MQTT (Message Queuing Telemetry Transport) is a communication architecture developed by IBM for the Internet of Things (IoT). It is useful for mobile applications because of its small size, low power usage, minimized data packets, and efficient distribution of information to one or many receivers, especially in unstable networks. MQTT is implemented based on the publish/subscribe architecture. In its network, there is a server (Broker) responsible for the intermediary layer of information, and other devices can send information to the Broker by publishing a topic, or get information from the Broker by subscribing to a topic.
BRK Series is Sever of MQTT, can connectwith large amount of ICP DAS modules with MQTT protocol: for example, the DL-300 series of data Logger sensors which canmeasure CO, CO2, Temperature, Humidity and Dew Point information. The communication mechanism that supports MQTT publishes the collected on-site environment parameters to the BRK Series, and can simply monitor the on-site environment from a long distance by subscribing to the BRK Series using a mobile device or SCADA software that supports MQTT Client. The Ethernet I/O modules of the MQ-7200M series can automatically publish the collected digital I/O values to the BRK Series through MQTT. The MQTT Client only needs to subscribe and publish to the BRK Series to monitor or change remotely DO status of the Ethernet I/O modules.
System Architecture
Features:
Provide Bridge and Cluster functions, which allows excellent scalability
The Bridge and Cluster functions can expand the limits of service and data sources for MQTT Broker applications:• Bridge function
Allows BRK series to forward/subscribe the messages to other BRK series or third-party MQTT Brokers. By forwarding messages, it can direct themessage to other BRK series service side. By subscribing to the remote brokers, it can increase the data sources.
• Cluster function
Allows BRK series in the same group to share data to others with lower resources. When the number of connections and messages exceeds thelimit of a BRK, using the cluster function can increase the number of connections to meet the needs.
► Support High Availability architecture
When there are more than two BRK devices in the same site, they can be set as backup between each other. When the BRK device that is providingservices fails or goes offline, other BRK device can detect and take over in a short time to ensure that the service will not be interrupted for a long
time.
► Support Load Balancing Function, which can effectively configure tasks and optimize MQTT communication
The BRK load balancing function can be used in conjunction with the MQTT bridging or clustering function. A BRK device in this group provides a
single fixed IP and communication port to connect other BRK clients in the group, which can be effectively allocated to the BRK devices in the group
for MQTT communication services. This function simplifies user configuration and maximizes the overall system service capacity: when a single or a
small number of devices in the group fail, the connection can be redistributed to other BRK devices to continue to provide communication services.
► Support Redundancy System
Based on the High Availability architecture and Load Balancing function. This redundancy is hardware backup. In the entire MQTT Broker group, if
one of the BRKs fails or disconnects, the other BRKs with normal functions will take over to provide MQTT services, and users do not need to perform
other related settings.
Application
Bridge Architecture Application
Many corporations have large factories, ex: manufacturing, and some areas (ex: confidential data areas or clean rooms) require access control, which causes inconvenience in entering and exiting that takes longer when need troubleshoot. The corporations often take remote control systems to solve the problem. However, the remote control will expose the devices to the external network environment. As long as any device in the system has a data security vulnerability, the entire system may be attacked or even paralyzed.
ICP DAS provides BRK-2000 Series MQTT Bridge Architecture. Through the MQTT Bridge mechanism, only the Topics and permissions that are authorized to be transmitted will send to the Remote Broker in the Bridge Architecture. And the built-in MQTT connection authentication methods such as Account/Password, Client ID, Certificates, etc., to increase the security of the communication to protect data. When doing the remote control, the operations are only to the Remote Broker. The equipment network in the factory can separate from the external network. If the external network communication is abnormal, the internal factory system can still operate without external influence.
Redundancy Architecture Application
With the development of the Internet of Things, more companies widely use Machine-to-Machine communication to track on-site producing processes, machine operating conditions, report errors, and issue service alerts in real-time. Under the needs, how to protect data from natural disasters and man disasters that damage the system or data has always been the main topic.
ICP DAS provides the BRK Redundancy Architecture for a solution that uses two BRK-2000 Series, one BRK-2000 (Main Broker) provides the MQTT services, and the other is used as a standby backup (Backup Broker) monitor the Main Broker at any time. Once the Main Broker is abnormal (such as shutdown without warning), the standby Backup Broker will take over in time. The MQTT service will not be interrupted, the system manager will have more time to deal with the problem, and the entire system will continue work.
Cluster Architecture Application
The manufacturing industry often deploys sensors to collect the machine status of the production process, parameters, etc. to improve production efficiency, control quality, and reduce the production line shut down due to equipment failure. The sensors send these data to the control center to perform calculations and visualization so that the on-site person can instantly get the status of the production process. However, during the data collection process, the control center may not get the field devices data due to the failure of the network traffic.
To solve this problem, ICP DAS provides the BRK-2000 Series Cluster Architecture that uses two and more BRK-2000 to form a High Availability Cluster. The BRK devices in the Cluster share to do the MQTT services. Since the BRK devices in the Cluster can complete the same tasks, if one BRK fails, other BRK devices can continue to work, thus ensuring the nonstop of MQTT services. BRK-2000 has a built-in Load Balancer function, which allows connection services to be equally distributed in the Cluster, making full use of the processing capabilities of each Broker in the Cluster and improving the processing efficiency of tasks.
Plastic Injection Molding Machine Monitoring Applications
Due to labor costs increasing and manpower shortages in the manufacturing industry, how to digitize information is an important issue, companies have trouble integrating IT and OT staff because they have different perceptions, and eventually have to abandon the project. The difficulties, in this case, can be divided into the following items:
1. Hard to record Sensor value
2. Machine messages scattered
3. No Data Graphing
ICP DAS uses the U-7526M to convert analog signals into RESTful API / MQTT data to achieve the goal of "information digitization". Makes it more flexible for database and graphic software and makes it easier to control and record.
Advantages of ICP DAS:
1. Digitalization for recording
2. Centralized message
3. Data graphing
Architecture of ICP DAS:
IIoT MQTT Communication Server
| Model | OS | CPU | SDRAM | Flash | Non-Volatile Memory | microSD Card | Ethernet Port | USB Port |
|---|---|---|---|---|---|---|---|---|
| BRK-2841M | Linux Kernel 4.1.15 | Quad-core ARM CPU, 1.6 GHz/Core |
DDR3 1 GB |
8 GB | FRAM 64 KB MRAM 128 KB |
4 GB (Max. 32 GB microSDHC or 2 TB microSDXC) |
2 | 2 |