Using Alarm Keypad Wiring

Long time lurker, first time poster.  Thanks for having me.  We just had a house built and and have sensors running everywhere but no alarm panel.  From another post I believe I can use those bare wires with a 12 zone kit without too much trouble.  

Can I use the keypad wiring with a 24v 48w transformer ( power a tablet and also a video doorbell?  The tablet would also have a 24v to 5v step-down behind it as well.  The wires probably have about a 25ft run.  Thanks for your help.