Hello @knebb, as @ntd wrote there is no need to use the Evok (which is, basically a bridge between Modbus server and several web-service interfaces). The simplest option for direct access from a C/C++ application should be the sysfs interface. Of course, a Modbus client connected to the internally running Modbus server can be used also.

OK, now it is a bit clearer. You probably did not insert TCP port while you have been asked for it during the installation process. Default values within the file are:

upstream evok {
        server localhost:8080;
}

server {
	listen 80 default_server;
	server_name  _;

	#ssl on;
	#ssl_certificate      /etc/nginx/democert.pem;
	#ssl_certificate_key  /etc/nginx/democert.key;

	#access_log  /var/log/evok.access.log;
	access_log  off;
	root /var/www/evok;

	location / {
	    index index.html;	    
	}
	
	location /favicon.ico {
		alias /var/www/evok/favicon.ico;
	}

	location /ws {
		proxy_pass http://evok;
		proxy_set_header Host $host:$server_port;
		proxy_http_version 1.1;
		proxy_set_header Upgrade $http_upgrade;
		proxy_set_header Connection "upgrade";
		proxy_buffering off;
		proxy_cache off;
		proxy_read_timeout 180;
	}

	location /rest {
		proxy_pass http://evok;
		proxy_set_header Host      $host:$server_port;
	}
	
	location /json {
		proxy_pass http://evok;
		proxy_set_header Host      $host:$server_port;
	}
	location /bulk {
		proxy_pass http://evok;
		proxy_set_header Host	$host:$server_port;
	}
	location /rpc {
		proxy_pass http://evok;
		proxy_set_header Host	$host:$server_port;
	}
	
}

Hello @Achilleas-Kotsis ,

thank you for your detail report!

We check this and will get back. With the previous version of unipi-kernel-modules package, the issue never appears?

How did you simulate the issue in the listing above? By a loopback using the other serial?

Hello @mglowinski,

Pins RXD0 a TXD0 (GPIO14/GPIO15, pins no. 8 and 10) -> primary UART are connected to the RJ connector.

The most simple test is to install a terminal application ( e.g. minicom) and probe the UART in loopback mode.

From RasberryOS, you can manipulate the UART using the raspi-config utility.

Instruction how do disable BT or redirect it to Mini UART can be found on the link above.

Hello @mglowinski,

what OS Image and Rasberry Pi generation do you have?

You have to take into account that UART pins can be shared with Bluetooth and there are two types of UART
available (full-featured and the limited one).
More detail info about the Raspberry’s UARTs can be found here:

https://www.raspberrypi.org/documentation/configuration/uart.md

Hello @mglowinski,

there should not be any problem. I2C devices on the same bus can be accessed from multiple processes (apps or kernel modules).

Hello @mglowinski,

mapping for all RPi based units is quite simple - just a single serial port, typically /dev/ttyAMA0 is available to the user.

Hello @mglowinski,

the mentioned uart API is intended for serial lines configuration only.

To send/receive data, you can use a standard Linux file-based approach. As you have not specified PLC series used, example for AXON units serial mapping can be found here:

https://kb.unipi.technology/en:hw:01-axon:portmap

Hello @mglowinski,

unfortunately, there is no fully-generic way to access I2C devices (e.g. sensor) from Evok.

Hello @Maxiba,

the issue described occurs because the curl command sends two separate requests in fact (one for each input).

Opposite, the Python script does not have intelligence and sends exactly what you pass to it while Evok does not support this request syntax.

In your case, you can consider using JSON Bulk request to read/write more I/Os at once.

https://evok-14.api-docs.io/1.11/bulk/bulk-json-request

Hello @Jan-Toth,

you have not specified IDE/Language used. For example, in Mervis IDE you can use the following approach:
Automatic restart of the 1-Wire bus

Can you share more info about the application?

Hello @oflock,

thank you for using our products!

As the internal single-board computer has an onboard WiFi adapter with no external antenna outside the unit and the unit has a metal enclosure, the WiFi performance is probably affected by this. The other factor is some of the LTE bands used can interfere with the WiFi frequencies.

The WiFi adapter in the Axon PLC series is designed mainly for occasional service access and/or initial setup.