Abstract: In one aspect, the invention features a fiber optic receiver that includes a preamplifier circuit incorporated together with an opto-electronic transducer in a receiver optical sub-assembly (ROSA), and an adjustable bandwidth post-amplifier that is located outside the ROSA to allow the overall size of the receiver package to be reduced. The ROSA is mounted on a substrate and is fitted with a fiber optic connector for coupling to a mating connector of a fiber optic cable. The opto-electronic transducer is incorporated within the ROSA and is configured to generate an electrical data signal in response to a received optical data signal. The preamplifier circuit is incorporated within the ROSA and is operable to linearly amplify an electrical data signal generated by the opto-electronic transducer. The adjustable bandwidth post-amplifier circuit is mounted on the substrate and is coupled to an output of the preamplifier circuit.

Abstract: A module that detects a password at a hidden address in order to implement a change in an address scheme. The module includes a bus and a memory having a memory address which is coupled to the bus. The module further includes an interface-comparing circuit that monitors data traffic on the bus and receives a predetermined password. The module still further includes a password-comparing circuit which is coupled to the interface-comparing device and allows access to the memory in response to the interface-comparing circuit receiving the proper predetermined password. Such a module can implement a change in the module's configuration or operating characteristics. Such changes include acknowledging a new memory address into the address scheme, unacknowledging an existing memory address in the address scheme and downloading a new operating program having a new address scheme to a controller coupled to a second bus.

Abstract: A system comprises a first conductor configured to receive a signal via a supply side gas pipe, a second conductor configured to receive a reference signal via a reference path, and a circuit coupled to the first conductor and the second conductor. The circuit is configured to receive the signal and the reference signal to provide power to the system.

Abstract: An optical transceiver module includes a laser configured to provide an optical output signal having a power level that is based on a bias current. The optical transceiver module includes a controller is configured to cause the laser to be biased with an initial bias current, to receive a monitoring signal indicative of the power level, to compare the power level to a desired power level range, and to cause the laser to be biased with an adjusted bias current if the power level is not within the desired power level range.

Abstract: A system comprising a host and a transceiver coupled to the host is provided where the transceiver is configured to receive a request from a host and cause a test mode of operation to be entered in response to receiving the request.

Abstract: A module that detects a password at a hidden address in order to implement a change in an address scheme. The module includes a bus and a memory having a memory address which is coupled to the bus. The module further includes an interface-comparing circuit that monitors data traffic on the bus and receives a predetermined password. The module still further includes a password-comparing circuit which is coupled to the interface-comparing device and allows access to the memory in response to the interface-comparing circuit receiving the proper predetermined password. Such a module can implement a change in the module's configuration or operating characteristics. Such changes include acknowledging a new memory address into the address scheme, unacknowledging an existing memory address in the address scheme and downloading a new operating program having a new address scheme to a controller coupled to a second bus.

Abstract: A communication module operable to receive and transmit signals. The communication module includes a controller having a memory. The memory is operable to store a program, called a personality, having a plurality of performance characteristics for the receiving and transmitting of digital signals using the communication module.

Abstract: A communication module includes a switch circuit operable to connect an internal bus to an external bus for, e.g., diagnostics, verification, and fault analysis. The internal bus allows data communication between electronic components internal to the communication module, and the external bus allows data communication between at least one internal electronic component and a device external to the communication module. The switch circuit may be controlled via a programmable and password protected register within the communication module.

Abstract: An optical transceiver module for optical communication includes a transmitter, a receiver, and a controller. The controller is coupled to the transmitter and receiver and includes a transceiver operating code. The transceiver operating code includes a plurality of task code modules, with each task code module containing instructions for performing at least one task of a plurality of tasks for controlling the optical transceiver module, and each having an assigned priority level. The transceiver operating code further includes a priority code configured to control the order in which the controller executes the plurality of task code modules based on the assigned priority levels.

Abstract: A transceiver that includes a transmitter, a controller, and a memory accessible by the controller where the controller is configured to receive failure analysis information from the transmitter and store the failure analysis information in the memory is provided.

Abstract: An optical transceiver module includes a laser configured to provide an optical output signal having a power level that is based on a bias current. The optical transceiver module includes a controller is configured to cause the laser to be biased with an initial bias current, to receive a monitoring signal indicative of the power level, to compare the power level to a desired power level range, and to cause the laser to be biased with an adjusted bias current if the power level is not within the desired power level range.

Abstract: An optical transceiver connectable to a test apparatus. The optical transceiver includes a least one test apparatus interface configured to receive from the test apparatus an input causing at least a first transceiver operating parameter to have a level substantially equal to a known value, at least one sensor configured to measure a level of at least one transceiver operating parameter including the level of the first transceiver operating parameter, a data interface configured to provide a value representative of the level of the first transceiver operating parameter, and a controller. The controller is configured to receive and convert the representative value to an actual value using a defined function having a plurality of predetermined coefficients and to provide the actual value to the test apparatus via the data interface.

Abstract: In one aspect, the invention features a fiber optic receiver that includes a preamplifier circuit incorporated together with an opto-electronic transducer in a receiver optical sub-assembly (ROSA), and an adjustable bandwidth post-amplifier that is located outside the ROSA to allow the overall size of the receiver package to be reduced. The ROSA is mounted on a substrate and is fitted with a fiber optic connector for coupling to a mating connector of a fiber optic cable. The opto-electronic transducer is incorporated within the ROSA and is configured to generate an electrical data signal in response to a received optical data signal. The preamplifier circuit is incorporated within the ROSA and is operable to linearly amplify an electrical data signal generated by the opto-electronic transducer. The adjustable bandwidth post-amplifier circuit is mounted on the substrate and is coupled to an output of the preamplifier circuit.

Abstract: An apparatus and method are provided to correct for the amount of degradation in light output of the light source used with an electrophotographic recording medium of an optical printer. The percentage amount of degradation due to aging is predicted by measuring degradation over a short interval and used to adjust the light output of the individual LEDs by pulse width modulation or current modulation so that there is a uniform light output. Similarly, the percentage amount of degradation due to temperature changes is predicted and used to adjust the light output.