Customized RTU for Local and Remote Supervision

Transcription

1 AUSTRALIAN JOURNAL OF BASIC AND APPLIED SCIENCES ISSN: EISSN: Jurnal hme page: Custmized RTU fr Lcal and Remte Supervisin 1 Mayssa Hajar, 2 Raed ElRafei, 3 Khaled Muchref 1 Lab Instructr and PHD Student, Lebanese University, Electricity and Electrnics, Faculty f Engineering, Tripli. Lebann 2 Graduate Engineer, Lebanese University, Electricity and Electrnics, Faculty f Engineering, Tripli. Lebann 3 Assistant Prfessr, Lebanese University, Electricity and Electrnics, Faculty f Engineering, Tripli. Lebann Address Fr Crrespndence: Mayssa Hajar, Lebanese Univsersity, Faculty f Engineering,Electrcity and Electrnics Departement, Tripli, Lebann , mayssa.h@gmail.cm. A R T I C L E I N F O Article histry: Received 26 August 2016 Accepted 10 Octber 2016 Published 18 Octber 2016 Keywrds: Remte terminal unit, SCADA, PLC, telemetry. A B S T R A C T Telemetry is the science f gathering infrmatin at sme remte lcatin t be examined and recrded [1]. When telemetry is used t bth: mnitr and cntrl, SCADA (Supervisry Cntrl and Data Acquisitin System) is ften used t describe the System. This paper presents a new design f SCADA that wrks remtely. Telemetry system cnsists f three parts: central unit, remte terminal unit (RTU) and cmmunicatin media. The mst imprtant part f this system is a lw cst RTU based n a Prgrammable Lgic Cntrller (PLC), which can be custmized accrding t the user s needs. This RTU is cnceived t cllect data frm the field f instruments & sensrs and transmits the infrmatin t SCADA installed in a central cntrl rm thrugh wire/wireless cmmunicatin systems and lines, and t receive cntrl cmmands frm hst cmputer t cnduct nline cntrls in real time. The main rle is accmplished by the PLC (XGT 5000) with its extended mdules in rder t cmmunicate with the different system parts. The SCADA design is develped in Vije Designer sftware. Mdules used are: Real Time Clck Mdules t guarantee exact histry f data, Cmmunicatin Mdules: RS485 t cmmunicate with lcal SCADA, an Ethernet Mdule fr remte SCADA, and an analgue mdule t extend the acquisitin t analgue signals. In additin a Pwer Meter is added t the system t prve sme featured prperties f such supervisry tl. As ne RTU can cmmunicate with the remte SCADA via an IP address, multiple RTU can be used having each ne a unique IP. This design is dedicated t industrial applicatin and can be easily extended t supervise multiple mdules, and hence can be used in diagnsing and mnitring machines and systems, and cllecting data fr fault and errr predictin. INTRODUCTION In General, telemetry system cnsists f three parts, which are: central unit, RTU and cmmunicatin media (Wikipedia, 2016). The remte terminal unit is made up f three majr parts: sensrs, micrprcessr r cntrller, cmmunicatin tls (Wikipedia, 2016). Already designed RTU are all based n micrcntrllers, which allw them t be used in general applicatin. Hwever, when an industry dedicated RTU is needed, the tugh aspect f the industry envirnment shuld be taken in cnsideratin. On the ther hand, the PLC is the mst used cntrller in such dmain. S ur cntributin is t design an RTU based n PLC with all its extensin mdules and cmmunicatin tls. This RTU is implemented in a cmplete SCADA system. First this RTU is mnitred by a lcal SCADA within the n-site supervisin statin, then it cmmunicates with the remte SCADA via Ethernet t cmplete the supervisry system design, nce the cnnectin between the remte SCADA and ne RTU is established, we can assure that the remte supervisin statin can be cnnected t multiple RTUs. Open Access Jurnal Published BY AENSI Publicatin 2016 AENSI Publisher All rights reserved This wrk is licensed under the Creative Cmmns Attributin Internatinal License (CC BY). T Cite This Article: Mayssa Hajar, ElRafei, Khaled Muchref., Custmized RTU fr Lcal and Remte Supervisin. Aust. J. Basic & Appl. Sci., 10(15): 48-54, 2016

