Keri's PXL-500 Controller hardware platform provides sophisticated access control solutions for up to 256 doors at a single site and thousands of doors spread over a number of remote sites. The unique architecture allows Keri to offer the system hardware at a lower cost compared to other manufacturers. It also contains many features that simplify and significantly reduce the cost of installation. The system is managed by Keri's Doors. NET software. Reduces installed cost of access control Expandable 1 or 2 Doors at a Time Support for Either Keri Proprietary Credential Format or Wiegand Credential Format On-Board Diagnostics Self Configuring Controller 256 Door/65,000 User Capacity (Site) Up to 5 Year Memory Retention.