2 unsigned/signed 32-bit register formats – Honeywell HC900 User Manual
Page 21
Modbus Double Register Format
Unsigned/signed 32-bit Register Formats
Revision 10
HC900 Hybrid Controller Communications User Guide
13
12/07
3.2 Unsigned/signed 32-bit Register Formats
The formats descriptions below use the value 12345678 Hex as an example. Where the binary representation is:
Byte 4 = 12 Hex
Byte 3 = 34 Hex
Byte 2 = 56 Hex
Byte 1 = 78 Hex
Bits
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2
1
0
0 0 0 1 0 0 1 0 0 0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1 0 0 0
FP B – Big Endian Format
The value 12345678 Hex will be represented as follows:
Bit 31
Bit 0
High
Low
High
Low
REGISTER N
(High)
REGISTER N+1
(Low)
Byte 4
12 Hex
Byte 3
34 Hex
Byte 2
56 Hex
Byte 1
78 Hex