Hi, I finally got my modbus binding too work. I’m reading SDM120M energymeters. Got 12 of them, but only connected 6 of them on a USB-RS485 dongle.
I got a few problems:
- The values I’m getting are wrong, voltage should be around 230v, is giving me 1 or with other settings something very small.
- Can not use the symlink ttyRS485, only ttyUSB0 works, ttyRS485 gives permissions problems.
- Sometimes modbus hangs and I need a restart of openhab to get is to work. Are there still problems with nrjavaserial? Can I upgrade something?
Trying to get this working for a few days now … I need some help. Sorry for the long post.
Hardeware stuff:
Running Openhab 3.2 on a HP t630 thin client running Debian.
Software stuff:
###@scouthab:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 11 (bullseye)
Release: 11
Codename: bullseye
###@scouthab:~$ java -version
openjdk version "11.0.13" 2021-10-19 LTS
OpenJDK Runtime Environment Zulu11.52+13-CA (build 11.0.13+8-LTS)
OpenJDK Server VM Zulu11.52+13-CA (build 11.0.13+8-LTS, mixed mode)
openhab> bundle:list|grep Modbus
255 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: Modbus Binding
256 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: E3DC Modbus Binding
258 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: Modbus SBC Binding
275 │ Active │ 80 │ 3.2.0 │ openHAB Core :: Bundles :: Modbus Transport
openhab> log:set INFO org.openhab.binding.modbus
openhab> list -s | grep nrjavaserial
249 │ Active │ 80 │ 5.2.1 │ nrjavaserial
openhab> openhab:serial identifiers
[name: /dev/ttyUSB1, current owner: null]
[name: /dev/ttyUSB0, current owner: null]
[name: /dev/ttyS0, current owner: null]
1. Wrong values
After fixing some wiring problems, I’m able to get readings from them directly using Python.
***@scouthab:~$ python3 sdm_modbus/example-rtu.py --stopbits 1 --parity N --baud 9600 --unit 1 /dev/ttyRS485
SDM120(/dev/ttyRS485, connectionType.RTU: stopbits=1, parity=N, baud=9600, timeout=1, retries=3, unit=0x1):
Input Registers:
Voltage: 233.80V
Current: 0.03A
Power (Active): 0.00W
Power (Apparent): 0.00VA
Power (Reactive): 0.00VAr
Power Factor: 1.00
Phase Angle: 0.00°
Frequency: 50.00Hz
Imported Energy (Active): 108.94kWh
Exported Energy (Active): 0.00kWh
Imported Energy (Reactive): 9.43kVArh
Exported Energy (Reactive): 16.95kVArh
Total Demand Power (Active): 0.00W
Maximum Total Demand Power (Active): 1475.33W
Import Demand Power (Active): 0.00W
Maximum Import Demand Power (Active): 1475.33W
Export Demand Power (Active): 0.00W
Maximum Export Demand Power (Active): 0.00W
Total Demand Current: 0.00A
Maximum Total Demand Current: 6.43A
Total Energy (Active): 108.94kWh
Total Energy (Reactive): 26.39kVArh
Holding Registers:
Demand Time: 57s
Demand Period: 60s
Relay Pulse Width: 60ms
Network Parity Stop: N-1
Meter ID: 1
Baud Rate: 9600
P1 Output Mode: Export Energy (Active)
Display Scroll Timing: 0s
P1 Divisor: 0.001kWh/imp
Measurement Mode: 0
Pulse/LED Indicator Mode: Import + Export Energy (Active)
Got a modbus connection thing:
UID: modbus:serial:SDM120_1
label: SDM120_1
thingTypeUID: modbus:serial
configuration:
baud: 9600
connectMaxTries: 1
timeBetweenTransactionsMillis: 100
stopBits: "1.0"
parity: none
receiveTimeoutMillis: 1500
dataBits: 8
echo: false
encoding: rtu
flowControlIn: none
flowControlOut: none
port: /dev/ttyUSB0
connectTimeoutMillis: 10000
id: 1
enableDiscovery: false
A values read thing:
UID: modbus:poller:SDM120_1:SDM120_1_power
label: SDM120-1 Values
thingTypeUID: modbus:poller
configuration:
length: 14
start: 0
refresh: 10000
maxTries: 3
cacheMillis: 50
type: holding
bridgeUID: modbus:serial:SDM120_1
A voltage read thing:
UID: modbus:data:SDM120_1_power:SDM120-1_voltage
label: SDM120-1 Voltage
thingTypeUID: modbus:data
configuration:
readValueType: float32
readTransform: default
writeTransform: default
readStart: "0"
updateUnchangedValuesEveryMillis: 1000
writeMultipleEvenWithSingleRegisterOrCoil: false
writeMaxTries: 3
bridgeUID: modbus:poller:SDM120_1:SDM120_1_power
A current read thing:
UID: modbus:data:SDM120_1_power:SDM120-1_current
label: SDM120-1 Current
