Honeywell HC900 - Manual (Page 23)

Modbus Double Register Format
Unsigned/signed 32-bit Register Formats
Revision 10 HC900 Hybrid Controller Communications User Guide 15
12/07
FP L – Little Endian Format
The value 12345678 Hex will be represented as follows:
Bit 7 Bit 16
High Low High Low
REGISTER N
(High)
REGISTER N+1
(Low)
Byte 2
56 Hex
Byte 1
78 Hex
Byte 4
12 Hex
Byte 3
34 Hex
Bit 0 Bit 31 Bit 24 Bit 23 Bit 8 Bit 15