Hey everybody—this is Part 2 of my GDS learning journey, and in this video I focus on relay wiring with the Grandstream GDS3725 to trigger an electric door strike. I walk through what the terminals mean on the back of the unit (especially NO and NC—normally open and normally closed), because you really have to understand those to wire the relay correctly. I’m learning this hands-on through trial and error plus Grandstream documentation, so full disclosure: I’m not an electrician. If you’re not comfortable doing this kind of work, please consult a certified electrician. From there, I explain and demonstrate the two common approaches: fail secure versus fail safe. In fail secure, the strike stays locked with no power and unlocks when power is applied. In fail safe, it’s the opposite—the strike is unlocked with no power and locks when power is applied. I also show the basic wiring assumptions (I’m powering the GDS via PoE) and I walk through both wiring diagrams, including why I install a diode across the strike for surge protection (band toward the positive side). By the end, you’ll know which terminals to use and how to think through the power path for each mode.