Business ideas

Hi all what would be good if we could link two alarm together mean alarm one need to be set before alarm 2 set This would work for house aswell where one alarm would set my gate at the back before we can set the house would work for home office aswell So it be like alarm 1 ans 2 need to be set before alarm ans can be add more to it for e.g for house i have a outside office where i have a ring alarm in and have other in my house mean before i set my house alarm my outside officer need to be set before setting the house is would be setting setup alarm before set be link to a alarm if this was something i would buy 4 more alarm