I have setup virtual temperature sensors as an over lay on a data centre floor layout.
In map settings "show value is ticked" and on initial setup values were displayed for each virtual sensor..
The next day only some of the sensors have the value displayed
When you re-select each sensor in "Map label settings" the values re-appear but disappear again when you save.
The value is there if you hover the cursor over the sensor.
Check time settings on your Netbotz (I suppose that you use Netbotz because of virtual sensors :))
Date and time should be close to date and time configured on DCE server.
Good practice is to set up similar NTP source for DCE and Netbotz or configure DCE to act as NTP for monitored devices.
Thanks for your reply.
The physical sensors are connected to Sinetica Eagle-i boxes which are using the same NTP server settings as StruxtureWare.
In one case there are 8 physical temperature sensors connected to an Eagle-i box. I've made a virtual temperature sensor for each physical sensor. Half of them show values and half don't.
I have found a solution but it's not very practical.
If after a day of creating a virtual temperature sensor the value disappears you have to delete the sensor and recreated it again.
Eventually after a few days of doing this the value sticks.
Must be a bug in the system.
This has to be done early in the sensors life or you could loose a lot of historical data.