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The Industry IoT Solution - Smart Meter2020/05/18

Era of Interconnection and communication between everyday objects: Internet of Things (IoT)


The explosive growth of Internet of Things (IoT) in recent years has developed a new network ecosystem. The core of the concept of IoT is to collect data through the sensor from various types of devices that are not supposed to communicate with each other, and then transmit the data to the data center through the network for analysis and integration before sharing the results of data resources to other IoT devices on the same network. As shown in Figure 1, the concept of IoT can be extended to everyday applications including consumer, commercial, industrial, and infrastructure space. IoT is almost everywhere. [1]


Figure 1. Concept of IoT


The architecture of the IoT system may vary depending on the application of each device, which can be basically classified into three tiers: Device, Edge Gateway and Cloud, as shown in Figure 2. The physical device (Device tier) provides the raw data to be interpreted to the Edge Gateway tier through a communication interface (wired or wireless) for data collection, aggregation or pre-processing prior to sending the data to the Cloud tier for analysis and management[1][2] .



Figure 2. IoT Architecture


Since the term “Internet of Things” was published by Peter T. Lewis in 1985, it has been widely applied in many ways. A research conducted by the “FinancesOnline”, a market research agency, showed the advantages of IoT terminal devices. As of 2015, there were 15.41 billion devices connected to IoT around the world and it is estimated that the number will get to 75.44 billion by 2025, which indicated that the IoT has been an inseparable part of our daily life.[3]


Industrial IoT Trends

The Industrial IoT is primarily used in manufacturing, followed by logistics and transportation. The relevant research organization estimates that the global industrial IoT market size is expected to reach USD 949.42 billion by 2025[4]. The industrial IoT applications are shown as in Table 1 below. Although manufacturing is the main area of industrial IoT, it has been used in energy & utility industries since the early stage.


Table 1 : Industry IoT Application[5][6]


Major Applications


◎ Predictive and remote maintenance.

◎ Industrial security systems

◎ Industrial heating, ventilation, and air conditioning

◎ Manufacturing equipment monitoring.


◎ Agriculture Automation

◎ Smart farming and livestock monitoring

Energy & Power

Smart metering and smart grid.

◎ Smart environment solutions.

Smart city applications.

◎ Energy consumption optimization


Healthcare Machinery

Oil & Gas

Ozone, gas and temperature monitoring in industrial environments


Asset tracking and smart logistics.

Asset performance management

Logistics & Transport

◎ Freight, goods and transportation monitoring.


In the energy & utility industries, the AMI (advanced metering infrastructure) system can measure and record energy usage such as electricity, water, gas and heat, and provide relevant data to the users and public facilities. Through the energy usage measured, collected and analyzed by the AMI system, the consumption data is periodically read from smart electrical, water, gas meters and sent to data center. The AMI is the architecture that enables two-way communication with smart meters between end users and utility companies.[7] Figure 3 below shows the data acquisition system via wired or wireless communication. The wired connection is mostly based on RS485 / RS232 / PLC, while LPWAN is adopted for IoT wireless connection in many countries.

The wired communication is the transmission of data over physical cables such as RS485, RS232 and PLC. The disadvantage of cable connection may require substantial cable setup fees and subsequent maintenance costs. However, compared with the wireless communication, it can achieve the data transfer success rate greater than 99%. As the LPWAN technology used for wireless communication, it is the main interface that enables long-range connection, low-speed transmission and low power consumption, and supports multiple access for M2M applications.



Figure 3. Data Acquire System


The smarter, the more complex

In addition to make our life more convenient, we have also started to notice that the smarter electronic products have the electromagnetic compatibility issue more complicated, including the smart meters. At present, many countries are promoting effective use of energy. By continuously optimizing the AMI system and meters, it can be more effective to manage the energy usage through the automated feedback on grid performance and any abnormal operation to reduce the costs of manual meter reads and maintenance. It also offers the end users an optional time varying pricing rate for choosing the lower rates during off-peak periods. These additional applications and communication modules must meet the EMC requirements of related meters to avoid any potentially interfering signals during communication process.


The smart meters are required to comply with ANSI C 12.1 or UL 2375 standard. These two standards do not conflict with each other. Some of the requirements of UL 2375 have been covered by ANSI C 12.1 standard, and the regulations to be followed are normally determined by the Public Utility Section [8], including Radio Frequency Conducted and Radiated Emission (Test No.27: ANSI C63.4), EFT (Electrical fast transient/burst - Test No. 25: IEC 61000-4-4), Electrostatic Discharge (Test No.28: IEC 61000-4-2). 


