Built-in Self-detection device to avoid hand-up.
Provide emergency mode contact to eliminates all floors access control.
Function with Chiyu door controller only, compatible with BF-670 / BF-870 / SEMAC-S3.
No limitation for user control, you can just use card number and group setting to control floor, that way will be much easier for system integration.
Built-in 16 relay Output. When there are over 16 floors, you can connect more BF-333 to extend the floor control number. You can connect 8 pcs of BF-333 to control 128 floors at the most.