Vaisala HMP110REF User Manual

Appendix A. Modbus reference
A.1 Communication settings
The following table lists the default Modbus serial settings of devices ordered with the Modbus
configuration option.
Table 38 Modbus 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
Serial delay 0
Communication mode Modbus RTU
You can use up to 32 probes on the same RS-485 line when the communication speed is
19200 bps or lower. You must configure each probe on the line to have a dierent Modbus
address.
RS-485 termination must not be used with HMP60/HMP110 series probes.
After power-up, it may take up to 2 seconds before the probe responds to any
Modbus request.
A.2 Function codes
Table 39 Supported Modbus function codes
Function code Function code (hexadecimal) Name
03 03
hex
Read Holding Registers
16 10
hex
Write Multiple Registers
Appendix A – Modbus reference
85

Vaisala HMP110REF Specifications

General

Brand	Vaisala
Model	HMP110REF
Category	Measuring Instruments
Language	English