Internship report pizitech co , ltd topic researching and understanding about iot to collect data in the solar power system

3/1/2022 – 27/3/2022 Week 1 -Research and learn about Modbus-Learn about RS485, Modbus RTU, Modbus TCP/IP protocol-Take courses about Modbus onUdemy.com Week 2 Week 3 -Do research on the

-o0o -INTERNSHIP REPORT

Pizitech Co., Ltd Topic: Researching and understanding about IoT to collect

data in the solar power system

Instructor: Mai Bá Lộc Student: Trần Quốc Huy Student ID: 1851072

HO CHI MINH CITY, MARCH 2022

First of all, I would like to thank the members of Pizitech Co., Ltd and Mr Le Duc Toan for creating favorable conditions and guiding me wholeheartedly so that I could study and complete this internship.

I would like to thank Mr Toan for guiding, introducing documents, answering questions and helping me during the whole internship process Thanks to that, I accumulated more knowledge, experience and practical working environment Since then, I have gained more experience and applicable knowledges on my own.

I would like to thank Professor Mai Ba Loc for enthusiastically guiding and answering all questions during the internship at the company From there, I was able to complete the internship in the most complete way.

In the process of interning and making reports, due to lack of practical experience, errors cannot be avoided I would like to thank the members of Pizitech Co and Professor Mai Ba Loc who have guided and supported me so that I can complete the report in the most complete way.

Ho Chi Minh City, March 5, 2022

Student

Trần Quốc Huy

1 ABOUT PIZITECH CO., LTD 1

1.1 Introduction 1

1.2 Duties and functions of the company 2

1.3 Organizational structure and personnel of Pizitech company 2

2 INTERNSHIP CONTENT 3

2.1 Task assignment: 3

2.2 Timetable and schedule of the internship progress 3

3 ASSIGNMENTS CONTENT 4

3.1 Research about Modbus 4

3.2 RS485 interface 7

3.3 Modbus RTU 8

3.4 Modbus TCP/IP 10

3.5 Research on PV panels system in solar energy and apply Modbus for monitoring and management 11

3.6 Connecting to the solar system and designing the monitoring interface 14

4 INTERNSHIP SUMMARY 19

4.1 Internship results 19

4.2 Experiences learned during the internship 19

5 RERFERENCES 20

FIGURE LIST

Figure 1.1 1

Figure 3.1 5

Figure 3.2 9

Figure 3.3 9

Figure 3.4 10

Figure 3.5 11

Figure 3.6 12

Figure 3.7 12

Figure 3.8 15

Figure 3.9 15

Figure 3.10 16

Figure 3.11 16

Figure 3.12 17

TABLE LISTTable 2.1 3 Table 3.1 14

1 ABOUT PIZITECH CO., LTD

1.1 Introduction

- Pizitech Co., Ltd was established in 2017, with the strength of youngpeople working with Microsoft technology The company focuses onbringing the best product experience to customers The company isdeveloping products in the transportation industry such as parkingsolutions, CRM, cargo management solutions

- Besides, the company also has a consulting department to deploytechnology solutions to help customers and partners of the companyhave the best IT infrastructure The company will provide the rightsolution for your company/organization One of the main tasks of thecompany is product development, which aims to solve life's problems.Products that combine software, cloud computing, IoT hardware to getthe most complete solution IT infrastructure is one of the core things ofthe company

Figure 1 1

1.2 Duties and functions of the company

- With a right IT strategy, your business or organization can survive in thedigital age and avoid potential risks

 Areas of operation of the company

- Website design: Website will create many advantages in business Thecompany will help create an amazing virtual representation of you in thedigital world

- Mobile application development: Mobile application is the key ofbusiness So the company will bring the best experience to the palm ofyour hand

- Business management solutions: The company provides comprehensivemanagement solutions such as ERP, CRM, HRM for yourorganization to improve business efficiency and reduce potential risks

- IT Strategy: With the right IT strategy, your business or organizationcan survive in the digital age and avoid risks The company will always

be by your side to provide the right and timely IT strategy

- Development and application of IoT infrastructure: In parallel with thedevelopment of IT strategy, where everything is connected and linkedtogether, it is impossible not to have a modern and stable IoT system

1.3 Organizational structure and personnel of Pizitech company

- Pizitech offers experienced and dedicated resources combined with amodern organization and strong management structure With the goal ofcombining employees, customers and partners to deliver the best resultsand service quality in this highly competitive market segment Theorganizational structure of Pizitech is divided into 2 divisions,performing separate, cooperative and mutually supportive jobs:Executive Management Board, Solutions Department and ProductDepartment:

 Solution Department: Carrying out the tasks of infrastructure surveyconsulting, strategic consulting and project implementation andplanning.

