International Journal of Modern Trends in Engineering and Research e-issn No.: , Date: April, 2016

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1 International Journal of Modern Trends in Engineering and Research e-issn No.: , Date: April, 2016 Development of Embedded PLC with the application of Irrigation System Purva N. Authankar 1, Manoj A.Mechkul 2 1 Department of E&TC, PG Student, SNJB s college, Chandwad, Maharashtra, India, pauthankar@yahoo.com 2 Department of E&TC, Assistant Professor, SNJB s college, Chandwad, Maharashtra, India, mechkulmanoj@gmail.com Abstract - A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical operations, such as control of machinery on factory assembly lines, light fixtures or amusement rides. PLCs is inherently the relegation of human control function to technical equipment for increasing productivity, reducing cost, increasing quality, increasing safety in working condition. Unlike general purpose computers, the PLC is mapped for various inputs and output arrangements, resistance to vibration and impact, exempt to electrical noise and extended temperature ranges. Programs to control machine operation are often stored in nonvolatile memory or battery backed- up. A PLC is a prototype of a hard real time system since output results must be produced in response to input conditions within a finite period of time, otherwise unexpected operation will result. The development of the embedded PLC is designed with the combination of the LabVIEW software and the ARM Microcontroller. The flexibility of the proposed PLC makes it comparatively easy and less costly. The ARM microcontroller is preferred to develop embedded PLC since it is widely used across many embedded designs due to its low price and low power consumption. Extension to this, the LabVIEW Embedded Module for graphical programming to ARM microcontroller is used with the application of irrigation system for water sprinkling in agriculture field. Keywords- Programmable Logic controller; ARM microcontroller; Embedded PLC; LabVIEW software; Irrigation system. I. INTRODUCTION Programmable logic controllers (PLCs) are especial type of systems used to control processes and machines. They have been put forward in the early 1970s to substitute the extant relay control logic that has been outworn and valuable for implementing systems at that span. Moreover, PLCs exhibits higher reliability, flexibility, better communication possibilities and faster response time. As yet, PLCs have been concern for industrial control engineers that developed, introduced and standardized their own design methods and programming languages. However, issue and obstacles in the study and experiment on PLC is the rapid pace of PLC technological development, with new layouts and innovations continually being introduced by manufacturers. Future, PLCs are faithful industrial controllers, but once purchased for laboratory use cannot be engaged for a wide range of other advantageous applications. Costs acquired in the setting up of absolute and modernized PLC laboratory facilities, and equipment are, as a result, very high.[1] [5] A. Concept of PLC An embedded system is frame to operate one or a few dedicated functions normally with real time computing constraints. It is enclosed as part of a complete device usually including hardware and mechanical parts. By comparison, a PLC is arranged to be adjustable and to accommodate a All rights Reserved