2 49 Mayssa Hajar et al, 2016 In this paper, we will present the hardware and sftware design f the n-site supervisin statin in sectin 2. In sectin 3 the sftware and hardware design f the central remte unit are presented. Finally, the results are discussed in sectin 4 and the perspectives are suggested in the cnclusin. 2. Hardware Design and Sftware f the n-site supervisin statin: The rle f the RTU is t cllect data frm the site, by cmmunicating with the sensrs and the different instruments present n the field. We cnceived a special RTU that relies n the PLC t accmplish this task. The prpsed hardware design f the R.T.U is shwn in figure 1: Fig. 1: The blck diagram f the prpsed R.T.U I. Hardware Design: Thus, the n-site supervisin statin is cmpsed f the fllwing cmpnents, In rder t clarify the rle f each cmpnent a brief definitin is given abut it belw: PLC f type XGB Analgue and Digital Mdules Ethernet mdule. RTC (real time clck). Lcal SCADA (runtime). a) Plc Xgb: PLC is the main cmpnent f the prpsed RTU, it cntains CPU that cllect the data frm the sensrs, prcess it and give it t the cmmunicatin part fr delivering it t the central unit, and cntains a vlatile memry and nnvlatile memry fr prcessing and string prgrams and data. The used PLC in ur applicatin is PLC XGB which is manufactured by the LS Cmpany (Krea). Fr mre details the reader is recmmended t view the reference ( XGB is a mdular type that can be extended by different type f mdules such as the Expansin I/O mdule and the Cmmunicatin mdule that are used als in this applicatin. This prperty f the PLC gives the user an ptin t extend the capability f the RTU t manage and mnitr a larger number f instruments and sensrs and thus a wider field can be perated frm the same statin. In additin the variety f mdules that can cmmunicate with the PLC make this RTU custmized t the user s need. b) Analgue and Digital Mdules: PLC uses digital r analg input/utput mdules t cntrl machines, prcesses, and ther cntrl mdules.the used XGB cmprises 12 input and 8 utput digital mdules and we can add analgue mdules t cver the need f the system. In this applicatin the XBO-AH02A analg I/O ptin bard is used t add an analg input and utput t the PLC. It cntains ne Channel Analg input, ne Channel Analg utput

3 50 Mayssa Hajar et al, 2016 (Vltage/Current) that prvides 2 ranges (4~20mA, 0~20mA) f current I/O and ne range (0~10V) f vltage I/O ( c) Ethernet Mdule: XGB Fast Enet I/F mdules (XBL-EMTA) is an interface mdule used t cmmunicate data between higher level system such as hst PC and PLC. It supprts pen Ethernet and prvides data sending/receiving by using Mdbus TCP/IP prtcl ( In the prpsed RTU, XBL-EMTA prvides the cmmunicatin part that cnnects RTU t the remte SCADA. This wireless cnnectin is very imprtant in this cntributin. In fact, the remte SCADA can cnnect t multiple RTUs simultaneusly via their Ethernet mdules, having each a unique IP address. Once ne cnnectin is established between the remte supervisin statin and ne RTU, it is guaranteed t accmplish a cnnectin with the same prtcl and using the same mdule amng the remte SCADA and multiple RTU in multiple lcatins, figure x can easily clarify this cncept. d) RTC: The RTC used in this applicatin is the XBO-RTCA which is the cmpatible real clck mdule with the XGB PLC. Such mdule is needed in SCADA system t determine the exact time f any event. Fig. 2: Remte SCADA cmmunicating with multiple RTUs in different Lcatins via Ethernet Mdules e) Lcal SCADA: The lcal SCADA is an applicatin develped n the n-site PC, which is cnnected directly t the RTU via a serial cmmunicatin RS485 that is a physical layer f the prtcl Mdbus. The Lcal SCADA rle is t gather data frm RTU and generally prvide an interface t: display infrmatin, cntrl the remte sites, present peratinal status, shw histrical data and manage alarms. The SCADA used is develped n the sftware Vije Designer that is a state-f-the-art sftware applicatin develped by Schneider electric. This sftware allws t create Human Machine Interfaces (HMI) and prvides all the tls needed t design a prject, frm the acquisitin f data t the creatin and presentatin f animated drawings. In additin t the already listed mdules, a pwer meter is added t cmmunicate directly t the lcal SCADA t prve this ptin given by the lcal SCADA applicatin. The used pwer meter is PM201 manufactured by Schneider, it measures many electrical parameters like the vltage, the current, the frequency and the energy cnsumptin, the remaining characteristics are given in (Schneider-electric.cm). An imprtant ptin in lcal SCADA is that we can create r calculate internal variables nt prvided by the RTU and ther devices cnnected t it. It can send internal r external variables t remte SCADA, which can cmmunicate t RTU via Ethernet mdule, by sending these variables t the memry f the RTU. II. Sftware design f the RTU cmpnents: The RTU cmpnents (its different mdules) need t be cnfigured prperly t cmmunicate with the cntrller element (PLC) in rder t accmplish the RTU functinality. This can be dne in these few steps: a) Prgramming PLC: The XGB PLC can be prgrammed by the XG5000 sftware develped by the manufacturer [3]. The PLC shuld be prgrammed t perfrm the peratin f data cllectin via digitals and analgue mdules cnnected t PLC, and transmit these data t cmmunicatins media (serial cmmunicatin and Ethernet cmmunicatin).

