KROHNE MFC 300 Modbus - Manual (Page 9)

MODBUS PROTOCOL
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MFC 300
www.krohne.com 11/2009 - 4000744801 - AD Modbus MFC 300 R01 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 Tuesday, November 24, 2009 1:48 PM