Product DescriptionZKTeco C3-400-PRO 4-Door Access Control BoardThe ZKTeco C3-400-PRO is an IP-based access control board designed to manage up to four doors in a scalable security system. This board-only controller supports Wiegand-output readers and provides flexible inputs and relay outputs for connecting locks, door contacts, exit devices, alarms, and other access-control hardware.Built-in access control functions include anti-passback, first-card opening, multi-card opening, duress password entry, and auxiliary input/output linkages. TCP/IP and RS-485 communication support dependable integration with compatible ZKBioSecurity software and networked access control installations.Key Features