GE 750

750/760 FEEDER MANAGEMENT RELAY – COMMUNICATIONS GUIDE TOC - V
Table of Contents
1.OVERVIEW OverviewProtocols........................................................................................................................... 1 - 1
Physical Layer ................................................................................................................................... 1 - 2
2.MODBUS
PROTOCOL
Description.......................................................................................................................................... 2 - 1
Data Link Layer................................................................................................................................. 2 - 1
CRC-16 Algorithm ............................................................................................................................ 2 - 2
Message Timing................................................................................................................................ 2 - 3
3.MODBUS
FUNCTIONS
Supported Modbus Function Codes........................................................................................ 3 - 1
Function Code 01h/02h: Read Binary Status...................................................................... 3 - 2
Function Code 03h/04h: Read Actual Values / Setpoints ............................................. 3 - 2
Function Code 05h: Execute Operation................................................................................. 3 - 3
Function Code 06H: Store Single Setpoint............................................................................ 3 - 5
Function Code 10H: Store Multiple Setpoints ..................................................................... 3 - 5
Exception Responses ..................................................................................................................... 3 - 6
Clock Synchronization of Multiple Relays ............................................................................ 3 - 7
4.MODBUS MEMORY
MAP
Reading the Event Recorder ....................................................................................................... 4 - 1
Reading Trace Memory................................................................................................................. 4 - 2
Reading the Data Logger ............................................................................................................. 4 - 4
Accessing Data via the User Map............................................................................................. 4 - 4
Memory Map Organization .........................................................................................................4 - 5
Memory Map...................................................................................................................................... 4 - 6
Data Formats...................................................................................................................................4 - 46
Data Formats Notes .....................................................................................................................4 - 65
5.DNP
COMMUNICATIONS
DNP 3.0 Device Profile Document............................................................................................ 5 - 1
DNP Implementation...................................................................................................................... 5 - 3
6.DNP POINT LISTS Binary Input / Binary Input Change........................................................................................ 6 - 1
Binary / Control Relay Output.................................................................................................... 6 - 3
Analog Input / Analog Input Change ...................................................................................... 6 - 5