DESIGN OF MULTI-CHANNEL DATA ACQUISITION AND PROCESS CONTROL MODULE

Transcription

1 Volume 116 No , ISSN: (printed version); ISSN: (on-line version) url: ijpam.eu DESIGN OF MULTI-CHANNEL DATA ACQUISITION AND PROCESS CONTROL MODULE Subashini V 1 Eswaran P 2 Lawrence Danieal R 3 1,2,3 Department of ECE, SRM University, Chennai, India 1 subashini_ven@srmuniv.edu.in Abstract: This paper proposes the design of a 8- channel real-time data acquisition and process control module for various industrial and commercial process control application. This system uses single master and 8 slave. The master and slave are connected through I2C protocol. The function of the master is to interface PC and slave, for transferring data from slave to PC and data storage. The slave s form a standalone module, which can be a reconfigurable program to cater the application requirement of the user based on individual process requirement. Usually, a single channel data acquisition module is used for an individual channel. The proposed system is developed using ATMEGA 328 and an open source software. The developed system was simulated in Proteus IDE, and the 8 channel data acquisition module was developed and tested for various data rate condition. The developed system meets desired performance and shows reliable functionality. Keywords: Data Acquisition, I2C, Master/Slave, Multi-channel. 1. Introduction Data acquisition is the process of measuring and collecting a physical or electrical phenomenon which is employed in many fields such physical signal sensing and monitoring applications. Continuous acquisition of data from the process control is challenging task, and multi-channel data acquisition by the single is much more complex. Most of the system uses a single master that controls a single slave to acquire data from that particular slave has many drawbacks such as loss of data during transmission and delay in the process. Considering the drawbacks while using single master and single slave configuration, a single master, and multi-slave configuration is developed to overcome them by not only collecting the real time data but also controlling. Xiaolin Fang et al. [1] developed data sharing for data collection among multiple applications is an efficient way to reduce communication cost in WSNs. Data sharing problem to transmit as less data as possible over the network was discussed. The problem is addressed in polynomial time. Also, dynamic programming algorithm is provided for special instance. M.I.M.Bakri et al. [2] developed air quality can be monitoring and data collection system. Application of high sensitivity sensors helps to improve the optimization of data acquisition systems to collect and transfer data. WojciechAndrysiewicz et al. [3] implemented an I2C compatible serial interface for asynchronous ADCs that output data irregularly in time. The device contains I2C hardware master-transmitter functionality and is capable of operating fully autonomously in I2C bus communication system. In particular, the asynchronous ADC with proposed I2C interface can initiate data transfer on the bus when new data are available on the converter output. TonmoySarker et al. [4] implemented a data acquisition system in flights and unmanned aerial vehicles that collect and shares data for process control. Vasant Raj Mutha et al. [5] developed a data acquisition system such that the environment is monitored by both digital and analog sensors. Mohammad Haizad et al. [6] developed a data acquisition system that is an open source software using a micro helps in automation and control of the system. Maitraye Das et al. [7] designed a health support system that employs a data acquisition system to collect vital signals from the body in real time and the health status is 37

2 updated on a mobile device, which may be useful for emergencies. 2. Design of multi-channel data acquisition system The proposed system uses single master and 8 slave s connected through an I2C bus and communicates using serial protocol. The block diagram of multichannel data acquisition system is as shown in Fig. 1. The slave device functions to the corresponding user interface commands irrespective of the master s state. The user can interface either an analog/a digital signal to the slave that monitors and controls the process according to the user program written in the slave. Since the slave device is connected to the master through I2C, the data collected will be stored in an external user interface through the master for further processing. Figure.2 Implementation of single-channel data acquisition system 2.2 Slave Controller The slave uses a 8 bit ATMEGA 328 micro, which implements the data and control busses to communicate with the user interface through the master device. An ARDUINO UNO development board is used as the slave, in which 2 analog and 2 digital I/O pins are used for data acquisition and process control respectively. Figure.1 Multi-channel data acquisition system The implementation of the single-channel DAQ system is shown in Fig.2. The sensor receives inputs from various process or sourcess which are processed by the slave and in turn the slave sends the control signals to the plant to control the process. 2.1 Master Controller The master is basically a 8-bit micro using ATMEGA 328 that sends command/control signal to the slave and also provides communication to an external interface to share the acquired data from the slave to the database in PC/IoT. The master- interface slave interface and master-external employs an I2C communication. Figure.3 Execution flow of Master-Slave communication 38

