SDC 705UL1R Key Switch DPDT Controller

Overview

The SDC 705UL1R is a key switch–controlled DPDT relay module designed for multi-door access control systems where you need centralized credential switching across multiple doors. This controller handles up to 63 doors with support for 250,000 user records, making it suitable for medium-to-large facilities running mixed credential ecosystems — DESFire, MIFARE, NFC (13.56 MHz), and legacy 125 kHz proximity cards. The DPDT (double-pole, double-throw) configuration means you can switch two independent circuits simultaneously from a single key-activated input, useful when a single access event must trigger multiple strike or relay actions.

Compatibility

The 705UL1R integrates with access control architectures using OSDP (Open Supervised Device Protocol) or TCP/IP communication. It pairs with enterprise-grade credential systems supporting DESFire and MIFARE smart cards, NFC readers, and 125 kHz proximity card readers. The module is compatible with standard building management systems and third-party access control platforms that accept DPDT relay logic or direct serial/IP command streams. Verify your VMS (Video Management System) or access control panel supports OSDP or TCP/IP handshake before ordering — legacy 26-bit Wiegand-only systems may require a gateway adapter.

Installation Notes

Wire the key switch input to your access control reader or panel's credential output. The DPDT relay contacts support loads up to the controller's rated voltage and current — confirm your strike or auxiliary relay draw against the module's output specification sheet before final installation. Mount the 705UL1R in a secure enclosure or control cabinet to prevent unauthorized key access. Test credential recognition and relay closure under load before placing the system into production.