Appendix; General Information; Special Informationen About The Modbus Slave Function - mru SWG100 BIOEX User Manual

26.

APPENDIX

27. General information

The Modbus/Profibus Slave function requires the analyser firmware version V1.11.00 dated
12.07.2016 or later.
Multi byte values are transmitted in Motorola
end of each frame is transmitted in Intel
In case you need Little-Endian byte order in the master's system:
- 16bit values (occurs only in the frame): swap bytes 0<=>1
- 32bit values (occurs only in the data): swap bytes 0<=>3 and swap bytes 1<=>2
All addresses written in this document are decimal (not hexa-decimal)
All readable data are 32bit values, therefore the analyser only accepts even addresses
end even number of registers to be read.
Data types (used in table below):
U32 32 bit unsigned integer value (0...4.294.967.295)
FL 32 bit floating point value (reads -1E38, when not available)
Some values are optional (e.g. gas-cooler).

27.1. Special informationen about the Modbus Slave function

•
The analysers are able to work as modbus slave using the RS232 or RS485 port (possibly
with external RS232/RS485 adapter)
• supports RS485 interface with 2/4 wires (half/full duplex)
supports only the binary Modbus protocol (RTU)
•
supports modbus command Read Holding Register (command no 3)
•
supports modbus command Read Input Register (command no 4)
•
• the slave modbus address is user definable from 1 to 238
•
communication parameter are user definable as follows:
- 9600 baud or 19200 baud (recommended)
- odd, even or none parity
- 1 or 2 stop bits
• The maximal number of 32bit-values to be read with one single read command is
63
(126 modbus registers)
MRU GmbH, D-74172 Neckarsulm
SWG100BIO Ex. User Manual
Big-Endian
byte order (
®
-Endian
byte order (Little
®
). Only the CRC16 at the
).
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