RainWise PVMET-330 User manual

PVMET-330
User’s Guide
03/27/18
Rev. 2

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Copyright © 2018 by RainWise, Inc.
All rights reserved. No part of this work may be reproduced in any form except by
written permission of the publisher. All rights of translation are reserved.
PVMET-330™is a trademark of RainWise, Inc.

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INTRODUCTION............................................................................................................. 4
INSTALLING THE WEATHER STATION................................................................. 4
SITE REQUIREMENTS AND CONSIDERATIONS ................................................................... 4
INSTALLATION ................................................................................................................. 5
Weather Station........................................................................................................... 5
Anemometer ................................................................................................................ 5
WIRING............................................................................................................................ 5
Connecting RS-485 ..................................................................................................... 5
Connecting the Power Supply..................................................................................... 6
MODBUS RTU............................................................................................................... 6
COMMUNICATIONS........................................................................................................... 6
SCALING .......................................................................................................................... 6
UNSUPPORTED FIELDS...................................................................................................... 7
POWER MANAGEMENT............................................................................................. 7
MODBUS MAP.............................................................................................................. 8
CHANGING THE MODBUS DEVICE ADDRESS .................................................................... 9
CHANGING THE BAUD RATE ............................................................................................ 9
MINIMUM SYSTEM REQUIREMENTS................................................................... 10
RS-485....................................................................................................................... 10
Software .................................................................................................................... 10
Sensor Assembly:...................................................................................................... 11
Enclosure:................................................................................................................. 11
Pyranometer Sensor: ................................................................................................ 11
Ambient Air Temperature Sensor:............................................................................ 11
Electronics:............................................................................................................... 11
Physical: ................................................................................................................... 11
HARDWARE SPECIFICATIONS ............................................................................... 12
OPERATING ENVIRONMENT: .......................................................................................... 12
AMBIENT AIR TEMPERATURE SENSOR:.......................................................................... 12
RELATIVE HUMIDITY:.................................................................................................... 12
BAROMETRIC PRESSURE:............................................................................................... 12
ANEMOMETER (REED SWITCH)...................................................................................... 12
WIND DIRECTION:.......................................................................................................... 12
WIND SPEED:................................................................................................................. 12
RAINWISE LIQUID PRECIPITATION:................................................................................ 12
APOGEE PYRANOMETER SENSOR:.................................................................................. 13
RAINWISE B.O.M TEMPERATURE: ................................................................................ 13
CONTACT INFORMATION........................................................................................ 14
WARRANTY................................................................................................................... 14

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Introduction
The PVmet-330 weather station is a compact and economical solution for third-party
agricultural weather monitoring. It measures ambient air temperature, relative humidity,
barometric pressure, wind speed and direction and is capable of measuring rainfall, soil
or other peripheral temperature and global irradiance. The PVmet-330 uses a 2-wire half
duplex RS-485 serial port for Modbus RTU communication with a host.
Installing the Weather Station
It is suggested that the system be operated at ground level to make sure that all
components are working properly prior to installation.
If any of the components are damaged or malfunctioning upon receipt, RainWise should
be contacted.
Site Requirements and Considerations
Ambient air temperature, global irradiance, and wind speed and direction can be affected
by obstructions and local topography. Each site is different and presents challenges in its
own unique way. Any object, in excess of 10° above the horizontal plane, must not block
the global irradiance sensor. The PVMET-330 sensor assembly, which contains the
ambient air temperature and wind speed and direction sensor, should be no closer than 10
times any obstruction’s height and should be placed away from any dark, heat-absorbing
surface.
When roof-mounting the sensor assembly, the unit should be mounted toward an edge of
the roof preferably on the prevailing wind side of the building and should be at least 2-1/2
feet above the roofline. Avoid locating the station near any heat sources such as chimneys
or vents.

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Installation
Weather Station
Mount the support mast securely to a support structure. This may be done by using the
Mono-Mount, which is sold as an accessory to the PVMET-330. The mast may also be
attached to a support structure using U-Bolts. Do not tighten the support structure to the
PVMET-330 unit, as directional orientation will be required.
Rotate the assembled unit until the electronics enclosure faces TRUE SOUTH or TRUE
NORTH if you are in the northern or southern hemisphere, respectively. Secure the
support mast to the assembly. Rotation is prevented by lining up the two holes in each
mast. At this point the entire unit should be secured to the support structure.
It is crucial that the device be oriented as precisely as possible. The wind direction
measurement is directly related to this positioning.
Anemometer
The anemometer is directly attached to the top of the sensor assembly. For correct wind
direction operation, the PVmet-330 must be oriented correctly.
By default the PVmet-330 is configured for operation in the Northern hemisphere. This
only requires that the irradiance sensor faces due South. If the PVmet-330 is going to be
used in the Southern hemisphere it must be mounted with the irradiance sensor facing
North. In addition, the hemisphere jumper inside the PVmet-330 must be changed from
Northern to Southern as shown in the image be in the wiring section.
Wiring
To enter the enclosure with a cable, the front cover must first be removed. Remove the
four Philips head screws from the back of the enclosure. Once the lid is removed, the
circuit board is exposed. The inside of the enclosure will appear as below.
Connecting RS-485
The PVMET-330 is supplied with a half duplex RS-485 serial port.
Wiring connections are made using the 4-pin screw terminal inside of the PVMET-330
electronics enclosure. Cable is not supplied with the unit. The RS-485 lines can be
terminated with a 120 ohm resistor. This can be enabled by moving the termination jumper,
located inside the unit, to the “ON” position. This requires removing the enclosure cover.
To do this, remove the 4 screws on the bottom side of the unit.

