All new Trial accounts run in an unlimited mode and thus run all Pro collectors on the servers. If you want to continue to run Pro collectors, make sure that Pro collectors are included in the plan you choose and follow the instructions below, to segment your environment.
Existing accounts may want to switch between modes.
In either case, just follow these easy 2 steps.
1. Go to the Servers Tab and then select Configuration on the left nav. Then enter a tag to designate the servers that your want to run in Pro mode. Keep it simple, us a tag, something like "pro"
2. Then tag each server you want to run in Pro mode with the same tag "pro"
See this article for more information: