Appendix A. Modbus reference
A.1 Default communication settings
Table 52 Default Modbus serial communication settings
Property
Description/value
Serial bit rate
19200
Parity
None
Number of data bits
8
Number of stop bits
2
Flow control
None
Modbus device address
240
You can use up to ten probes on the same RS-485 line. You must configure each probe on the
line to have a different Modbus address.
A.2 Function codes
Table 53 Modbus function codes
Function code
(decimal)
Function code
(hexadecimal)
Name
Notes
03
03
hex
Read Holding
Registers
Class 0
16
10
hex
Write Multiple
Registers
Class 0
43 / 14
2B
hex
/ 0E
hex
Read Device
Identification
A.3 Data encoding
In the data registers, the numeric values are available in one or two formats with separate
register addresses: 32-bit IEEE floating point format and/or 16-bit signed integer format.
Appendix A – Modbus reference
77
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