4 51 Mayssa Hajar et al, 2016 b) Cnfiguratin serial cmmunicatin Mdbus RS485: The RTU presented by its cntrller element, the PLC, can cmmunicate with lcal SCADA (the applicatin n the cmputer) via serial MODBUS cmmunicatin. The XGB PLC needs a mdule t deal with MODBUS cmmunicatin. Thus, the mdule (Cnet I/F) is integrated, but needs t be cnfigured by adjusting the speed, the statin number and such infrmatin ( c) Cnfiguratin Ethernet mdule cmmunicatin: RTU can cmmunicate with remte SCADA via Ethernet cmmunicatin, the extensin mdule used is XBL-EMTA, which shuld be cnfigure accrding t the TCP/IP prtcl ( d) Lcal SCADA sftware: The lcal SCADA analyzes and displays the data acquired frm RTU and PwerMeter and can send data t remte SCADA via Ethernet mdule cmmunicatin. The sftware was designed and implemented in Vije Designer as shwn in figure 3. Fig. 3: Lcal SCADA Interface 3. The design f Remte SCADA (central unit): The main functin f the central unit is t receive, prcess stre and display the data received frm RTU. The implemented hardware cnsists f PC with static IP address. Fig. 4: Remte SCADA As already mentined the lcal SCADA acquires data frm PLC and ther cmpnents, new variables can als be calculated via the prgram f this entity. Thus, it cntains larger amunt f data than the RTU and its cntrller (PLC).But the lcal SCADA cannt cmmunicate directly with the remte central unit, the cmmunicatin shuld be via the RTU. S, all the data sent frm the lcal SCADA t the Remte SCADA will pass via the internal memry f the cntrller f the RTU (PLC).

5 52 Mayssa Hajar et al, 2016 As the remte central unit supervises many entities at the same time, each entity is an RTU in a specific lcatin, lgically, the remte SCADA shuldn t receive all the data cntained by the lcal SCADA, s, the parameters displayed by the sftware f the remte SCADA are the mst essential nes f thse displayed by the lcal SCADA. RESULTS AND DISCUSSIONS This new design f a remtely supervisry system is applied in a small experiment where a lw cst and mdular RTU is implemented t cmmunicate with lcal and remte SCADA. Fig. 5: the designed and successfully Implemented RTU The serial cmmunicatin is added t this unit t cmmunicate with the PC where the lcal SCADA applicatin is running. While the Ethernet mdule is used t guaranty the wireless cmmunicatin with remte central unit. Figure (6) shws a cnnectin between R.T.U and lcal SCADA ver a serial cmmunicatin and between RTU and remte SCADA ver a LAN. A ruter was added t allw access t LAN and internet Netwrks. Fig. 6: Lcal SCADA Cmmunicating with the RTU and the Pwer Meter

6 53 Mayssa Hajar et al, 2016 As shwn in figure 6, the lcal SCADA cmmunicates with the RTU and the PwerMeter(PM210). In fact, we can add ther cmpnents cmmunicating with the lcal SCADA t have mre measurements and thus cllect mre data frm the supervised system. Cnsequently, the n-site supervising statin is extendable t cver all the need f any user. Within the RTU, the PLC cllects data frm all the sensrs and the mdules cnnected t it. In this applicatin, the data delivered by the RTU are: -temperature frm the analg mdule -actual time and date frm the RTC -start and stp utput cntrl frm the PLC The pwermeter cmpnent delivers many parameters. In ur experiment, we have chsen: -real pwer cnsumptin -frequency -ttal pwer factr -the current and the vltage in each phase. The lcal SCADA cllects the data frm the RTU and additinal cmpnents, and can calculate new variables deduced frm the cllected data. In this applicatin, we have added the sum f current in the three phases. Fig. 7: Result n lcal SCADA interface. Fig. 8: Result n remte SCADA interface The remte SCADA cmmunicates with the RTU t cllect data, sent frm lcal SCADA, and t send back the crrespnding cmmands. The cllected data sent frm lcal t remte SCADA, via the RTU, can be either cming frm RTU r PM210 r internal variables created in Lcal SCADA. In ur applicatin, the parameters displayed in the remte SCADA are nly five, which are the mst imprtant t be mnitred. In fact, the remte SCADA, as mentined befre, can be cnnected t mre than ne RTU and thus supervises multiple wrking system in the same time. This can add t this supervisry design system wideness and extensibility: ne remte

7 54 Mayssa Hajar et al, 2016 supervisin system can mnitr and cntrl multiple systems simultaneusly in different lcatins which are all distant frm the supervisin statin. Cnclusin: In this paper a telemetry system was designed and implemented: it is based n an RTU that cmmunicates with a lcal and a remte SCADA. The remte terminal unit is based n a PLC with sme additinal mdules: it is characterized by its lw cst, its mdular aspect, and its dedicatin t industrial applicatin. The lcal SCADA supervises the system by cmmunicating with the RTU and ther cmpnents, and the remte SCADA receives data frm lcal SCADA and cntrls the system via RTU. This design allws the user t mnitr and manipulate industrial systems lcally and remtely using simple and cheap devices, with the pssibility t extend the supervisin (distant r n-site) n multiple systems wrking at the same time. Finally, this supervisry system can be used t study systems and machines behavir, and cllected data that can be prcessed in different ways, s they can lead us t study and predict errrs and then prevent systems frm failure. REFERENCES Dan Eisenreich Brian DeMuth, Designing Embedded Internet Devices. Imprint f Elsevier Science (USA). Wikipedia, Remte Terminal Unit: http//en.wikipedia.rg/wiki/remte_terminal_unit. XGB+Analg_Manual_ENG_V1.9_ XGB Fast Ethernet I/F Mdule5 Schneider-electric.cm