MODBUSAppendix A — MODBUS Implementation
Varec, Inc.
155
Example of 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).
Example of Floating-point Data
• Hexadecimal representation: 42 C8 00 00
• Decimal equivalent: 100.00
Floating-point registers that are defined as reserved will respond with undocumented values.
A write command to a reserved floating-point register will be ignored.
Host Request
Address
Function
Code
Start Reg
H
Start Reg
L
# of Reg
H
# of Reg
L
Error
Check
01
41
00
01
00
01
AD C5
2920 FTT 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
78 85
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
27 6D
2920 FTT Response
Address
Function
Code
# of Reg
H
# of Reg
L
Error
Check
01
42
00
01
60 0C
Summary of Contents for 2920
Page 2: ......
Page 16: ...2920 Float Tape Transmitter 1 Introduction 6 Installation and Operations Manual...
Page 114: ...2920 Float Tape Transmitter 6 Bi Phase Mark 104 Installation and Operations Manual...
Page 120: ...2920 Float Tape Transmitter 7 MODBUS 110 Installation and Operations Manual...
Page 126: ...2920 Float Tape Transmitter 9 L J TankWay 116 Installation and Operations Manual...
Page 158: ...2920 Float Tape Transmitter 14 Ordering Information 148 Installation and Operations Manual...
Page 193: ......
