Modbus protocol, 3 addressing, 4 overview of supported functions – KROHNE IFC 300 Converter Modbus EN User Manual

Page 9

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MODBUS PROTOCOL

6

9

IFC 300

www.krohne.com

07/2010 - 4000410703 - AD Modbus IFC 300 R03 en

6.3 Addressing

In the following tables the Modbus protocol addresses / data addresses are listed.

Some systems cannot use addresses above 9999. For these systems there is the possibility to
use the listed addresses but

• for Input Registers omit the leading 3 of 3xxxx;
• for Holding Registers omit the leading 4 of 4xxxx;
• for Input Registers replace the leading 20 of 20xxx by 9xxx.

Sometimes register numbers are asked for. The register numbers

register numbers

register numbers

register numbers can be calculated by adding a

1 to the protocol address and using a prefix according to the block:

• prefix 1 for coils
• prefix 3 for Input Registers
• prefix 4 for Holding Registers

6.4 Overview of supported functions

The following table shows Modbus functions supported by RS485 interface.

Function code

Name

Access to

hex

dec

01

01

Read Single Coil

Status of calibration functions, counter

status (start/stop)

03

03

Read Holding Register

Converter configuration parameter

04

04

Read Input Register

Measurement values, status values and

calibration results

05

05

Write Single Coil

Cold start, warm start, error reset, start

calibration function, start/stop counter

08

08

Diagnostics

-

10

16

Write Multiple Register

Converter configuration parameter

.book Page 9 Friday, July 9, 2010 10:31 AM

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