The AVI-SC-509 is an import proximity Time & Attendance system. It adopts a sophisticated proximity communication protocol called PSK and encrypts a proximity card to check the identities of employees as well as visitors to your facility. This is much safer and more reliable than those without encrypted proximity cards. It offers 3 different operation processes: Using a five digit code Using the proximity card directly Using both the proximity card and a five digit code believe to be the most ideal option When a user attempts to open a door in your office or factory that has been protected, an intimidating card or code is used to output a soundless alarm signal through an auto-dial machine which is, in turn, connected to the alarm system. The anti-pass function is optional, which prevents a person who has no authorization from following others who are entering the building. The input and output interface of the SC Series can also be programmed to link other exterior system accessories. For example, if the door was not closed in time, the relay will trigger an audible alarm which also becomes a part of the daily log like all other activity. The SC Series of access control products are marvels of technology. They have been developed using the LINUX operating system and deploy an USB flash disk to download data. The AVI 509 also features a message function which displays a reminder message on the LCD screen on a pre-specified date and time when an authorized individual checks in. The SC Series also has an inner background light to help improve LCD and keypad usability. It can work as an independent stand alone device and maintain records in real time which you can also transfer to your work station. It can also be managed by PC through RS232, RS485 or the TCP/IP Internet protocol. This series is certified by CE, UL, FCC and MIC.