Fix Dahua VTO Unlock

I have a Dahua VTO door station paired with three VTH indoor LCD monitors. Everything talks to each other—video, audio, call-throughs—yet when I press “Unlock” from any VTH panel or through the DMSS mobile app the voice prompt says “Successfully unlocked”, but the door’s electric strike never fires. No click, no movement. Here is the current setup so you can jump straight to the root of the issue: • The strike is powered by its own 12 V supply and its two wires run straight to the VTO relay contacts (NO/COM). • Lock type: standard electric strike. • When “Unlock” is pressed I hear nothing from the strike, so the relay either isn’t switching or the wiring/polarity/timing is off. I need a Dahua-savvy technician to: 1. Review my relay wiring diagram or photos and confirm correct NO/NC selection and jumpers. 2. Walk me through the VTO/VTH lock parameters (open duration, door sensor settings, control type—local/remote) via ConfigTool, Web GUI or SmartPSS. 3. Help me test voltage at the relay during an unlock command to confirm whether the fault is in configuration or hardware. 4. Stay on the call until we achieve a reliable “click” and the door actually releases. We can screen-share for the software side and I’ll handle the multimeter on my end. Once the strike activates consistently from all three monitors and DMSS, the job is done.