Honeywell UDC2800 User Manual

14 =Function Code 20 (14 hex)
07 = Byte Count
06 = Reference Type
00,03 = File Number (Access Data Value)
00,01 = Register Address (Standard Access Gain 1 - Tag ID #1)
00 02 = Register Count (Floating Point Data)
(CRC16)
This is the response to the above request.
Response Message
02 14 06 05 06 3F C0 00 00 (CRC16)
Where:
02 = Address
14 = Function Code 20 (14 Hex)
06 = Byte Count
05 = Sub Message Length
06 = Reference Type (IEEE Floating Point)
3F C0 00 00 = 1.50 (Value of Proportional Band)
(CRC16)
Example #2
The following is another example of a request and response message
using Function code 20.
Request Message (Read LSP #1 = ID Tag 39 and LSP #2 = ID Tag 53)
02 14 0E 06 00 03 00 27 00 02 (CRC16)
Where:
02 = Address
14 = Function Code 20 (14 Hex)
07 = Byte Count
06 = Reference Type (IEEE Floating Point)
00,03 = File Number (Access Data Value)
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Chapter 11 - Modbus RTU Function Codes 20&21

Honeywell UDC2800 Specifications

General

Control Modes	PID, ON/OFF, Manual
Mounting	Panel Mount
Display	Dual 4-digit LED
Input Types	Thermocouple, RTD, mA, mV, V
Output Types	Relay
Power Supply	100-240 VAC, 50/60 Hz
Communication	RS-485 Modbus RTU
Enclosure Rating	NEMA 4X