Abstract: A measurement instrument includes selectable channels for simultaneously measuring current on a power rail/load of a device under test. Multiplexor circuitry can be controlled to select power rails/loads for measurement and to couple unselected power rails to bypass the measurement circuitry. Active loads are provided in the measurement circuitry to compensate for loading by the measurement circuitry. The active loads cause current on a source side of a selected power rail/load to match current measured on a load side of the selected power rail/load during power measurements.

Abstract: A control interface protocol governs communications in a satellite telephone system. The satellite telephone system comprises a radio antenna unit (RAU) and a plurality of desksets connected to the RAU. An interface bus connects the desksets to the RAU. The RAU and the desksets communicate with each other by packets. Each packet comprises a start of header (SOH) byte, an address number (ADDR) byte, a command (CMD) byte, an argument (ARG) and a block check character (BCC). The ADDR byte comprises a source and a destination address of the packet. All packets, except negative acknowledgment (NAK) packets from the desksets, are acknowledged by the RAU. The packets originating from the desksets are tagged with an address of the desksets. A packet to a specific deskset includes a destination address. A packet originating from the RAU to all desksets includes a first default address. A packet originating from the RAU to a deskset that does not have an address includes a second default address.

Abstract: An apparatus, system, and method for providing an audio interface between multiple deskset phones and a single radio antenna unit (RAU). The audio interface includes a transmit path and a receive path. The transmit path carries transmit signals from the multiple deskset phones to the RAU. The receive path carries a receive signal from the RAU to the deskset phones. The transmit path and receive path are electrically isolated from each other.

Abstract: A control interface protocol governs communications in a satellite telephone system. The satellite telephone system comprises a radio antenna unit (RAU) and a plurality of desksets connected to the RAU. An interface bus connects the desksets to the RAU. The RAU and the desksets communicate with each other by packets. Each packet comprises a start of header (SOH) byte, an address number (ADDR) byte, a command (CMD) byte, an argument (ARG) and a block check character (BCC). The ADDR byte comprises a source and a destination address of the packet. All packets, except negative acknowledgment (NAK) packets from the desksets, are acknowledged by the RAU. The packets originating from the desksets are tagged with an address of the desksets. A packet to a specific deskset includes a destination address. A packet originating from the RAU to all desksets includes a first default address. A packet originating from the RAU to a deskset that does not have an address includes a second default address.

Abstract: A system and a method for address assignments for wireless satellite telephone systems comprises one or more desksets (telephones) and a radio antenna unit (RAU). The desksets are connected to the RAU using an interface bus. In operation, a deskset initiates an address arbitration cycle by transmitting a request for an address to the RAU. The RAU acknowledges after it receives the request, and queries other desksets if the requested address is being used by other desksets. If no other deskset responds within a predetermined time period, the RAU grants the requesting deskset the address. If the requested address is being used, the deskset using the address informs the RAU, and the RAU rejects the request. The requesting deskset then requests a different address. If all available addresses are being used, the requesting deskset informs the user and shuts down. If two or more desksets transmit requests concurrently, there will be a collision. To resolve a collision, the desksets are divided into two sets.

Abstract: An apparatus, system, method, and computer program product for providing a flexible ringer for multiple deskset phones. A controller detects a flag message that precedes an incoming telephone call, and selects one or more frequencies based on a local expectation of a ringing telephone at the geographic location, or according to a user preference. A digital signal processor (DSP) generates a digital ringer signal based the selected frequencies. An audio code converts the digital ringer signal to an analog ringer signal and sends the analog ringer signal to multiple deskset phones using a receive cable. The analog ringer signal is amplified to drive a speaker that converts the analog ringer signal into an audible ringer sound at each deskset phone. The audible ringer sound can be customized for multiple geographic locations by modifying the selected frequencies used in the digital ringer signal.

Abstract: A control interface protocol governs communications in a satellite telephone system. The satellite telephone system comprises a radio antenna unit (RAU) and a plurality of desksets connected to the RAU. An interface bus connects the desksets to the RAU. The RAU and the desksets communicate with each other by packets. Each packet comprises a start of header (SOH) byte, an address number (ADDR) byte, a command (CMD) byte, an argument (ARG) and a block check character (BCC). The ADDR byte comprises a source and a destination address of the packet. All packets, except negative acknowledgment (NAK) packets from the desksets, are acknowledged by the RAU. The packets originating from the desksets are tagged with an address of the desksets. A packet to a specific deskset includes a destination address. A packet originating from the RAU to all desksets includes a first default address. A packet originating from the RAU to a deskset that does not have an address includes a second default address.