There are a few things you can check if the HHD is not connecting to the lock:
1. If this is a Pideon HHD (handheld device), make sure you are logging in as Manager, not operator.
2. Make sure the HHD is attached securely by the short, black serial cable to the CIP (black box with a metal, circular piece and two prongs). Try unplugging these items and plugging them back in and jiggling/bending the cable. If moving the cable gets it working, it may be a bad cable.
3. Make sure the two prongs on the CIP are straight and have not been bent. If they have been bent, the CIP may be damaged.
4. Make sure the CIP is facing down (circular, metal piece is down).
5. Make sure the lock functions as normal. Has it been programmed yet? If not, does it go into programming mode when the programming key is used (flashes red and green). If the lock has been programmed, does it respond?
6. Make sure the HHD functions as normal and ensure that it is in serial mode as opposed to USB mode. When you are logged into the HHD, to the right of "No Device Connected" there is a square toggle that will indicate which mode you have set.
7. Try another lock and see if you run into the same issue. This will tell you if the issue is isolated to the lock.
8. If all of these have been checked, try removing the battery cover from the HHD and using the reset button to reset it. Then try again.
9. Contact the company that installed the system for you and inquire about what your options are.