Abstract: An intelligent vending system such as a pay telephone provides local/remote diagnostics, fraud prevention, capability of facilitating local coin overtime operation, complete cash box accounting, and detailed reporting. Information regarding each transaction is recorded and is useful in verification, by way of example. The system includes a delta-sigma driver for reducing circuit complexity and improving circuit reliability, and a one-wire, high speed communication controller which facilitates high speed downloading and uploading of data, records, and operating program code. Battery management techniques, memory management, and coin detection circuits add to the system's capabilities and reliability. Firmware security techniques and operating system formats also promote product firmware security and configuration control.

Abstract: An intelligent vending system such as a pay telephone provides local/remote diagnostics, fraud prevention, capability of facilitating local coin overtime operation, complete cash box accounting, and detailed reporting. Information regarding each transaction is recorded and is useful in verification, by way of example. The system includes a delta-sigma driver for reducing circuit complexity and improving circuit reliability, and a one-wire, high speed communication controller which facilitates high speed downloading and uploading of data, records, and operating program code. Battery management techniques, memory management, and coin detection circuits add to the system's capabilities and reliability. Firmware security techniques and operating system formats also promote product firmware security and configuration control.

Abstract: An intelligent pay telephone provides local/remote diagnostics, fraudulent call prevention, capability of facilitating local coin overtime operation, complete cash box accounting, and call detail reporting. Information regarding each call placed from the telephone is recorded and is useful in verifying operator service provider communications, long distance bills, local measured usage charges, and call volume discounts, by way of example. The intelligent pay telephone includes a delta-sigma voice driver for reducing circuit complexity and improving circuit reliability, and a one-wire, high speed communication controller facilitates high speed downloading and uploading of pay telephone data, records, and operating program code. The pay telephone also includes a low impedance, low power hookswitch for resisting damage from weather, as well as a pin fraud prevention circuit for deterring fraud.