BLN nobel G5, Technical Manual

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G5 Weighing Instrument
6-25
Fieldbus Data Definitions
Data from the network (Outputs in the master). 16 bytes mapped to the network in the
instrument. Most significant byte is always first in multi byte values.
Byte No of bytes Contents
00 1 Command
01 1 Number of registers to write
02 2 Start address, Read/Write
04 2 Write register 1
06 2 Write register 2
08 2 Write register 3
10 2 Write register 4
12 2 Write register 5
14 2 Write register 6
Byte 0: The command byte is used when setting the read window starting address,
writing data to the instrument and to issue various scale related commands such as
taring, zeroing etc.
Commands:
0 No action
250 (hex FA) Change read window
251 (hex FB) Write data
252 (hex FC) Clear the Program reset bit in the Instrument Status register.
Plus commands according to the manual, chapter ‘Communication – Modbus protocol
– Command register’.
Note that a new command is detected when the content of the command register is
changed. If the same command is used more than once another command e.g. 0 must
be used in between.
The response to a given command is the ‘Command acknowledge’ and the
‘Command error’ bytes that are described below in section ‘Data to the network’.
Byte 1: Used to define the number of registers to write.
Bytes 2 and 3: Define from which register number to read or write.
Bytes 4 to 15: Contains the data when writing to the instrument.