2 HARDWARE ARCHITECTUREThe main components comprising an General Electric Sampled Values device are as follows:● The housing, consisting of a front panel and connections at the rear● The Main processor module consisting of the main CPU (Central Processing Unit), memory and an interfaceto the front panel HMI (Human Machine Interface)● A selection of plug-in boards and modules with presentation at the rear for the sampled values inputs,power supply, communication functions, digital I/O and time synchronisation connectivityAll boards and modules are connected by a parallel data and address bus, which allows the processor module tosend and receive information to and from the other modules as required. There is also a separate serial data busfor conveying sampled data from the input module to the CPU. These parallel and serial databuses are shown as asingle interconnection module in the following figure, which shows typical modules and the flow of data betweenthem.CommunicationsSample Value InputsI/OInterconnectionOutput relay boardsOpto-input boardsIEC 61850-9-2LEinput boardRS485 modulesEthernet modulesKeypadLCDLEDsFront portWatchdog modulePSU moduleWatchdogcontacts+ LEDAuxiliarySupplyIRIG-B moduleProcessor moduleFront panel HMI Output relay contactsDigital inputsSampled ValuesRS485 communicationTime synchronisationEthernet communicationV00280Note: Not all modules are applicable to all productsMemoryFlash memory for settingsBattery-backed SRAMfor recordsFigure 4: Hardware architectureChapter 3 - Hardware Design P446SV32 P446SV-TM-EN-1
