1. Extension board use for following elevator
2. logic board.
3. No supply voltage requirement.
4. On board number of stops 8. (8 landing call & 8 car call).
5. Maximum 5 cards we use at a time.
6. Easy connection with Main logic board & other extension card with the FRC (Flat Ribbon Cable).
7. Status of all inputs & outputs though LED indication on board.
8. No need of change any parameter in Main Elevator Logic board, just change Maximum Number of Floor.