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RS-485 Terminals
A (-): Negative RS-485
B (+): Positive RS-485
GND: Signal/Power Ground
+VDC: External 10-30VDC Supply
RS-485 is rated to 4,000 feet (1,200 m) at 90 kbps. The RS-485 port on the PVMET-330
is surge protected but not isolated.
Connecting the Power Supply
The weather station can either be powered from its own battery and solar panel or from
an external power source (depending on model). For systems running with external
power, a cable connection must be made between the RS-485 interface board and the
motherboard. A cable is provided and should already be connected to J2 on the RS-485
board. To switch to external power disconnect the solar panel cable and connect the
power cable in its place. The system will then be powered via the solar panel input
connector. These connections will already be made if the system is ordered without the
solar power option.
The power supply input is nominally rated for 24VDC but can accept a voltage in the
range of 10 to 30VDC. The inputs are reverse polarity, surge, overvoltage and over
current protected. The power supply is not isolated.
When replacing the cover, make sure that all installed cables are pinched by the black
foam on the bottom of the enclosure. This will enable a weather tight seal.
MODBUS RTU
These weather stations are equipped with a RS-485 communications port that supports a
subset of Modbus RTU commands. Two board rates are supported 9600 and 19,200.
Only 4X Holding registers are supported. The register map that follows describes each
register. These stations are read only.
COMMUNICATIONS
Baud: Switch 5 selects the baud rate. ON=19200, OFF=9600 (default).
Data bits: 8
Parity: None
Stop Bits: 1
Maximum Poll Rate: 5 Hz (Extended periods of rapid polling will drain the battery)
SCALING
Parameters are reported as integers. In order to maintain resolution some values are
scaled up. The scale factor shown indicate how the value should be scaled. “-1” indicates
that the value should be multiplied by 10^-1 or simply divided by 10. Rainfall is an
exception; this parameter reports the number of tips of the tipping bucket rain gauge.
Typically, the gauge is calibrated to 0.254mm (0.01”) per tip. This counter resets on a
reboot and will roll over at 65536 counts.

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UNSUPPORTED FIELDS
The register map reserves registers for all combinations of sensors supported by the
Rainwise stations. Not all will be available on any one system. Sensors/fields that are not
supported will contain the value 0x8000. Some fields require the purchase of additional
sensors. The values reported by fields that don’t have valid sensors installed should be
ignored.
POWER MANAGEMENT
The weather station will enter a low power mode when the RS-485 bus is quiet. The
station will wake on any activity and will remain awake drawing full power for 3 seconds
after the last activity on the bus. When using the weather station with its own solar power
the bus should remain inactive for the majority of the time. Suggested polling rates are
between 1 and 5 minutes. The battery voltage can be monitored to assess the station
health. Readings below 6 volts indicate a low battery. 5.8 volts is considered critical.
If the station is supplied with auxiliary power the above is not applicable and the station
can be polled as often as desired.

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MODBUS MAP
Holding
Register
Item
Type
Units
Scale
Factor
Contents
0
Manufacturer
uint16
N/A
"RW" (0x5257)
1
Model
uint16
N/A
"S0"=MK-III,
"S1"=AgroMet, "S2"=
PVmet
2
Version
uint16
N/A
0x0170, "01" Map Version,
"70" Firmware Version
3
Air Temperature
int16
Degrees
C
-1
Measured
4
Humidity
int16
%
1
Measured
5
Pressure
int16
hPa
-1
Measured
6
Wind Speed
int16
m/s
-1
Measured
7
Wind Direction
int16
Degrees
1
Measured
8
Wind Speed 5min
Avg
int16
m/s
-1
Measured
9
Wind Direction 5
min Avg
int16
Degrees
1
Measured
10
Wind Gust (5
min)
int16
m/s
-1
Measured
11
Wind Gust
Direction
int16
Degrees
1
Measured
12
Rainfall
int16
Counter
1
Measured
13
B.O.M
Temperature 1
int16
Degrees
C
-1
Measured
14
B.O.M
Temperature 2
int16
Degrees
C
-1
Measured
15
-
-
-
-
-
16
-
-
-
-
-
17
-
-
-
-
-
18
Solar Irradiance -
Global
int16
W/m2
1
Measured
19
Solar Irradiance –
P.O.A
int16
W/m2
1
Measured
20
-
-
-
-
-
21
-
-
-
-
-
22
Battery Voltage
int16
Volts
-2
Measured

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Changing the Modbus Device Address
The Modbus device can be changed using the dipswitches 1 & 2 with the default position
set to device address 60.
Modbus Address
Switch 1
Switch 2
60
0
0
61
1
0
62
0
1
63
1
1
Changing the Baud Rate
The baud rate can be set to either 9600 or 19200. The default baud rate is 9600. Changing
dipswitch 5 to the ON position will change the baud rate to 19200.

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Minimum System Requirements
The PVMET-330 is equipped with an RS-485 serial port.
RS-485
Baud rate: 9600/19,200 bps
Parity: None
Data bits: 8
Stop bits: 1
Flow Control: None
Interface mode: 2-Wire Half Duplex
Software
The PVMET-330 is designed to work with an RS-485 compliant host. A terminal emulator
program is required to change settings.