3 Loop Slave i= 1 to 8 No Start Assign address to all slave Master sends Request to Slave (i) If i h Slave acknowledges master Yes Master Reads Data From Slave 3.2 Slave Device Operation The flow chart of slave devicee operation is shown in Fig.4, and the steps involved in the process are as follows. Step 1: Start. Step 2: Time is set in RTC Step 3: Data value to be counted is set. Step 4: Initiate the counting process Step 5: Count the data received in the slave. Step 6: Check if the set time is reached. Step 7: If set time is reached, GOTO Step 1. Data Received successfully Store data in PC Master sends request to next slave If all Slave s are read Yes Figure.4 Execution flow of Slave 3. Execution algorithm 3.1 Master-Slave Communication No No The flow chart of master-slave communication is shown in Fig.3, and the steps involved in the algorithm are as follows. Step 1: Start. Step 2: Initialize slave s and all devices. Step 3: Assign address for all slave devices. Step 4: Master sends a request to each slave by passing the address to designated slave using round robin algorithm. Step 5: The corresponding slave device with matching 7-bit address sends an acknowledgment to the master. Step 6: Master requests data from the particular slave device. Step 7: The slave sends the data to the master. Step 8: If data is received successfully, the master passes the next slave device address. Step 9: Repeat step 4. Yes Step 8: If set value is reached, GOTO Step Results and Discussions The proposed system is designed and implemented in Proteus ISIS environment and simulated for various test cases using the developed algorithm. In this individual slave was tested for its performance and have been extended for a single master and 8-slave s. For simulation, the input data is generated using IC555 in astablemultivibrator configuration. Two LEDs (Red and Green) are used to indicate the control operation by sending control signal for switching ON/OFF. 4.1 Case 1 stop the process else When a pulse input is given to the slave, the device starts counting the pulses. When the pulse count process is initiated, the process is switched ON and the task is indicated by glowing a green LED and it is shown in Fig

4 Figure.5 Execution of count operation in slave 4.2 Case 2 When the input pulses count in slave reaches the set limit/value, it stops counting the pulses and the process is in STOP condition and is indicated by glowing a red LED as shown in Fig.6. Figure.6 Execution of count stop operation in slave 4.3 Design of 8-channel data acquisition system The data acquisition system is designedd in Proteus ISIS environment. A master r controls 8 slave devices establishing a communication between them which is shown in Fig.7. The input to the slave devices is given from an astablemultivibrator. The input pulses are counted by each slave device, and then the count is regularly updated. The process is indicated by a bidirectional LED. Figure.7 Schematic of 8-channel data acquistion system 4.4 Implementation on Hardware Fig. 8 shows the implementation of a master and 8 slave devices (SL) that are connected through I2C. Outputs from individual astablemultivibrators of various frequencies are given to each slave as input. Initially, when the counting process starts and also during the pulse count operation, the condition is indicated by green LED and when the pulse count operation completes, the system stops and it is indicated by a red LED. This system is reset automatically when the set time limit is reached and continues for next cycle. 5. Conclusion The 8-channel real-time data acquisition system is designed, developed and implemented in simulation environment as well as tested using hardware prototype. The developed system is tested using the standard test signals developed for that purpose. Test results of the developed 8-channel data acquisition system show seamless data count operation as well as I2C communication between the master and PC. The slave shows reliable operation in acquiring the data and producing a control signal to the plant. Further, this work will be extended for the development of this module, compatible for IOT application. References [1] Hong Gao, Xiaolin Fang, Jianzhong Li, And Yingshu Li "Data collection in multi-application sharing wireless sensor networks," IEEE Transactions on Parallel and distributed systems, Vol. 26, No. 2, February [2] M.I.M.Bakri.A, Zakaria..S, M.M.S.Zakaria, L.M.Kamarudin, A.Y.M. Shakaff, F.S.A.Saad, M.F.Ibrahim, M.H.M.Razali plant bio-absorber for ammonia gas absorption using i2c interface data acquisition system. Electronic design (ICED), nd international conference pg. No , Aug [3] Mrs.P.Jegadeeshwari, Miss.S.Seema, Control And Directing Of Wireless Load Using IVRS by DTMF, International Innovative Research Journal of Engineering and Technology, Vol. 1, no. 3, March [4] Wojciech Andrysiewicz, Dariusz ko Scielnik, Marek mi Skowiczagh university of science and technology, I2C hardware master serial interface 40

5 for asynchronous ADCS,IEEE communication systems, Vol. 50, No.12, Oct [5] Tonmoy Sarker, Purnota Hannan, Shahidul Alam Shahed, Naimur Rahman, Syed Nazmus Sakib, Conceptual design of a low cost flight data acquisition system for analyzing flight behavior of small unmanned aerial vehicles, Computer and Information Technology (ICCIT), 19th International Conference, Dec [6] Vasant Raj Mutha, Narendra Kumar, Parikshit Pareek Real time standalone data acquisition system for environmental data, Power Electronics, Intelligent Control and Energy Systems (ICPEICES),IEEE International Conference, Jul [7] R.Shabin Vinu,K. Mayavady, Detection And Isolation Of Power Exhausting Attacks To Secure Data In Wireless Sensor Networks, International Innovative Research Journal of Engineering and Technology, March [8] Mohammad Haizad, Rosdiazli Ibrahim, Anas Adnan, Tran Duc Chung "Development of lowcost real-time data acquisition system for process automation and control," Robotics and Manufacturing Automation (ROMA), nd IEEE International Symposium, Sept [9] Maitraye Das, Sunandita Sarker, Syeda Lammim Ahad, A novel health support system with biometric data acquisition device, Computer and Information Technology (ICCIT), th International Conference, Dec [10] Bollam Eswari, N.Ponmagal, K.Preethi, S.G.Sreejeesh Implementation of i2c master bus on FPGA International conference on communication and signal processing, Apr 3-5, [11] Eswaran.P, Aswin Kumar., "Conceptual design and development of water metering system for multiple family residential buildings," International journal of advanced compute Research, Dec [12]Eswaran.P, Aswin Kumar "Design and development of automated water distribution and metering system for residential buildings," Computational intelligence & Computing Research (ICCIC), Dec

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