Manage service properties and datapoints

Hi!

I am using services in order to group some network interfaces and calculate the total traffic of the group as the sum of the different inbound/outbound Mbps traffic values polled for the network interfaces.

I would also need to calculate the % of inbound/outbound bandwidth usage using the speed in Mbps available for the group. 

This speed value is stored in a property created in the service instance that is configured using a manual value (e.g. 200 Mbps):

I have also created a complex datapoint for this value, using the ##property## syntax:

Unfortunately, the complex datapoint is not collecting any data:

Are the same rules that work for resource datapoints applied to service datapoints?

Is there any way to use the property values of the resources that belong to the service?

Thanks!