Modbus¶
Available in HW 3.5+
Modbus Sensor RTU (RS485)¶
Since version LK3.5+ SW 1.36 it is possible to operate up to three independent devices on one Modbus bus. The configuration, as before, consists in selecting the module and specifying its slave ID, with the difference that up to three slots can be supplemented this way.
Following modules are supported:
- SDM120
- SDM72D-M
- RDO-PRO X
- Epever Tracer
- Sofarsolar
- GTIL
- Danfos EKC 202C
Info
Note that in hardware version 3.7+, it is possible to connect 2 modules simultaneously (one from Serial Port tab and one from Modbus tab).
In versions 3.5 and 3.6, you can only select one module from the Serial Port or Modbus card.
In version 3.0 the Modbus card is not available, therefore you can select only one module from the Serial Port tab.
Readings mapping¶
To use readings from Modbus modules, outside of the Modbus tab, you need to configure the mapping of readings to the variables m1 - m30. Readings are assigned to variables separately on each slot (Configure mapping button), but the variables are shared among all slots.
Note that the m variable can only be associated with one reading and that when you change the variable assignment, its previous assignment will be removed. Additionally, the mapping does not change when the module on the slot is changed - it can show readings from the slot where the module is not selected.
The variables m1 - m30 can be used later in the HTTP client, MQTT client, OLED, VOLED. The first 4 variables m1 - m4 are also available as an option I in Power and Energy tab where they can be used as POWER readings.
Custom devices¶
You can also configure a custom device. To do this, select one of the three options marked (custom) in the Module field and then open the form with the Configure custom module button (it can be done on any slot).
In the form, enter your own name, communication data (bitrate, parity bit, stop bit, delay between register reads (in s)) and define the list of readings, giving each name, unit, divisor, register address, function code, type. After saving the device configuration, it can be selected on any of the three slots.
The configuration can be exported to a file by clicking on the Export configuration button and loaded for saving by clicking Import configuration. Sample configuration to be imported for SDM72D is available for download here.
Modbus TCP Server¶
Form for enabling Modbus TCP Server and table with information about available data.