Smart meters are typically installed outside the house and exposed to a harsh outdoor environment. The interference under such environmental exposure affects the normal operation of smart meters. According to the EMC engineer – Kenneth Wyatt, there are three major causes for product failure: radiated emission, radiated susceptibility and electrostatic discharge (ESD). The design concept for ESD protection is to keep the space for TVS (transient voltage suppressor) on pad layout to improve the flexibility during verification. Therefore, at the early design stage, the considerations of appropriately placing the protection components on sensitive signals, high-frequency signals or power port to pass the requirements of lab tests and ensure the connection between communication module and IoT without interference have become an essential issue for the product engineer.




As being the leading supplier of electrostatic protection components, the AMC (Amazing Microelectronic Corp.) provides the ESD protection technology with low clamping voltage, low parasitic capacitance, high surge robustness and array package. The use of protection component with low clamping voltage can ensure the backend circuit to be controlled under the stable voltage and normal operation of signal potential when the abnormal energy enters the system. While protecting the high-frequency signals, the low parasitic capacitance of ESD protection component also complies with signal integrity requirements. Since the smart meters are usually installed outside the building, the high-robustness for surge protection can achieve higher level of reliability in design. The application of TVS array can save PCB space and reduce costs to a certain extent. It helps the smart meter manufacturers to minimize the costs while delivering a high-reliability product.


In addition, the switching-mode power supply (SMPS) used in smart meters is becoming mainstream on the market, which can improve smart meter efficiency. However, the SMPS circuit can easily cause an EMI problem. The EMI filter is the application for cutoff frequency from 35 MHz to 3.5 GHz on 3.3V power supply. The EMI filter in the SMPS is used to directly replace the voltage stabilizer at voltage end without the redesign of PCB.


As for the wire communication, AMC offers RS232/RS485/CAN transceivers to improve the protection of electrostatic discharge (IEC 61000-4-2), electrical fast transient/burst (IEC 61000-4-4) and surge (IEC 61000-4-5) on the external bus interface. Table 2 summarizes the solutions to connect IoT applications and AMI system, including the IoT communication module and smart meter.



Table2. Wireless Module and Smart Meter Application


Wireless Module

Smart Meter


Dedicated I/F




UART / USB Signal / SIM Card

Battery voltage protection

ESD, EFT or surge protect level

EMI Issue

Power EMI Filter



Band-Stop: 35MHz to 3.5GHz for 3.3V

Mainstream package

Wire Interface




◎3.3V ~ 5V I/O tolerance

◎Multi-package compatible




◎Support 3.3V & 5V Voltage

◎High Surge Type

◎Isolation Type




◎3.3V ~ 5V I/O tolerance

◎AEC-Q qualification

◎CANH/L high fault voltage protection

General purpose




GPIO & Power Rail

◎ Low working leakage current

◎ Variety package

N1: “XCVR” is an abbreviation; it stands for “transceiver”.



The IoT technology connects with people, M2M system and information resources. It is expected to be more diversified and applied to a wider range in the near future. The smarter electronic products have the electromagnetic compatibility issue more complicated. To ensure the most reliable EMC effect while having the optimal time to market is now a critical consideration. From the product design perspective, the time and costs of product certification will be greatly reduced if the product engineer can pre-evaluate the simulation and choose the protection components properly. The EMC design for IoT product is not only to meet the testing and certification requirements, but also to ensure its function reliability in the complex electromagnetic environment. [10] The AMC will keep playing a key role in the IoT field to provide reliable EMC solutions.



1. B.K. Tripathy, J. Anuradha.(2018) Internet of things (IoT):technologies, applications, challenges, and solutions. CRC Press Taylor & Francis Group.

2. Internet of things. WIKIPEDIA. [Online]. Available: 

3. Jenny Chang. 10 IoT Trends for 2020/2021: Latest Predictions According To Experts. [Online]. Available:

4. Industrial IoT Market Size Worth $949.42 Billion By 2025 | CAGR: 29.4%. GRAND VIEW RESEARCH. [Online]. Available:

5. Industrial IoT (IIoT) Market by Device & Technology (Sensor, RFID, Industrial Robotics, DCS, Condition Monitoring, Networking Technology), Connectivity (Wired, Wireless, Field Technology), Software (PLM, MES, SCADA), Vertical, Region - Global Forecast to 2025. MarketsandMarkets Research. [Online]. Available: 

6. Business guide to Industrial IoT (Industrial Internet of Things). i-SCOOP. [Online]. Available:

7. Smart meter. WIKIPEDIA. [Online]. Available:

8. Aaron F. Snyder. Modern Electricity Meter Safety, Accuracy and Performance Testing. EnerNex. [Online]. Available:

9. Kenneth Wyatt. The Top Five Reasons Products Fail EMI Testing. [Online]. Available:

10. MuRata China. [深度報導] 老問題,新挑戰:智能化趨勢下的EMC設計. [Online]. Available:


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