3 character data – Varec 4000 User Manual

Page 59

4000

Modbus Implementation

9.5.2

Integer Data

•

Hexadecimal representation

•

4124Decimal equivalent: 16,676

The data returned for data address 56 is 16,676 (4124 Hex). This value must be scaled using the following formula to

give it meaning.

If a variable goes out-of-bounds (outside the minimum or maximum scale points), a value equal to the maximum

Modbus integer + 1 is returned. Writing to dynamically calculated parameters has no effect on those parameters.

9.5.3

Character Data

Character data, such as software version, are returned in registers in ASCII data format. Each Modbus register

represents two ASCII characters.

The following communication example shows the character data "ATT-" read from the ATT.

•

Hexadecimal representation 41 54 54 2D

•

ASCII representation: ATT-

Host Request
Address

Function

Code

Start Reg
H

Start Reg
L

# of Reg
H

# of Reg
L

Error
Check

ATT Response
Address

Function

code

Byte

Count

Data
MSB

Data
LSB

Data
MSB

Data
LSB

Error
Check