2C Field software.
4. Workflow Overview To set up a new sensor, you need to complete the following steps:
   1. Check if the codec is pre-integrated (Step 1).
   2. If not pre-integrated, obtain and import the codec (Step 2).
   3. Create a Device Profile (Step 3).
   4. Add the LoRaWAN device and associate tags (Step 4).

Step 1: Check for Payload Codecs

The purpose of this step is to provide the gateway with a "translator" script to convert raw hexadecimal data sent by the sensor into readable data points (e.g., temperature, humidity, or battery level). You only need to do this once per sensor model. Please follow the path below based on your sensor's current status:

Please navigate to LNS Configuration > 【Payload Codecs】.

• If your sensor model is listed, the codec is already built into the system; please proceed directly to 【4.4 Step 3】.
• If your sensor is not listed, please proceed directly to 【4.3 Step 2】.

Step 2: Importing a Payload Codec

The system supports creating custom Codec files through either Add or Copy methods. These operations require the operator to have a technical background in Codec development. This step explains the method of importing a file, which has a lower barrier to entry and broader applicability, to complete the creation of a Payload Codec for the vast majority of standard use cases.

1. Obtain the Raw Codec File:
   1. Primary Source: Contact the sensor manufacturer directly to obtain the raw Codec file compatible with your specific model.
   2. Public Resources: If the manufacturer does not provide the file directly, you may search for it in these common community repositories:
      - Milesight: https://github.com/Milesight-IoT/SensorDecoders
      - Dragino: https://github.com/dragino/dragino-end-node-decoder
      - Other vendors: https://github.com/TheThingsNetwork/lorawan-devices
2. Convert Codec File Format: Use the conversion tool to process the raw Codec file into the TOML format supported by E2C Field.
   1. Place the e2c-trinity-codec-converter.exe tool and the extracted raw Codec folder into the same directory.
   2. Run the tool, then select the appropriate 【Vendor】 and 【Model】.
   3. Click 【Generate Codec TOML】 to complete the conversion.

3. Import to E2C Field:
   1. Navigate to 【LNS Configuration】 > 【Payload Codecs】 > 【Import Codec】 > 【Import from file】.
   2. Upload the generated TOML file.
   3. Mandatory Testing (Critical Step): This step verifies the decoding logic and determines which data points are available for your device.
      1. Go to the 【Uplink Test】 tab, input the sample hex payload provided in your sensor’s manual, and click 【Run Decode】.
      2. You must ensure the system successfully outputs the JSON result. Please note that the data points available to your device are entirely dependent on the output of this Run Decode process. For example, if your Codec file theoretically supports 50 data points, but the hex payload only successfully parses 2 points during the test, then the device will only possess those 2 data points after binding to this Profile.
      3. If your sensor supports downlink control, please perform the same test under the 【Downlink Test】 tab.
      4. Once the test is successful, you must click 【Publish】 to save the codec; otherwise, it will not take effect.

Step 3: Create a Device Profile

Purpose of this step: To define the shared network settings for a specific model of sensor. Instead of typing the frequency and join settings for multiple identical sensors, you create one Profile and apply it to all of them.

1. Go to LNS Configuration > Device Profiles > Create New.
2. Configure the parameters based on your sensor's manual according to the table below:

3. Click [Publish] to finish the profile.

Step 4: Add a Device and Associate Tags

Purpose of this step: To register the actual, physical sensor to the gateway using its unique IDs, and select which data points (Tags) you want to collect.

1. Go to Data Collection > LoRaWAN Device > Add Device.
2. Configure the physical device identity:

3. Click [Next] to enter Tag Verification.
4. The system will automatically list all available data points (Tags) this sensor can provide (e.g., temperature, humidity, battery). Check the boxes for the tags you need.
5. Click [Confirm], then click the [Publish LoRa] button at the top right of the screen to apply changes.

Verifying Southbound Data Collection

Once added, power on or reboot your physical sensor to force it to join the gateway.

1. Check Connection Status: Go to Data Collection > LoRaWAN Device. Look at the Status column. A green icon means the sensor has successfully joined the gateway.
2. View Data: Click the [View Tags] icon (eye symbol) next to your device.
3. Observe the Latest Value and Update Time columns. If you see real numbers (e.g., 25.5 for temperature) updating periodically, your sensor is successfully online and sending data.

Tip: You can check the Status to verify if the Temperature and Humidity tags are successfully reading values before proceeding to the BACnet configuration.

Northbound Configuration: BACnet IP Server

This is the core step where we expose our internal tags to the BACnet network.

Creating the BACnet IP Server

1. Go to Data Forwarding.
2. Click the [+ Create] button at the top, select BACnet IP Server, and click Save.
3. You will enter the BACnet IP Server Configuration page. Enable BACnet IP Server Configuration and configure the Basic Settings:

Mapping Tags to BACnet Objects (Crucial Step)

The Yabe / BMS does not understand the internal tag names like "Temperature". It only understands standard BACnet Objects like "Analog Input 1 (AI:1)". You must translate them using the BACnet IP Mapping Table.

1. Scroll down to the BACnet IP Mapping Table section, click the [Add] button.
2. In the new row, configure the mapping for your tags. Fill in the following parameters and Save:

3. Click [Add] again and repeat the process to map the second tag (Humidity) using the values shown in the table above.
4. Click [Submit] at the bottom to save the configuration.
5. Very Important: Click the [Publish] button at the top right of the page. The configuration will only take effect on the edge gateway after publishing.

Tip: This section uses AI (Analog Input) as an example to demonstrate the most basic mapping workflow. If you need to map other types of BACnet objects (such as BI, BO, MSI, etc.), or need to understand detailed rules for data conversion and write-back, please refer to Chapter 8 "BACnet Mapping Rules in Detail".

Verifying Configuration with Yabe

Search and Discover the Gateway

1. Open the Yabe software on your PC.
2. Click the green [+] (Add device) button under the Devices window.
3. Select your local PC network interface and ensure the port is 47808 (Hexadecimal: BAC0, as Yabe uses hex for port numbers). Click Save.
4. In the Devices tree on the left, you should see a node named BACnet IP Server 0 (where 0 is your Local Device ID). Click to expand it.

Read Object Values

1. In the Objects window (bottom left), you will see the mapped objects:
   • AI:1 (mapped to Temperature)
   • AI:2 (mapped to Humidity)
2. Click on AI:1. Look at the Properties window on the right. Find the Present_Value property. If it shows the correct real-time temperature (e.g., 28), your BACnet data forwarding is successful.

Verify Write-back (Optional)

If you have configured writable tags on the southbound side and mapped them to writable BACnet object types (such as AO, BO, MSO), you can verify the write-back function as follows:

1. In the Yabe Objects window, find a writable object (e.g., AO:1) and right-click on it.
2. Select Write Properties, change the Present_Value to the target value, and click confirm to send.
3. Observe the result:
   • For wired devices (such as Modbus): write-back usually takes effect immediately.
   • For LoRaWAN sensors: The write-back command will be internally queued by the gateway and sent when the sensor wakes up for its next communication. Therefore, it will not take effect immediately. Please be patient (the waiting time depends on the sensor's configured reporting interval). This is determined by LoRaWAN's power-saving mechanism.
4. Note: [Conversion Mode] also takes effect during write-back (downlink). For example, if set to Round, a floating-point value sent by the BMS will be converted to an integer according to this rule before being written back to the southbound device.

Common Troubleshooting

Core Parameter and Mapping Rules Reference

Quick Parameter Reference

BACnet Mapping Rules in Detail

Object Type to Southbound Data Type Mapping

Data Conversion Rules (Uplink Forwarding / Downlink Write-back)

Conversion Mode

The mapping page provides a [Conversion Mode] field, which is empty by default (dropdown single-select). Options are as follows:

• Round: 2.3 → 2, 2.5 → 3
• Ceil: 2.3 → 3
• Floor: 2.3 → 2

If left blank, the system defaults to Round. This setting applies to both Data Forwarding (uplink) and Write-back (downlink).

+1 Offset for MSI / MSO / MSV

When mapping to MSI, MSO, or MSV object types, an [Enable +1 Offset] checkbox will appear, checked by default.

• When checked: BACnet Present_Value = Original tag value + 1. For example, if the original tag value is 0, BACnet displays 1.
• When unchecked: BACnet Present_Value = Original tag value, no offset. For example, if the original tag value is 0, BACnet displays 0.

Recommendation: In the BACnet standard, Present_Value for MSI/MSO/MSV starts from 1. If your original tag values start from 0, it is recommended to keep [Enable +1 Offset] checked to ensure compliance with the BACnet standard.