Hi Joe
One excellent ascom compliant relay and sensor unit is Lunatico Astronomia’s Dragonfly, here. It is an observatory controller and you can use it not only to send a pulse to trigger your roof motor but also power on/off your equipment, link to your weather station and a myriad of other tasks.
I use one in my home observatory and also my shared remote observatory at e-Eye, Spain. The software comes with ascom compliant scripts for your roof and it works seamlessly with SGP.
If your budget can stretch to the Dragonfly, it is a superb piece of very versatile equipment. Jaime at Lunatico is very helpful and gives very good customer service. He also has been known to post on here . . .
There are other usb/ethernet switch relays available, eg KMTronic and you could build your own scripts of course.
HTH.