Domoticz DS238-2 ZN/S ModbusTCP plugin

A Domoticz plugin to collect data from Hiking DS238-2 ZN/S power meter ModbusTCP.

Requirements

You need the DS238 to be connected over modbus over TCP. Wired or wireless. Setup that use this on this plugin is using PW21

You need also to find the address of the DS238. You can find it using the push button. Per default the address is 1.

Installation of the plugin

This guide is based on Ubuntu 20.04 LTS:

Install pip3:

sudo apt install python3-pip

Install domoticz:

curl -sSL install.domoticz.com | sudo bash

Make sure that the plugins folder exists in the domoticz folder.

Install the plugin:

cd domoticz/plugins
git clone https://github.com/xbeaudouin/domoticz-ds238-modbus-tcp.git

Go to the plugin folder and install all required addons:

cd domoticz/plugins/domoticz-ds238-modbus-tcp
sudo pip3 install -r requirements.txt

Once that is done, restart domoticz:

sudo service domoticz.sh restart

Configuration in Domoticz

Once the plugin is installed, a new hardware type will be available: DS238-2 ZN/S ModbusTCP.

To add the inverter, go to Setup -> Hardware and add the counter:

• Enter a name for the counter.
• Select DS238-2 ZN/S ModbusTCP from the type dropdown list.
• Enter the IP address of the PW21 in the IP Address field.
• Enter the port number (default: 502) of the PW21 in the Port Number field.
• Optionally turn on Debug; be aware: this will generate a lot of entries in the Domoticz log!
• Add the counter.

This should result in a lot of new devices in the Setup -> Devices menu.

Updating the plugin

Go to the plugin folder and get the new verion:

cd domoticz/plugins/domoticz-ds238-modbus-tcp
git pull

Once that is done, restart domoticz:

sudo service domoticz.sh restart

ScreenShots

Hardware page showing a configured PW21 to get data from a DS238-2 ZN/S

The devices page show all Domoticz devices that were created for it.

The voltage graphs.

Total power meter with Return energy (usefull for PV/Wind turbine generators)

Documentation about the registers used.

This is a copy of : https://gist.github.com/alphp/95e1efe916c0dd6df7156f43dd521d53

Modbus holding registers:

Register(s)	Meaning	Scale Unit	Data format	R/W
0000h-0001h	total energy	1/100 kWh	unsigned dword	R¹
0002h-0003h	reserved		unsigned dword
0004h-0005h	reserved		unsigned dword
0006h-0007h	reserved		unsigned dword
0008h-0009h	export energy	1/100 kWh	unsigned dword	R¹
000Ah-000Bh	import energy	1/100 kWh	unsigned dword	R¹
000Ch	voltage	1/10 V	unsigned word	R
000Dh	current	1/100 A	unsigned word	R
000Eh	active power	1 W	signed word	R
000Fh	reactive power	1 VAr	unsigned word	R
0010h	power factor	1/1000	unsigned word	R
0011h	frequency	1/100 Hz	unsigned word	R
0012h	reserved		unsigned word
0013h	reserved		unsigned word
0014h	reserved		unsigned word
0015h:high	station address	1-247	unsigned char	R/W
0015h:low	baud rate	1-4²	unsigned char	R/W
001Ah	relay³		unsigned word	R/W

Notes:

Note 1:

Total, export and import energy counters can erased writing 0 in total energy registers.

Note 2:

Value mapping, default 1.

Value	Baud rate
1	9600 Bd
2	4800 Bd
3	2400 Bd
4	1200 Bd

Note 3:

In DDS238-2 ZN/SR model the relay can be switched by 0x001A register.

Value	Relay
0	Off
1	On

Data formats

Data format	Lenght	Byte order
char	8 bits
word	16 bits	Big endian
dword	32 bits	Big endian

Writing registers

The meter does not understand the 'write sigle register' function code (06h), only the 'write multiple registers' function code (10h).

Credits

Some part of the code has been taken from SolarEgde Modbus TCP Plugin. Thanks ! https://github.com/addiejanssen/domoticz-solaredge-modbustcp-plugin/