 Production Department: Provide hardware and software needed forthe project

2.1 Task assignment:

- Task 1: Read documents and learn about Modbus in industry, whichincludes RS485 protocol, Modbus RTU, Modbus TCP/IP

- Task 2: Research and analyze the company's solar power system and how

to apply Modbus in monitoring and controlling the system

- Task 3: Connect to the system via Modbus TCP/IP to collect andmonitor, design a simple GUI interface to connect and displayinformation

2.2 Timetable and schedule of the internship progress

Internship schedule at Pizitech Co.

3/1/2022 – 27/3/2022

Week 1 -Research and learn about Modbus-Learn about RS485, Modbus RTU,

Modbus TCP/IP protocol-Take courses about Modbus onUdemy.com

Week 2

Week 3 -Do research on the solar grid power

system-How to apply Modbus in monitoringand managing the system

Week 4Week 5 -Use ModbusTool.exe to connect to

Modbus system in the grid-Design a simple GUI interface tomonitor the power parameters of thegrid

- There are 3 main types of Modbus protocol being used widely in theindustry:

 Modbus ASCII

 Modbus TCP

 Modbus RTU

 Working principle of Modbus

- MODBUS is a "master - slave" system, "master" is connected to one ormore "slaves" The “master” is usually a PLC, PC, DCS, or RTU TheMODBUS RTU “slaves” are typically field devices, all connected to thenetwork in a multi-drop configuration When a MODBUS RTU masterwants information from a device, the master sends a required datamessage, a debug summary, to the device address Every other devices

on the network will receive this message, but only the specified devicewill respond

- Devices on the Modbus network operate in a reactive mode followingthe commands sent down from the Master

 Transmitted data structure in Modbus protocol

- Including 4 main parts:

 Device Address: This address field helps the master determinewhich slave it is working with Slaves will be assigned addressesfrom 1-247 and must ensure that no Slaves have the same address

This field is in the first position in a Modbus message and is 8 bits

in size

 Function Code: This field follows the Device Address field and is 8bits in size, which specifies the action the Master requires the Slave

to perform, such as reading/writing one or more data in the device

 Data: Is used to store data exchanged between slave and master TheData field of the Query message contains additional informationthat the Slave must use to take action according to the FunctionCode For Response messages, the Data field will contain the datarequested by the Master

 Error Check: This field is used to check for frame errors, it occupies16-bits corresponding to 2 bytes Modbus RTU uses CyclicalRedundancy Check method

Hình 3.1

 Security fallbacks of Modbus

- Lack of security: All Modbus messages are transmitted in clear textover the media If somehow an attacker can install a transceiver into theModbus network, the attacker can read the entire message content andthen perform malicious actions

- Lack of data integrity: Unable to check data integrity in Modbus TCP/IPapplication protocol (because Error Check CRC is removed) Anattacker can make requests to the Master or Slave, from which it is

possible to inject invalid messages into the network causing networkfailures

- Lack of authentication: No authentication at any level of the Modbusprotocol All Modbus devices do not need to authenticate access to thenetwork An attacker can inject another device into an existing Modbusnetwork without authentication

- Simple Frame: Modbus TCP/IP uses TCP/IP and Ethernet to carryModbus message structure data between devices that are compatiblewith the network standard (TCP/IP) Modbus messages have a size limit

of 256 bytes If an attacker enters error messages that exceed theallowed size, it can cause a buffer overflow

- The control system integrates many different communication protocolsconnected to Modbus to transmit and receive data to serve the function

of control and monitoring of production equipment An attacker can useanother protocol to access the data and signals of the device usingModbus to perform destructive actions

- In systems using Modbus, control stations with similar functions oftenuse the same design An attacker can use information available from onecontrol station to attack another control station that has a repeaterfunction

- Control devices, network devices, etc can usually be accessed, becausethe username and password are set to the manufacturer's default Anattacker can use the credentials to infiltrate the Modbus network andperform destructive actions

- The number of connections Modbus allows is more than actually used

In practice using the user to default to the manufacturer's settingsallowing the maximum number of connected devices, an attacker couldbreak in, use unused connection addresses, and perform acts of sabotage

- Industrial systems are not regularly updated or updates are slow or donot synchronize software Attackers can take advantage ofvulnerabilities of old versions, infiltrate the system to perform

destructive actions This is true for all protocols in the industrialenvironment in general, not just Modbus.

