With the this python3 class it is very easy to communicate with the ORNO OR-WE-514, 516, 517 or EASTRON SDM72DV2 meter via RS-485 and ModBus RTU protocol. The intention was to make it very easy. Basically you need the class init with defaults and get going. The defaults should be sufficient to communicate with the device. If you're going to use MQTT a view parameters for authentication and connection have to be set and that's it. See Samples below how to do this.
Together with iobroker or similar software you can display the datapoints:
I used a RS-485 modul and build an easy RS-485 hat to my Raspberry Pi 1.
Important note: connect Pi Pin TX to Module TX and Pi RX to Module RX (that might change in these modules later as it is confusing) Connect Hat B- to OR-WE-514 Pin 25 Connect Hat A+ to OR-WE-514 Pin 23 Ground is not needed Do not forget to connect one of the two Neutral wires to your grid neutral, otherwise it will not work.
Required packages
Install the required packages if not already installed:
pip3 install minimalmodbus
pip3 install pyserial
pip3 install random
pip3 install paho-mqtt
instrument = orno.orno(port, slave_id=1, useMQTT=False, log=True, logFile="", type=orno.WE514)
port Serial Device like COM4 or /dev/ttyUSB0
slave_id The ID of the Modbus Device to communicate to
useMQTT True or False, if True it is necessary to set MQTT communication parameters
mqtt_broker IP address or hostname of MQTT server
mqtt_port the port of the MQTT broker
mqtt_topic the main topic where the ORNO objects L1_volage etc being published
mqtt_username the username for MQTT broker authentication
mqtt_password the password for MQTT broker authentication
log True/False
Writes out a logfile in current execution folder. Setting degub=True makes it more verbose.
logFile Specify a custom logFile. The class adds a timestamp between end of
filename and extension like mylog-YYYYmmdd.mextension
type the type of the ORNO device, WE514 (single phase) or WE517 (3 phase)
current supported values are:
WE514
WE516
WE517
Other parameters
debug True/False, for debug output
polling_interval number in seconds between each query of the target device
value = instrument.query(register=0, decimals=2)
This method will gather L1 Voltage, L1 Current, L1 Power, L1 Active Power, L1 Reactive Power, L1 Apparent Power,
L1 PowerFactor, L1 Frequency and Total Power.
The communication is done one time.
To query single register use a known value for register and its decimals or use predefined register variables:
orno.L1_Frequency
orno.L1_Voltage
orno.L1_Current
orno.L1_Power
orno.L1_PF
orno.L1_ActivePower
orno.L1_ReactivePower
orno.L1_ApparentPower
orno.TotalPower
Sample
TotalPower = instrument.query(orno.TotalPower,3)
insrument.read_float(address,count)
This method will read float values from the slave. Count is the number of floats or width given on documentation.
Usually it is two.
instrument.print()
The method will output L1 Voltage, L1 Current, L1 Power, L1 PowerFactor, L1 Frequence.
The method instrument.query() must be executed before.
instrument.doLoop(count=0,initite=True)
Without any given parameters the method will do a query every polling_interval seconds initinite.
If MQTT is used the gathered information is sent to the MQTT broker.
count (int) set the number of queries if set greater than 0, otherwise infinte query.
infinite (bool) True/False - do infinite query or not
instrument.mqtt_enable()
Connects to the MQTT broker
instrument.mqtt_publish()
Publishes the last retrieved data from instrument.query() to the MQTT broker.
Sample hardware (Raspberry Pi, RS-485 Module, Wiring, Connection)
Sample infinite loop and sending to MQTT Broker
import orno
instrument=orno.orno('/dev/ttyAMA0',useMQTT=True)
instrument.mqtt_broker = 'broker-hostname'
instrument.mqtt_port = 1886
instrument.mqtt_username = 'user'
instrument.mqtt_password = 'password'
instrument.mqtt_topic = 'SmartMeter/ORNO/WE-514'
instrument.debug = False
instrument.polling_interval = 10
while True:
try:
instrument.doLoop()
except:
instrument.mqtt_enable()
Sample query with count (100 times every 10 seconds) and sending to MQTT Broker
import orno
instrument=orno.orno('/dev/ttyAMA0',useMQTT=True)
instrument.mqtt_broker = 'broker-hostname'
instrument.mqtt_port = 1886
instrument.mqtt_username = 'user'
instrument.mqtt_password = 'password'
instrument.mqtt_topic = 'SmartMeter/ORNO/WE-514'
instrument.debug = False
instrument.polling_interval = 10
instrument.doLoop(count=100)
Sample to check connection and print results
import orno
instrument=orno.orno('/dev/ttyUSB0', slave_id=10, useMQTT=False)
instrument.query()
instrument.print()
Result
L1 Voltage 229.37 V
L1 Frequency 50.03 Hz
L1 Current 0.030 A
L1 Power 6.881 W
L1 Power Factor 0.125
>>>
Sample to query custom registers
import orno
instrument=orno.orno('/dev/ttyAMA0')
Voltage = instrument.query(orno.L1_Voltage,2)
Power = instrument.query(orno.L1_Power,3)
APower = instrument.query(orno.L1_ActivePower,3)
RPower = instrument.query(orno.L1_ReactivePower,3)
ApPower = instrument.query(orno.L1_ApparentPower,3)
SumPower= instrument.query(orno.TotalPower,3)
print(f"L1 Voltage : {Voltage} V")
print(f"L1 Power : {Power} W")
print(f"L1 Active Power : {APower} kW")
print(f"L1 Reactive Power: {RPower} kvar")
print(f"L1 Apparent Power: {ApPower} kva")
print(f"Total Power : {SumPower} kWh")
Sample to scan for registers on a device to discover values to use
import orno
import time as t
from datetime import datetime
import sys
if len(sys.argv) == 1:
print(f"Usage: {sys.argv[0]} StartAddress EndAddress\nusing default address range 0x0000 to 0x0360\n")
if len(sys.argv) < 2:
addr = int("0x0000",16)
end = int("0x0360",16)
else:
addr = int(sys.argv[1],16)
end = int(sys.argv[2],16)
instrument=orno.orno('/dev/ttyUSB0',type=orno.WE517)
print(f"Scanning SLAVE ID 1: from address {addr} to address {end}")
while addr <= end:
try:
time = datetime.now().strftime("%d/%m/%Y %H:%M:%S")
print(f"{time} -- Address 0x{addr:04x}: {instrument.query(addr,2)}")
except Exception as ex:
#print(f"Addr {addr}: error")
err = ex
t.sleep(0.01)
addr = addr + 1
Author: Marc-Oliver Blumenauer marc@l3c.de