When you say " … trying to take control of a mac" you mean by using BigFix Remote Control ?
If yes I suggest you to pick up the latest Remote Control Target which contains the fix (starting from 9.1.4.0309). The screen is now powered on automatically when you connect to the Remote Control Target.
As a workaround you can try this command to wake up the screen: caffeinate -u -t3
Of course you need to be able to ssh to the mac computer.
NOTE: You need to select “Prevent computer from sleeping …” in the Energy Saver settings otherwise the computer is not reachable through Remote Control Controller, SSH, VNC or whatever other client. Probably you can enable instead the “Power Nap”.