I have client monitor displays that I want to turn on/off automatically depending on the machine state and found this: http://systembash.com/content/how-to-turn-off-your-monitor-via-command-line-in-ubuntu/
I’m using HP t5565 and t610 Thin Clients (Debian Linux version), so I copied the monitorControl.sh file in the link to them and used the following simple code in a Client Tag Change script to turn the monitor on/off:
if newValue.value:
system.util.execute(["sh", "/home/user/Monitor/monitorControl.sh", "on"])
else:
system.util.execute(["sh", "/home/user/Monitor/monitorControl.sh", "off"])
Enjoy!