Functioning in slave mode
This mode of functioning will be used when you wish, for example, to send back on the network LoRa the data coming from an existing ModBus network.
The master of the ModBus network writes the preferred values in the table of the board.
The table accepts a maximum of 512 words of 16 bits.
All or part of the table may be the subject of a LoRa frame generation.
The frame contains a maximum of 20 words of 16 bits.
Ewattchcloud compatibility
The data can be displayed directly on the Ewattchcloud platform. To do this, the modbus table must respect a format.
An online tool is available here. It makes it possible to obtain the modbus table model to follow according to the necessary data.
Physical configurations
- Switches 2 and 3 must be in “OFF” mode (low position) so as to not setup the Pull Up and Pull Down
- Switch 1 must be in “ON” mode (high position) if the board is the last slave of the bus. In the contrasting case, switch 1 must be in “OFF” mode (low position).
Software configuration for the writing in the table
On the Configurator, it is necessary to:
- Allocate an address to the board
- Configure the zone(s) of the table authorized in read and/or write (IN, OUT and IN-OUT)
- Configure the LoRa frame generation.
Requests accepted:
In slave mode, the following requests are accepted:
- WriteMultipleRegisters : 0x10
- ReadDiviceIdentification : 0x2B
- ReadHoldingRegisters : 0x03
- ReadInputRegister : 0x04
- ReadExceptionStatus : 0x07
- ReadDiagnostic : 0x08