GE EPM 6000 Multi-function Power Metering System DNP Implementation, Data Link Layer

Page 83

CHAPTER 5: COMMUNICATIONS

5.3DNP Implementation

5.3.1 Overview

The EPM 6000 meter is capable of using RS485 as the physical layer. This is accomplished by connecting a PC to the meter with the RS485 connection on the back face.

RS485 provides multi-drop network communication capabilities. Multiple meters may be placed on the same bus, allowing for a master device to communicate with any of the other devices. Appropriate network configuration and termination should be evaluated for each installation to insure optimal performance.

The EPM 6000 communicates in DNP 3.0 using the following communications settings: 8 data bits, no parity, and 1 stop bit. The EPM 6000 can be programmed to use several standard baud rates, including: 9600, 19200, 38400, and 57600 bps.

5.3.2Data Link Layer

The Data Link Layer as implemented on the EPM 6000 is subject to the following considerations.

The control byte contains several bits and a function code. Communications directed to the meter should be primary master messages (DIR = 1, PRM = 1). Responses will be primary non-master messages (DIR = 0, PRM = 1). Acknowledgment will be secondary non- master messages (DIR = 0, PRM = 0).

The EPM 6000 supports all of function codes for DNP 3.0:

•Reset of Data Link (function 0): Before confirmed communication with a master device, the data link layer must be reset. This is necessary after a meter has been restarted, either by applying power or reprogramming the meter. The meter must receive a RESET command before confirmed communication may take place. Unconfirmed communication is always possible and does not require a RESET command.

•User Data (function 3): After receiving a request for USER DATA, the meter will generate a data link CONFIRMATION, signaling the reception of that request, before the actual request is processed. If a response is required, it will also be sent as

UNCONFIRMED USER DATA.

•Unconfirmed User Data (function 4): After receiving a request for UNCONFIRMED USER DATA, a response will be sent as UNCONFIRMED USER DATA if required.

DNP 3.0 allows for addresses from 0 to 65534 (0000h to FFFEh) for individual device identification, with the address 65535 (FFFFh) defined as an all stations address. Addresses are programmable from 0 to 247 (0000h to 00F7h), and recognize address 65535 (FFFFh) as the all stations address.

5.3.3Transport Layer

Multiple-frame messages are not allowed for the EPM 6000. Each transport header should indicate it is both the first frame (FIR = 1) and the final frame (FIN = 1)

EPM 6000 MULTI-FUNCTION POWER METERING SYSTEM – USER GUIDE

5–13

Page 82 Page 84
Image 83
Page 82 Page 84
Contents Chapter Page Table of Contents Using the Meter Miscellaneous TOC-4 Highlights IntroductionDescription EPM 6000 Highlights Utility Peak Demand FeaturesUniversal Voltage Inputs Current InputsEPM 6000 Measured Values Measured ValuesEPM 6000 Order Codes OrderingOrder Codes Metering SpecificationsInputs/Outputs Mechanical Parameters EnvironmentalCommunications Approvals Type TestingThree-Phase Power Measurement Wye Connection Three-Phase System ConfigurationsVcn Common Phase Voltages on Wye ServicesDelta Connection Three-Phase Delta Winding RelationshipThree-Phase, Four-Wire Delta Phasors Blondells Theorem and Three-Phase MeasurementPhase B Phase C Node n Phase a Electrical Background Energy Power, Energy, and DemandPower Power Use Over Time Demand Power and Energy Relationship Over TimeEnergy Use and Demand Intervals Real, Reactive, and Apparent Power Reactive Energy and Power FactorApparent power Power FactorHarmonics of a Non-Sinusoidal Waveform Harmonic DistortionVoltage and Current Monitoring Inductive and Capacitive ImpedanceWaveform Capture Typical Power Quality Problems Power QualityElectrical Background Dimensions Mechanical InstallationAnsi and DIN Mounting Panel Cutouts Ansi Installation StepsAnsi Mounting Procedure DIN Installation StepsDIN Mounting Procedure Installation Considerations Electrical InstallationCT Leads Pass-Through No Meter Termination CT Leads Terminated to MeterQuick Connect Crimp CT Terminations Voltage and Power Supply ConnectionsVoltage Connection Ground ConnectionsWiring Diagrams 4-Wire Wye with no PTs and 3 CTs, 3 Element 2 Wye, 4-Wire with no PTs and 3 CTs, 3 Element10 4-Wire Wye with no PTs and 3 CTs, 2.5 Element 3 Wye, 4-Wire with no PTs and 3 CTs, 2.5 Element11 4-Wire Wye with 3 PTs and 3 CTs, 3 Element 4 Wye, 4-Wire with 3 PTs and 3 CTs, 3 Element12 4-Wire Wye with 2 PTs and 3 CTs, 2.5 Element 5 Wye, 4-Wire with 2 PTs and 3 CTs, 2.5 Element13 3-Wire Delta with no PTs and 2 CTs Delta, 3-Wire with no PTs and 2 CTs14 3-Wire Delta with 2 PTs and 2 CTs Delta, 3-Wire with 2 PTs and 2 CTsCurrent-Only Measurement Three-Phase Current-Only Measurement Dual-Phase Current-Only Measurement Single-Phase 3 RS485 COM2 Port Communications SetupIrDA COM1 Port 16 RS485 Communications Installation Faceplate Elements Front Panel InterfaceFaceplate Buttons Using the Meter% of Load Bar Segments Percentage of Load BarEPM 6000 Accuracy Test Constants Watt-Hour Accuracy Testing VerificationStart Up Configuring the Meter via the Front PanelOverview Main Menu Reset Mode and Password EntryUsing the Meter Using the Meter Configuring the Scroll Feature Changing Settings in Configuration ModeProgramming the Configuration Mode Screens Configuring the CT Setting Value for amps is a product of the Ct-nand the Ct-Svalues Configuring the PT SettingConfiguring the Connection Setting Configuring the Communication Port Setting Address Using the Meter Operating Mode Parameter Readings Operating ModeUsing the Meter Memory Map Modbus CommunicationsMemory Map Description HEX Range Units or Comments THD Block7 Description 1 Format Range 7532 PT denominator Secondary Readings Section Modbus Memory Map NotesCommunications Modbus Memory Map Data Formats DNP Point Mapping Sheet 1 DNP Point MappingDNP Point Maps DNP Point Mapping Sheet 2 DNP Point Map Notes Transport Layer DNP ImplementationData Link Layer Following function codes are implemented on the EPM Application LayerControl Relay Output Object 12, Variation DNP Objects and VariationsBinary Output Status Object 10, Variation 5 16-Bit Analog Input Without Flag Object 30, Variation 4 32-Bit Binary Counter Without Flag Object 20, VariationInternal Indications Object 80, Variation Class 0 Data Object 60, VariationCommunications Introduction Navigation MapsMain Menu Navigation Main Menu ScreensOperating Mode Navigation Operating Mode ScreensReset Mode Navigation Reset Mode ScreensConfiguration Mode Screens Changes to the Manual Revision HistoryRelease Dates Major Updates for 1601-0215-A2 GE Multilin Warranty WarrantyIndex Irda Power Supply Wiring
Top Page Image Contents