using a SMP3 pyranometer

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Using a SMP3 pyranometer to monitor infrared radiation

The Kipp and Zonen SMP3-V measures the infrared radiation (from 300 to 3000 nm). It is a full modbus device.

connection to a computer using a MOXA uport 1150

On a window desktop, go to the device manager and check that the Moxa works in RS485(2W)

The SMP comes with a 8-wire cable :

• 1 - red : Not used
• 2 - blue : MODBUS GND
• 3 - green : analogue out
• 4 - yellow : MODBUS B+
• 5 - grey - MODBUS A-
• 6 - brown : analogue ground
• 7 - white : VCC (12 ACDC)
• 8 - black : GROUND

Connect the SMP as follow :

Install the Kipp and Zonen Smart Explorer software, and connect to the device

configuration for connection to the Themis RS485 bus

As the Enless radio receiver is the slave number 1 on the Themis RS485 bus, we have to change the SMP3 modbus ID. We can use the following settings :

• modbus ID : 3
• baudrate : 9600
• parity : None
• stop bits : 1

Please note that that factory configuration is :

• modbus ID : 1
• baudrate : 19200
• parity : even
• stop bits : 1

To fix the configuration in the SMP :

• change mode from normal network use to single instrument use
• go to the configuration tab
• press update

Connection to the Themis RS485 bus

modbus registers

modbus_register	parameter	Name	Description
0	IO_DEVICE_TYPE	DevType	type of the sensor
1	IO_DATAMODEL_VERSION	DataSet	Version of the object data model
2	IO_OPERATIONAL_MODE	DevMode	Operational mode: normal, service, calibration and so on
3	IO_STATUS_FLAGS	Status	Device Status flags
4	IO_SCALE_FACTOR	Range	Range and scale factor sensor data (determines number of decimal places)
5	IO_SENSOR1_DATA	Sensor1	Temperature compensated radiation in W/m2 (Net radiation for SGR)
6	IO_RAW_SENSOR1_DATA	RawData1	Net radiation (sensor 1) in W/m2
7	IO_STDEV_SENSOR1	StDev1	Standard deviation IO_SENSOR1_DATA
8	IO_BODY_TEMPERATURE	BodyTemp	temperature in 0.1 °C
9	IO_EXT_POWER_SENSOR	VSupply	External power voltage