GE Multilin G650, Manual

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GEK-113285A G650 Generator Protection & Control System B-15
APPENDIX B B.5 OUTPUT WRITING
B
B.5.2 EVENT STRUCTURE
Each event has 14 bytes, being its format:
- Short (2 bytes): event number (0 - 2^12 + carry bit)
- Short (2 bytes): events bit number (from 0 to 191).
- Short (2 bytes): the 0 bit indicates the event value (0 or 1) and the 15 bit whether it is event (to
distinguish not valid values, in case of everything was set to 0)
- Double unsigned (8 bytes): milliseconds from 1 January 2000
The 0xFCFF-address usefulness is for when it is desired to read all the available events in the G650, something that will be
done following a master start up.
WARNING!
Unlike a standard ModBus address, these addresses consist of 14 bytes each one, instead of the 2 used in
ModBus. This way, each event, which has a structure of 14 bytes, will be contained in one address, as shown on the table
below:
Imagine that the events buffer contains the following information:
105 registers: 15 events * 7 registers.
(NOTE: the 0x03FF address will have the event number 7677 because the 7676 is the last one).
a) EVENTS COLLECTION PROCESS
ALL EVENTS
There are two possibilities:
First possibility:
start in 0xFCFF address and read events 15 by 15. The frame sent to the relay is the following one:
0xFD00 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte
............
0xFDFF 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte 1byte
Event
Number 7424 7425 .......... 7675 7676 7421 7422 7423
Address 0xFD00 0xFD01 0xFDFB 0xFDFC 0xFDFD 0xFDFE 0xFDFF