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Gateways & Firmware Requirement

1. Manual Description

1.1 Manual Purpose

This manual guides field technicians to quickly configure the Robustel edge computing gateway to forward collected data to higher-level systems (such as a BMS - Building Management System) using the Northbound BACnet/IP protocol.

1.2 Scope of Application

This manual is written for field implementation engineers. You do not need deep theoretical knowledge of the BACnet protocol. By following these step-by-step instructions, you can easily configure the gateway as a BACnet Server, map internal data tags to BACnet objects, and verify the data using third-party tools.

2. 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): The local field devices (such as a Modbus TCP Sensor) are connected to the gateway. The gateway actively collects data from these devices and stores the values internally as "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.

Figure 2-1 BACnet northbound network topology

3. Preparations

(Note: This document uses the LG3120 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:

3.1 Hardware Device Requirements

3.2 Environment and Network Requirements

• LAN Connectivity: The gateway, the debugging PC, and the Modbus TCP device 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 traffic on port 47808 (the standard BACnet/IP port).
• 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.

4. 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 Modbus TCP sensor simulator as an example to collect two tags: Temperature and Humidity.

4.1 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.

Figure 4-1 Open E2C Field from the gateway Web UI

4.2 Adding a Modbus TCP Device

(Note: This section assumes that you already have a Modbus Slave device physically connected to the gateway via an Ethernet cable.)

1. On the left menu of E2C Field, go to Data Collection > Wired Device.
2. Click the + Create button to add a new device.
3. Select Modbus TCP as the Driver.
4. Fill in the basic device parameters (refer to your sensor's manual):

5. Click Save.

4.3 Creating Data Tags (Temperature & Humidity)

Now we need to read the specific registers from the Modbus device. Let's assume the client's Modbus Slave manual states that the Temperature data is stored in Holding Register 40001 and Humidity is stored in Holding Register 40002.

1. Click on the newly created device (Sensor1) to enter its configuration page.
2. In the Tag List section, click Add to create two tags. Fill in the following parameters:

3. Click Save at the bottom, and then click Publish at the top right to start data collection.
4. Tip: You can check the Status to verify if the Temperature and Humidity tags are successfully reading values before proceeding to the BACnet configuration.

Figure 4-2 Create Modbus TCP data tags

Figure 4-3 Verify Modbus TCP data tag status

5. Northbound Configuration: BACnet IP Server

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

5.1 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:

Figure 5-1 Configure the BACnet IP server

5.2 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.

Figure 5-2 Map tags to BACnet objects

6. Verifying Configuration with Yabe

Now, let's test if our gateway is successfully working as a BACnet Server.

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 on it.

5. In the "Objects" window (bottom left), you will see the mapped objects:
6. AI:1 (mapped to Temperature)
7. AI:2 (mapped to Humidity)
6. 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.

Figure 6-1 Verify BACnet data with Yabe

7. Common Troubleshooting

8. Core Parameter Quick Reference

For quick on-site configuration, refer to these industry-standard concepts: