Function Code 21 (15H) - Write Configuration Reference Data - Honeywell UDC2800 Product Manual

Chapter 11 - Modbus RTU Function Codes
Where:
02 = Address
14 = Function Code 20 (14 Hex)
0E = Byte Count
06 = Reference Type (IEEE Floating Point)
00,03 = File Number (Access Data Value)
00,27 = Register Address (Standard Access LSP #1 - ID Tag 39)
00,02 = Register Count to read (Floating Point Data)
06 = Reference Type (IEEE Floating Point)
00,03 = File Number (Access Data Value)
00,35 = Register Address (Standard Access LSP #2 - ID Tag 53)
00,02 = Register Count to read (Floating Point Data)
(CRC16)
This is the response to the above request.
Response Message
02 14 0C 05 06 43 C8 00 00 05 06 44 60 00 00 (CRC16)
Where:
02 = Address
14 = Function Code 20 (14 Hex)
0C = Byte Count
05 = Data Byte Count (Sub Message Length)
06 = Reference Type (IEEE Floating Point)
43 C8 00 00 = 400.0 (Value of Local Setpoint #1)
05 = Data Byte Count (Sub Message Length)
06 = Reference Type (IEEE Floating Point)
44 60 00 00 = 896.0 (Value of Local Setpoint #2)
(CRC16)
Function Code 21 (15h) - Write Configuration
Reference Data
Introduction
Function Code 21 (15 Hex) is used in this instrument to allow writes
of integer and floating point values to the configuration database
and override values.
The configuration database of this instrument is located in EEROM.
The override values are stored in RAM.
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