Hi!
Let me describe the whole configuration process for DS18x20 sensors on RPi in case if someone needs this later.
A pull-up resistor of 2..10KOhm should be connected between DQ pin of the sensor and +3.3v. GPIO2 and GPIO3 have built-in 1.8KOhm pull-up resistors (at least on RPi 3), so if you don't need I2C, you can connect the sensor to one of these pins.
A kernel module is used to communicate with the sensor. It is activated ty adding dtoverlay=w1-gpio to the end of /boot/config.txt file.
By default the DQ pin of the sensor should be connected to GPIO4, to use another GPIO the following format could be used: dtoverlay=w1-gpio,gpiopin=3. Reboot RPi when finished editing the file.
Since kernel version 4.9.28 it's also possible to use dynamic overlay loading: sudo dtoverlay w1-gpio gpiopin=5, in this way it's possible to have sensors on several GPIO pins.
After restart (of after dynamic overlay loading) the sensors should get detected:
root@raspberrypi:~# ls /sys/bus/w1/devices/
28-6cb0611f64ff w1_bus_master1
here we have one sensor connected, it has name 28-6cb0611f64ff
4) And we should be able to read the temperature:
root@raspberrypi:~# cat /sys/bus/w1/devices/28-6cb0611f64ff/w1_slave
78 01 55 00 7f ff 0c 10 57 : crc=57 YES
78 01 55 00 7f ff 0c 10 57 t=23500
which in this case is 23,5 degrees C.
5) To configure NetXMS agent we add the following lines to /etc/nxagentd.conf
SubAgent=ds18x20.nsm
[DS18X20]
Sensor = Test:28-6cb0611f64ff
After agent restart systemctl restart nxagentd our parameter "Test" should return the temperature.
user@netxms-server:~$ nxget raspberrypi.lan 'Sensor.Temperature(Test)'
23.312
Your configuration looks exactly the same. The thing is that the error message in agent log "Unable to add sensor from configuration file. Original configuration record:" looks to be a bug, i am also getting it (as of v. 3.1.274). But the parameter works. Most probably on your system Sensor.Temperature(Test) will also give the result.