The Schneider EM6400 supports Modbus and you can read the values into Evok or Mervis.
The L&T ER300P has RS485, but with some custom L&T protocol. You cannot easily read the data into Evok or Mervis.
Typically, the best way is to use Modbus devices. Trying to implement any other protocol would be quite time consuming and requires vast knowledge.
If I want to connect 7" display via ribbon cable by slot on PI 3B, not by pins on GPIO, is there any option how to use display in same time with UniPi? Display needs to be connected to 5V, GND and SDA, SCL pin (I2C). What I see in pictures, GPIO is used to connection UniPI so I think that display can be connected to UniPI. I hope that it is possible.
I find it!
Modbus data order: 1234.
In C program header:
typedef unsigned long DWORD;
typedef unsigned short WORD;
and in the code:
union u_DWORD_TO_FLOAT AI01;
AI01.i = (mb_mapping->tab_registers << 16) + mb_mapping->tab_registers;
float value = AI01.f;
Hope this help someone !
@Sacirovic Yes, the lib for Nodered supports both Modbus TCP (for communication with Neuron IOs) and Modbus RTU for communication with external modbus devices connected to RS485. We do not have any example for NodeRed but there are some nice youtube videos from the guy that wrote the library...
To get it working you will need a Raspbian lite and this: https://github.com/UniPiTechnology/neuron_tcp_modbus_overlay After installation this will provide the TCP Modbus server and the RS485 available at /dev/extcomm/0/0
@Wim-Stockman I will take a look at it during the next week. Thanks for the tip.
I did not check the code much but there should be some time buffer while decoding the correct input. The messages does not always come at the same time, there might be a tens of ms gap between each and you shoudl tie those together...
According to the manual: https://files.unipi.technology/index.php/s/zTmrEbQEvifNd6W?path=%2FProducts%2FNeuron%2FDocumentation#pdfviewer
chapter 2.2.1 LED diodedescription
and later MWD description. It means you do not communicate with the devices. Which is also notable that there is no output when you run the server by hand.
@rmoore I started off figuring out the GPIO pins on the bare Raspberry Pi, and once you get your head around that, moving to the Unipi is the next logical step. I did'nt use this article, but it explains just about all that you need.
The Evok "platform" can be used as well, and I use it via the restful calls for setting some of the relays.
If you've not got a Pi already, get a Pi and try the small tutorial above. After that it's straight forward enough.