Honeywell UDC2500 manual Reference Type Definitions, File Number, Register Address

Modbus RTU Function Codes

Reference Type Definitions

The Reference Type definition is always 06.

See examples in Subsection 9.3.1

File Number

The file number word contains the register number from the register address structure tables on page 3. Although the register address structure tables indicate up to 13 data registers are available for access, only register address 3 is currently supported.

Register Address

The register address word represents the tag ID number for the parameter(s) being accessed. The register address word is made up of two bytes—the MSB = 00 always. The LSB contains the tag ID number. The tag ID numbers represent the parameter’s register address(es). See Section 3 for the tag ID numbers.

Table 9-3 Register Address Format for Function Code 20

Register	Register	Format
Address(es)	Address(es)
(Decimal)	(Hex)
001 to 125	0001 to 007D	analog formatted data
		(2 registers – IEEE 32-bit floating point)
128 to 255	0080 to 00FF	integer formatted data
		(1 register – 16-bit integer)

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