2 range of end-user demands for industrial control application. Embedded systems control multiple devices in use today. One or more main processing cores controls embedded systems that are commonly microcontrollers. The essential characteristic is being dedicated to handle a special task that may need very powerful processors. Since the embedded system is dedicated to precise tasks, design engineers can improve it to reduce the cost and size of the product and improve the reliability and performance.[5] B. Concept of Embedded systems Embedded system is based on computer technology, which makes it suitable to fit for different application system, from other aspect; it is a unusual computer system that has disciplinary requirements in power consume, reliability, size and cost. It is the result of combination of technology development, such as electronics, computer, communication, semiconductor, and automation control. Embedded system has been extensively used in telecommunication, computer network, industrial control fields, consumer electronic product, aeronautics, medical apparatus and national defense industrial fields, and so on. The features of embedded system are as follows: Embedding, special system, extended interface.but there are still problems in implementing embedded system in control field that include: The design problem of embedded control system, the reliability problem of embedded control system, the compatibility problem of embedded control system.[4] C. Concept of Embedded PLC Being Studying the features and conception of embedded system and PLC, in this paper the expansion of low-cost embedded PLC for small scale industry application is proposed. The visionary design of embedded PLC combines the benefits of PLC and embedded system together. The architecture of embedded PLC is being developed by the LabVIEW with VB Module for ARM Microcontroller. The work of this development involves: 1) Based on embedded system technology, design a PLC. 2) To expand a model of embedded PLC. 3) One dedicated application to be implementing on embedded PLC. [1][2] II. IMPLEMENTATION OF EMBEDDED PLC The aims of the embedded PLC are that it must reinforce the sub-disciplines of computer programming, software engineering, and panel wiring. While the basic system must support digital Input/Output, also it should be supportive to analogue handling. The detailed objectives being that embedded PLC should be safe, low cost, can be interfaced to computer, integrate an industrial standard. On the other hand, embedded PLC should support IEC programming languages. A. Hardware Design The ARM microcontroller is selected to develop embedded PLC because it is broadly used across many embedded designs because of its low price, low power consumption, and wide variety of peripherals for many of the major vendors. Extension to this, we are using the LabVIEW Embedded Module for graphical programming to the ARM microcontroller. At the same instant, the properties of the LPC2378 microcontroller is used as a determinant specifications and features of embedded PLC, as shown in Fig. 1 and Table I respectively All rights Reserved 826

3 Fig 1. Main components used for developing Table 1 Specifications and feature of ARM LPC2378 Sr No Feature ARM7 LPC 2378 (72 MHz) 1 Flash memory 512Kbytes 2 SRAM 32Kbytes 3 Digital Input 8, sink/source 24V DC 4 Digital Output 8 Sink upto 200mAeach, 24V DC 5 Analog Input One 10 Bit resolution, input range 0-10V 6 Analog Output One 10 Bit resolution, output range 0-10V 7 Serial Port RS Power supply Single 3.3V power supply The signals (input and output) from the Microcontroller board are limited at 3.3V, therefore it is redesign of input and output of the embedded PLC that will allow to custom external industrial equipments, as shown by Fig. 2. Fig 2 Architecture of Embedded PLC B. Software Design Five programming languages for programmable control systems is presently defined by IEC are : LD (Ladder diagram), FBD (Function block diagram), ST (Structured text, similar to the Pascal programming language), SFC (Sequential function chart) and IL (Instruction list, similar to assembly language).[6] In this work, the FBD programming language is used for control of embedded PLC as the LabVIEW Embedded Module for ARM Microcontrollers is a extensive graphical All rights Reserved 827

4 environment for embedded design. This module combines the LabVIEW graphical development environment and ARM microcontroller. This module frame on LabVIEW Embedded technology which promote dataflow graphical programming for embedded systems and contain hundreds of analysis and signal processing functions, integrated Input/output, and interactive debugging interface. With the Embedded Module for ARM Microcontrollers, we can enhance linking and view live front panel using JTAG, serial, or TCP/IP [6]. The Embedded Module for ARM Microcontrollers incorporates the LabVIEW C Code Generator, which generates C code from the LabVIEW block diagram [6]. For the creation of FBD language, we use the avariable tools in LabVIEW, as shown in Fig. 3. A basic function of FBD language is organized according to IEC standards required for PLC which can be outlined as shown in Table II and Fig. 4 respectively. Fig 3 The example of creating function of FBD language Table 2 Basic functions of FBD language Instruction Addition Symbol Substration Multiplication Division Equal Not equal Equal to zero Greater than Less than ANDing NOT ORing Up All rights Reserved 828

5 Fig 4 Basic functions of FBD was developed for usage For model testing, the system architecture has been implemented by testing some experiments like basic gates (AND, NOT, OR). Architecture, operation, and programming language of PLC is observed. The laboratory effort included developing a FBD based, testing via the simulated model, after transferring program to the embedded PLC, then interfacing external equipment to embedded PLC, and finally executing the PLC program on the physical system. Fig.5 shows steps of implementation of embedded PLC.[2] Fig 5 Steps of implementation of embedded All rights Reserved 829

