GE Multilin F650 - B.4.6.1 Event Structure

APPENDIX B: MODBUS PROTOCOL B.4 MODBUS DATA
GEK-106310-AF F650 DIGITAL BAY CONTROLLER B-13
The carry bit indicates whether the F650 has been started, since when the relay starts, whether due to lack of power
supply or a configuration change, the carry bit is set to 0. When events are generated, the event number is increased up to
a maximum value of 0x1FFF; in the next event the number is 0x1000, thus the carry bit is always 1, until the F650 is
restarted. This is shown in the following figure:
B.4.6.1 Event structure
Each event has 14 bytes, with the following format:
- Short (2 bytes): event number (0 - 2^12 + carry bit)
- Short (2 bytes): event bit number (from 0 to 191).
- Short (2 bytes): the 0 bit indicates the event value (0 or 1) and the 15 bit indicates whether this is a
valid event (all events are initially set to 0)
- Double unsigned (8 bytes): milliseconds from 1 January 2000
The 0xFCFF address is useful when reading all the available events in the F650, as is 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, is contained in one address, as shown on the table
below:
For example, the events buffer could contain the following information:
105 registers: 15 events * 7 registers.
NOTE: In this example the 0x03FF address has event number 7677 because 7676 was the last event number used.
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