Floating point data – Varec 4000 User Manual
Page 62

Modbus Implementation
Tank Gauge Transmitter
52
Installation and Operations Manual
9.6.4
The One 32-bit Register Format
Function code 65 (41 Hex) is used to read floating-point registers in this format. An example of a floating-point
register read is shown below with the a temperature of 100.0 degrees is being read from register 1 (0001 Hex).
9.6.5
Floating Point Data
•
Hexadecimal representation: 42 C8 00 00
•
Decimal equivalent: 100.00
Function code 66 (42 Hex) is used to write floating-point registers. An example of a floating-point register write is
shown below with the value 100.0 being written into the Advisory High Temperature Alarm Setpoint, register 12 (000C
Hex).
9.6.6
Floating Point Data
•
Hexadecimal representation: 42 C8 00 00
•
Decimal equivalent: 100.00
Floating-point registers that are defined as reserved have zero (0) as their value. A write command to a reserved
floating-point register will be ignored.
Host Request
Address
Function
Code
Start
Reg H
Start
RegL
# of
Reg H
# of
Reg L
Error
Check
01
41
00
01
00
01
XX
ATT Response
Address
Function
code
# of
Reg H
# of
Reg L
Data
MSB
Data
Data
Data
LSB
Error
Check
01
41
00
01
42
C8
00
00
XX
Host Request
Address
Function
Code
Start Reg
H
Start Reg
L
# of Reg
H
# of Reg
L
Data
MSB
01
42
00
0C
00
01
42
Data
Data
Data
LSB
Error
Check
C8
00
00
XX
ATT Response
Address
Function
code
# of Reg
H
# of Reg
L
Error
Check
01
03
02
41
XX