 Application of Modbus

- Modbus is also the most common communication protocol in buildingindustrial automation systems and the most common means available forconnecting automated electronic devices, collectively known as IoT(Internet of Things)

- Modbus was the first widely accepted fieldbus standard In a short time,hundreds of vendors have implemented the Modbus communicationsystem in their equipment, and Modbus has become the de factostandard for industrial communication networks

3.2 RS485 interface

 What is RS485?

- RS485 [2], also known by its full name RS485 communication standard

or RS485 cable, this is a communication method that connects tocomputers and other devices RS485 is not just a single interface but it is

a communication complex capable of creating simple networks of manydevices

- RS485 communication standard can connect up to 32 devices on asingle wire pair and a ground wire system at a distance of up to 1200m

 Construction of RS485

- RS485 cable is constructed very simply, only from wires twistedtogether in pairs However, this very structure creates a seriousdrawback, when interference occurs in one pair of wires, immediatelythe other pair of wires will also suffer This leads to the operatingvoltage between the 2 wires will not have too much difference, thereceiver of RS485 can still receive the signal because the receiver haseliminated all interference

 Working principle of RS485

- The principle of operation of RS485 is quite simple, data will betransmitted through 2 wires twisted together, this wire is called twistedcable When the wire is twisted, it will give RS485 high anti-interference ability and better long-distance signal transmission.

- RS485 is divided into 2 types of configuration, currently the mostcommonly used is 2-wire configuration and 4-wire configuration

 Receivers with input resistance up to 12kΩ RS485 can still connect

up to 32 devices In addition, with other inputs, RS485 can connect

up to 256 devices

 When RS485 is connecting devices at quite a distance, users canovercome it by installing more repeaters to increase the number ofconnected devices, making the signal more stable, and avoiding lineinterference

 RS485 has 2 signal transmission lines installed, so the signal will betransmitted faster over longer and wider distances

- In a device communication network using the Modbus RTU protocol,sensors or actuators often act as slaves; Devices such as computers,PLCs, microcontrollers, HMI devices, etc can be Master devices, butsometimes they can also act as slaves.

Figure 3.2

- The transmission frame of the Modbus RTU protocol builds on theUART serial communication protocol UART protocol is also a serialcommunication protocol, used in microcontrollers, it defines thestructure of a packet to send a byte how to send bits And the content ofModbus messages is built up of multiple packets

Figure 3.3

- In the OSI structure, Modbus RTU is an application layer protocol, so it

needs the underlying physical layer to connect with other devices.Standard physical links RS232 and RS485 are used for this protocol

Figure 3.4 3.4 Modbus TCP/IP

- Modbus-TCP/IP [5] is a Modbus protocol used on Ethernet lines, usingTCP/IP model for communication

- Modbus-TCP is an open industrial Ethernet network recognized by theModbus-IDA User Organization

- Like other modbus types, Modbus TCP/IP also uses Master-Slave modelfor communication However, deployed over Ethernet, using the TCPprotocol suite over IP

- Modbus TCP changes the traditional Master-Slave definition BecauseEthernet allows peer-to-peer communication In the TCP network, theSlaves can actively transmit information about the central managementdevice - the Master Use IP addresses on the Masters for centralizedmanagement from the software

- Modbus TCP/IP is used on modern TCP/IP networks, there are 2 types

- Modbus TCP/IP can be combined with modbus RTU Called HybridModbus As shown below

-Figure 3.5

- Modbus RTU uses RS485, RS232 Modbus TCP is used over Ethernet

So if you want to combine these two types of modbus, you need to find

a device that supports these two ports This will greatly benefit youwhen expanding the production scale, the number of devices

3.5 Research on PV panels system in solar energy and apply Modbus for monitoring and management

 Solar power system: