How to turn off an external display without disconnecting? I have a workplace setup for my Macbook Pro 15" (2011) that is actually two workplaces. One is the Macbook itself, for sitting. The second, right next to it, is a standing desk with an external monitor, keyboard, and mouse.

This works great - I can work on the standing desk, and when my legs get tired, sit down for a while and continue seamlessly on the Macbook.

The only painful point in the transition is that I have to physically disconnect the external display (an Acer 23" display connected through a MiniDP-to-HDMI cable) when sitting down, so the Macbook display becomes the main (and only) desktop again. 

Given that I may do this several times a day, this is bound to wear out the connector over time, something I'd like to avoid. 

Is there a more sustainable (software-only?) way to disconnect / deactivate an external display?

All I can find on the Google is about the other way round (turning off the internal Macbook display).
There are two solutions I can think of:


SwitchResX
Power plug adapter with remote control


SwitchResX has a number of features including "disable display" which should deactivate it until the software  turns it back on.  From their FAQ:


  SwitchResX includes a function to remove a display from the System's
  list of managed display. This means the display in question, once
  deactivated, will not be visible from the System or from any
  application. Only SwitchResX will be able to activate the display
  again.


Another simple solution is to use a power plug with a remote switch.  It's an easy, non-invasive solution that will get the job done without having to install software or have daemons running that could interfere with your display.  macOS will not detect the display if the power is cut (though it will if it's in "standby" or "sleep")



Both solutions cost about the same (less than $20USD).  SwtichResX has a 10 day free trial and the power adapter comes with a 30 day return.  The software has the benefit of being elegant; but the switch, though a bit crude, has the advantage of you knowing for sure you display is disabled because it's physically off.