Domotz allows you to monitor TCP Services and SNMP (v1, v2, v3) objects available on your connected devices.
Learn more about SNMP Monitoring.
Learn more about TCP Monitoring.
If you are not familiar with the SNMP protocol, here is a blog post describing its main characteristics.
Here you can also find a useful example of monitoring Server Room Temperature using SNMP Sensors.
Domotz SNMP and TCP usage and sampling configuration
All SNMP sensors and TCP services configured within Domotz are listed in a specific section, accessible from the right side of the menu of the Device List of an agent:

This page will give an overview of all the SNMP/TCP configured and will allow you to change the sampling frequency of the Domotz SNMP and TCP monitoring (increasing the frequency will decrease the number of SNMP/TCP you can monitor):

SNMP/TCP sensors limit with examples
Premium/Standard plan
The Premium/Standard plan allows 900 sensor readings every 30 minutes (Its default frequency is 30 minutes.) allows the user to monitor 900 sensors.
NOTE: the total amount of sensors you can add to an agent is also a function of the frequency. The higher the frequency, the lower is the total number of sensors.
For example, increasing the monitoring frequency (for example, every 5 minutes) reduces the number of sensors available (900 / 6 = 150, where 6 = 30 minutes / 5 minutes).

Booster Pack
The booster pack allows for 7500 sensor readings every 30 minutes. if you increase the frequency that limit will decrease.

For example, the Booster pack allows you to monitor 7500 sensors at a low frequency (every 30 minutes) and 500 sensors at a higher frequency (every 2 minutes)
