Honeywell UDC2500 - Manual (Page 198)

Modbus RTU Function Codes
184 UDC2500 Universal Digital Controller Product Manual 4/07
9.3.1 Read Configuration Examples
Example #1
The following is an example of a request to read the Gain 1 value using Function code
20.
Request Message (Read (Gain 1) = ID Tag 001)
02 14 07 06 00 03 00 01 00 02 (CRC16)
Where:
02 =
Address
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)