HD2013.3
- 17 -
V1.7
6
MODBUS-RTU PROTOCOL
By default, the instrument has MODBUS address
1
and communication parameters
19200, 8E1. The address and the communication parameters can be changed by using
the appropriate serial commands of the proprietary protocol or, alternatively, directly
with MODBUS commands by changing the value of the Holding Registers described
later.
The MODBUS-RTU protocol, if set as the operating protocol (default), is active after 10
seconds from the instrument power on.
In order to change the instrument configuration using the MODBUS-RTU protocol, the
value 1 must be written first in the
Coil
number with address 1.
Below is the list of registers.
Discrete inputs:
Address
Description
Format
0
Indication of no precipitation (0) or precipitation in progress (1).
Bit
1
Validity of the precipitation indication: 0=no, 1=yes.
Bit
2
Indication of the type of precipitation:
0=rainfall, 1=snowfall.
Bit
Input Registers:
Address
Description
Format
0
Instrument model identification.
16-bit Integer
1
Instrument hardware revision.
16-bit Integer
2,3
Instrument serial number.
(*)
16-bit Integer
4
Instrument firmware revision. The most significant byte indicates
the major revision; the less significant byte indicates the minor
revision.
16-bit Integer
5
Number of reboots that occurred.
16-bit Integer
6
Number of watchdog timeouts that occurred.
16-bit Integer
7
Power supply voltage in Volt (x10).
16-bit Integer
8
Internal board temperature (x10).
16-bit Integer
9
Number of 12-bit ADC counts, proportional to the percentage of
dry sensitive surface of the sensor.
16-bit Integer
10
Percentage of dry sensitive surface of the sensor (x10 if the reso-
lution is 0.1%).
16-bit Integer
11
Number of MODBUS communication error.
16-bit Integer
12
Ambient temperature (x10).
16-bit Integer
13
Heater temperature (x10).
16-bit Integer
14
Percentage of heating power used.
16-bit Integer
15
Indication of precipitation absent/in progress and type of precipi-
tation:
0=no precipitation
1=rainfall
2=snowfall
16-bit Integer