thingTypeUID: modbus:data
configuration:
readValueType: float32
readTransform: default
writeTransform: default
readStart: "6"
updateUnchangedValuesEveryMillis: 1000
writeMultipleEvenWithSingleRegisterOrCoil: false
writeMaxTries: 3
bridgeUID: modbus:poller:SDM120_1:SDM120_1_power
And a power read thing:
UID: modbus:data:SDM120_1_power:SDM120-1_power
label: SDM120-1 Power
thingTypeUID: modbus:data
configuration:
readValueType: float32
readTransform: default
writeTransform: default
readStart: "12"
updateUnchangedValuesEveryMillis: 1000
writeMultipleEvenWithSingleRegisterOrCoil: false
writeMaxTries: 3
bridgeUID: modbus:poller:SDM120_1:SDM120_1_power
This results in the following log output:
2022-01-08 20:27:24.324 [DEBUG] [t.wimpi.modbus.io.ModbusRTUTransport] - Sent: 01 03 00 00 00 0e c4 0e
2022-01-08 20:27:24.406 [DEBUG] [t.wimpi.modbus.io.ModbusRTUTransport] - Response (CRC OK): 01 03 1c 3f 80 00 00 42 70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 42 70 00 00 37 22
2022-01-08 20:27:24.407 [DEBUG] [bus.handler.ModbusPollerThingHandler] - Thing modbus:poller:SDM120_1:SDM120_1_power received response PollResult(result=AsyncModbusReadResult(request = ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3], registers = ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000)))
2022-01-08 20:27:24.410 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_voltage channels updated: {modbus:data:SDM120_1_power:SDM120-1_voltage:number=1.0}. readValueType=float32, readIndex=Optional[0], readSubIndex(or 0)=0, extractIndex=0 -> numeric value 1.0 and boolValue=true. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
2022-01-08 20:27:24.412 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_power channels updated: null. readValueType=float32, readIndex=Optional[12], readSubIndex(or 0)=0, extractIndex=12 -> numeric value 60.0 and boolValue=true. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
2022-01-08 20:27:24.413 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_current channels updated: null. readValueType=float32, readIndex=Optional[6], readSubIndex(or 0)=0, extractIndex=6 -> numeric value 0.0 and boolValue=false. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
In short:
Sent: 01 03 00 00 00 0e c4 0e
Response (CRC OK): 01 03 1c 3f 80 00 00 42 70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 42 70 00 00 37 22
extractIndex=0 -> numeric value 1.0
extractIndex=12 -> numeric value 60.0
extractIndex=6 -> numeric value 0.0
Using float32_swap instead of float32 … also gives strange results.
2022-01-08 20:34:58.454 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_voltage channels updated: {modbus:data:SDM120_1_power:SDM120-1_voltage:number=0.000000000000000000000000000000000000000022779507836064226}. readValueType=float32_swap, readIndex=Optional[0], readSubIndex(or 0)=0, extractIndex=0 -> numeric value 0.000000000000000000000000000000000000000022779507836064226 and boolValue=true. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
2022-01-08 20:34:58.455 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_power channels updated: null. readValueType=float32_swap, readIndex=Optional[12], readSubIndex(or 0)=0, extractIndex=12 -> numeric value 0.00000000000000000000000000000000000000002383328428123649 and boolValue=true. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
2022-01-08 20:34:58.456 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Thing modbus:data:SDM120_1_power:SDM120-1_current channels updated: null. readValueType=float32_swap, readIndex=Optional[6], readSubIndex(or 0)=0, extractIndex=6 -> numeric value 0.0 and boolValue=false. Registers ModbusRegisterArray(3F800000427000000000000000000000000000000000000042700000) for request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=0, length=14, maxTries=3]
In short:
same respons
extractIndex=0 -> numeric value 0.000000000000000000000000000000000000000022779507836064226
extractIndex=12 -> numeric value 0.00000000000000000000000000000000000000002383328428123649
extractIndex=6 -> numeric value 0.0
Is there a setting I have wrong?
