Hello learners. Welcome to this topic on architecture of SCADA. The following components are normally used in Scada systems. Local processes, operating equipment, PLC's, RTU's, IED's are intelligent electronic devices, master terminal unit, host computers, personal computer with human mission interface. The basic SCADA architecture is depicted in the block diagram forest. There is a difference between this SCADA and distributed control system, DCS. DCS is regularly deployed in the job sites. SCADA's geographic coverage is a much larger area. This provides the support to TCP, I P, UP and other IP based communication protocols and the industrial protocols like Modbus TCP, Modbus over TCP, Modbus over UDP. The function over cellular, private radio or satellite networks. When the architecture of SCADA is complex, there are many different types of wired and wireless protocols and media are for getting data to the monitoring site. This permits the deployment of IP based powerful SCADA networks like landline mixed with cellular and satellite systems. SCADA communication can be done with various ranges of wireless and wired media. The selection of the communication depends on several factors. Those are remoteness, Presently Available Communication Network, Polling Frequency and Data Rates. These factors are important to decide, discard architecture. From the review of SCADA evolution, we will be able to understand many security concerns. The typical system consists of the following Feeder Remote Terminal Unit or FRTU, in a place where RMU is there. Micro FRTU in a place where distribution transformer is there. Multi Function Meter or MFM, in a place where distribution transformer is there. Current Transformer CT in a place where DTR is there. Fault Past Indicator or RFPA in the overhead line are cable line. Modern For FPA, [INAUDIBLE] it is in the overhead line. Data controller unit that is DCU, in places where auto recloser and sectionalizer are there. GPRS Modem in places where auto recloser and sectionalizers are there. Antenna, SCADA are DMS at control center. RTU, Network Switch. The functions of the DMS are located at the control center, enables automatic and manual operations of the network devices, monitor all the parameters of interest. Substation RTU collects all the data pertaining to substation. The same data received by the control center via MPLS-VPN network. Status and indications data from 11kv distribution assets like Ring Main Units through FRTU, Fault Passage Indicators. Sectionalizers are acquired by data controller unit or DCU. Communicating to the control center through appropriate connectivity like fiber optic cable or wireless mobile networks. Stand alone fault passage indicators are to be communicated to the control center using 3G, CDMA, GPRS modems. Remote Visual Data Units or RVDU, enables monitoring from other places like HQ and designated office. Proper provision to be made for future editions growth expansions. SCADA, DMS control center will exchange data using ICCP with State Load Dispatch Center or SLDC of the state. The Data recovery or DR, will be a repository of all towns where SCADA, DMS is going to be installed. In the specification of the DMS, the functions mentioned can be classified into two different categories. Critical functions and non-critical functions. In critical functions, every single such function must have enough hardware and software redundancy. This will enable automatic change over from field path to healthy path during hardware or software or both failures. This will not interrupt the functions for a period exceeding automatic transfer time defined in this specification. Generally, the following are to be classified as critical functions. All SCAD applications, Information Storage and Retrieval. All DMS applications, data exchange among the contractor supplied SCAD or DMS system. IT system established under our R-APDRP. Web server applications and security applications, Network Management System or NMS, Data Recovery Function. The non-critical function may not be supported by hardware and software redundancy. And can be suspended in case of the non availability of corresponding hardware. Some of the non critical functions are Dispatcher Training Simulator, database modification and generation, display modification and generation. Report modification and creation, data exchange with remote VDU's if any. Detailed control center architecture is shown in the figure. The proposed system consists of the following SCADA-DMS-OMS server, Real-time data acquisition. FEP Server, Front End Processor, for polling of RTU and FRTU. NMS server Network Management Server, maintain performance, resource usage and error statistics of all the equipment that is servers, workstation consoles, devices, telephone circuit interface equipment. And all SCADA/ DMS gateways, routers, etcetera. And present this information via displays, periodic reports and on demand reports. ICCP Server for communication to other control centers such as SLDC and DR center. Web server for the web clients such as RVDU. Let us try to understand how the connectivity is getting established from the field to SCADA in 11kv and downstream systems. Now first for example, let me assume that the SCADA-DMS-OMS Control Center is at a place called A. And there are four substations which are called as A, B., C & D. Now, if you happen to see these four substations are connected to the SCADA, following the line shown in dotted with green color. And similarly, substation to substation are also connected through the same line which is connected through an OFC cable. This is there fiber optic communication network. Almost it is about 60 km [INAUDIBLE]. Now, when we try to go for the downstream, we do how, from each substation, we held guard the outgoing lines which has many fault passage indicators, auto reclosers and sectionalizer. This is the fault passage indicator. This is the auto recloser and these are all these sectionalizer. And also you have ring main units, from there the cable comes and cable goes out and then it goes to the loads. Now, these are all getting connected to these substations through optic fiber cable and each and every equipment thus is getting connected to [INAUDIBLE]. Now, this indicates the total connectivity between the in the equipment say sectionalizer or auto recloser or fault message indicator. Through ring main units to the substations [INAUDIBLE], this is how the typical field SCADA connectivity is established. This is how all the equipment's are getting connected to the network to the SCADA system, through fiber optic communication network. Here is the OPTCL sample site of SCADA architecture. Shown here is the geographical view of the electrical network. With this, we come to the end of this topic. Thank you.
