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 @Stoeffel ,

it seems that you access the serial (RS485) line from multiple applications which confuses Evok. Can you try to disable other processes potentially working with HW and leave running Evok only?

Hello @smontosa,

please try to download the current version 2.4.10. The issue should be fixed. Please note that watchdog settings (same as other parameters) are stored in RAM memory by default. To burn it into non-volatile memory (FLASH), use the appropriate coil 1003 or call the separate REST request on the same endpoint with parameter nv_save=1.

Hello @Stoeffel,

the issue should be fixed in the current release. Please upgrade to version 2.4.8.

Hello @DAWaller,

can you please describe your application in more detail? Websocket connection is provided by Evok software. Node-RED uses this type of connection to communicate with the I/Os.

Do you see the connection outages from Node-RED running on the same unit?

What displays the Node-RED debug console?

Hello @mglowinski,

sorry, but this feature is not supported in Unipi 1.1 series products. Please consider buying Neuron/Patron series PLCs which can do it.

Hello,

unfortunately, the Unipi 1.1 does not have a watchdog device. You can see all available devices/circuits in reply to the "all" GET request. Example (can be invoked from your web browser):

http://<your_unit_IP>:8080/json/all

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).