2. Not able to use ttyRS485
I’ve seen https://www.openhab.org/docs/administration/serial.html and added all stuff there.
Modified /etc/default/openhab with the
EXTRA_JAVA_OPTS="-Dgnu.io.rxtx.SerialPorts=/dev/ttyUSBP1:/dev/ttyRS485:/dev/ttyUSB0:/dev/ttyUSB1"
User is in the needed group(s)
***@scouthab:~$ groups openhab
openhab : openhab tty dialout sudo audio bluetooth
Using Udev rules to link RS485 USB stick to /dev/ttyRS485, it’s there and it’s working with other programs.
***@scouthab:~$ ls -lhS /dev/ttyUSB0
crw-rw---- 1 root dialout 188, 0 6 jan 12:36 /dev/ttyUSB0
***@scouthab:~$ ls -lhS /dev/ttyRS485
lrwxrwxrwx 1 root root 7 6 jan 01:38 /dev/ttyRS485 -> ttyUSB0
openhab> openhab:serial identifiers
[name: /dev/ttyUSB1, current owner: null]
[name: /dev/ttyUSB0, current owner: null]
[name: /dev/ttyS0, current owner: null]
Using ttyRS485: results in the following errors:
2022-01-06 13:45:35.921 [ERROR] [ing.ModbusSlaveConnectionFactoryImpl] - re-connect reached max tries 1, throwing last error: Could not get port identifier, maybe insufficient permissions. null. Connection SerialConnection [m_SerialPort=null, m_Parameters.getPortName()=/dev/ttyRS485]. Endpoint ModbusSerialSlaveEndpoint [getPortName()=/dev/ttyRS485]
2022-01-06 13:45:35.921 [ERROR] [ing.ModbusSlaveConnectionFactoryImpl] - Error connecting connection SerialConnection [m_SerialPort=null, m_Parameters.getPortName()=/dev/ttyRS485] for endpoint ModbusSerialSlaveEndpoint [getPortName()=/dev/ttyRS485]: Could not get port identifier, maybe insufficient permissions. null
2022-01-06 13:45:35.922 [WARN ] [rt.modbus.internal.ModbusManagerImpl] - Could not connect to endpoint ModbusSerialSlaveEndpoint [getPortName()=/dev/ttyRS485] -- aborting request ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=30013, length=2, maxTries=3] [operation ID 19ad4f20-e7dc-40da-a994-c9d08b70b0f8]
2022-01-06 13:45:40.924 [WARN ] [ing.ModbusSlaveConnectionFactoryImpl] - connect try 1/1 error: Could not get port identifier, maybe insufficient permissions. null. Connection SerialConnection [m_SerialPort=null, m_Parameters.getPortName()=/dev/ttyRS485]. Endpoint ModbusSerialSlaveEndpoint [getPortName()=/dev/ttyRS485]
Some posts mention to set something via openhabian-config:
- system related (option 30)
- serial port (option 35)
However when I try to select option 35 … I’m not able to see that menu and switch back to the previous menu … maybe because I do not use a Raspberry Pi?
3. Still something with nrjavaserial?
Read that the problem was fixed in 3.1.0 and up … or was I wrong? Do I still need to update something?
openhab> bundle:list|grep Modbus
255 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: Modbus Binding
256 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: E3DC Modbus Binding
258 │ Active │ 80 │ 3.2.0 │ openHAB Add-ons :: Bundles :: Modbus SBC Binding
275 │ Active │ 80 │ 3.2.0 │ openHAB Core :: Bundles :: Modbus Transport
openhab> list -s | grep nrjavaserial
249 │ Active │ 80 │ 5.2.1 │ nrjavaserial
