Card reader for time and attendance

A method of operating a card reader in a security system having a central controller and plural remote card readers wherein the central controller and each of the remote card readers cooperate to each define separate electrical communication systems, the method, comprising:

• reading card data from cards inserted in a selected card reader, with read cycles initiated at a rate determined by the frequency of card insertions at said reader;
• storing said card data in a memory at said reader;
• producing an authorization signal in said card reader, independent from the central controller, in response to appropriate data read from the card;
• and
• transmitting said card data from said memory to said central controller at a rate determined by the electrical communication system associated with said card reader.

A card reader for use in a security system having a central controller and a plurality of said card readers, which controller keeps the time of day, wherein the central controller and each card reader are electrically connected so as to each define an electrical communication system, each said card reader comprising:

• means for reading data stored permanently on a card;
• means for keeping local time at said card reader synchronized with the time at said central controller but offset from it by a predetermined amount;
• means for storing the data read from said card by said reading means and for storing said local time at the time the card was read;
• means in said reader for authorizing or refusing authorization independent of the central controller, based upon the data on said card and for causing said data read from said card and said time of day to be stored in said storage means at a first time;
• and
• means for communicating data stored in said storage means to said central controller at a time controlled by the electrical communication system associated with the card reader.