Varec 4000 manual One 32-bit Register Format

Modbus Implementation Tank Gauge Transmitter

9.6.4The 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).

Host Request
Address	Function	Start	Start	# of	# of	Error
	Code	Reg H	RegL	Reg H	Reg L	Check
01	41	00	01	00	01	XX
ATT Response
Address	Function	# of	# of	Data	Data	Data	Data	Error
	code	Reg H	Reg L	MSB			LSB	Check
01	41	00	01	42	C8	00	00	XX

9.6.5Floating 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).

Host Request

Address	Function	Start Reg	Start Reg	# of Reg	# of Reg	Data
	Code	H	L	H	L	MSB
01	42	00	0C	00	01	42
			Data	Data	Data	Error
					LSB	Check
			C8	00	00	XX
ATT Response
Address	Function	# of Reg	# of Reg	Error
	code	H	L	Check
01	03	02	41	XX

9.6.6Floating 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.

52 Installation and Operations Manual