6 Fig 6 Application of embedded PLC in irrigation System The example of interfacing industrial equipment to embedded PLC: Fig. 6 shows the application of embedded PLC in irrigation system [7]. At the input side the content of soil moisture is determined by ATK SM (soil moisture sensor). If the soil moisture is below 14% (value controlled by FBD language) the data is proceed through embedded PLC & the water pump will start through relay and will spray water in the field. Similarly if the temperature in the field exceeds 29 C is senses by LM35 then the output is produced by the LED indication. Fig.7 shows the function block diagram for the system. The FBD code for the proposed system is generated by LabVIEW Embedded Module used for ARM with the help of LabVIEW software.[3] This diagram gives the backend view for proposed system diagram. The backend defines internal structure of front window. It shows the inputs and outputs associated with ARM for irrigation system. From the function palette components are selected. Fig 7 Backend for irrigation system III. EVALUATION OF EMBEDDED PLC After completing various laboratory exercises, we found possible conditions broadly determine the effectiveness of the embedded PLC. For each statement, we verified the condition. The hardware are safe. The embedded PLC setup is comparatively easy to understand. The programming language has typical functionality such as logic, latching, timing, mathematics, etc. Input and output were appropriate. The embedded PLC is able to interface with PC. To simulate the functionality of designed program before actual usage. PLC program file was effortlessly downloaded to the embedded PLC. Able to interface with common industrial electrical components. Reliability and Stability of embed PLC is All rights Reserved 830

7 Appearance of embedded PLC motivates to usage and experiment.. The simplicity of Embedded PLC along with good reliability, which demonstrates the success in generating. Also by using this Embedded PLC various dedicated applications can be implemented, as this Embedded PLC can sustained to better accuracy without using actual PLC IV. CONCLUSION A cost-effective resolution for an embedded Programmable Logic Controller (PLC) is the use of an Integrated Circuit (IC) that is a complete PLC. Using a single-chip PLC, development time is extremely reduced because the software drivers for numerous types of Input/output are already embedded on the chip. Once the system I/O has been defined, the appropriate interface circuits can be further added to the design and programming can be completed easily using the functional block diagram programming language and software such as LabVIEW. The implementation of the conceptual embedded PLC for controlling the irrigation system with the flawless combination of the LabVIEW software and the ARM Microcontroller module is discussed in this paper to test real time application. The flexibility of the proposed PLC makes it relatively easy and less costly to handle PLCs due to their variety and rapid change. The basics of PLC, its programming languages were discussed and a flexible, low cost, low power consuming PLC with a easy graphical interface has been designed using the ARM microcontroller V. REFERENCES [1]Pornjit Pratumsuwan and Watcharin Pongaen, An Embedded PLC Development for Teaching in Mechatronics Education, (KMUTNB), th IEEE Conference on Industrial Electronics and Applications. [2]Ms. Sneha Goyanka, Prof.Mrs. Rohita Jagdale, Survey of PLC Development on Embedded Platform International Journal of Electronics Communication and Computer Engineering (Volume 5, Issue (4) July),Technovision-2014 [3]Chetana N. Gangurde, Rupali S. Khule, Implementation of Embedded PLC for Batch Mixing System by using ARM Controller, IJSRD - International Journal for Scientific Research & Development Vol. 3, Issue 07, 2015 [4] Data books of ARM7/ARM9 J. Staunstrup and W. Wolf, editors, Hardware/Software Co- Design: Principles and Practice, Kluwer Academic Publishers, [5] Programmable Logic Controllers, Fourth Edition, W. Bolton, Elsevier Newnes publications. [6] Getting Started with the LabVIEW Embedded Module for ARM Microcontrollers 1.1 For the Keil MCB2300 [7] Maha M. Lashin, Different applications of programmable logic controller (plc) International Journal of Computer Science, Engineering and Information Technology (IJCSEIT), Vol. 4,No. 1, February All rights Reserved 831

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