Abstract: Control circuitry is coupled between an error event output and a data input of a pseudorandom binary sequence (PRBS) checker. The control circuitry is configured to switch between a first operating state in which a received PRBS signal is applied to the data input of the PRBS checker and a second operating state in which an error signal is applied to the data input of the PRBS checker, responsive to detection of a designated condition of the PRBS checker. In an illustrative embodiment, the designated condition is an end-of-test condition indicating that the PRBS checker has completed a test involving the received PRBS signal.

Abstract: Devices to be arranged in a master-slave configuration are individually tested using a testing system that ensures that the devices will satisfy an interconnection requirement of that configuration. The testing system configures a first device into one of a master mode of operation and a slave mode of operation, and adjusts frame starting positions of respective traffic flows associated with the configured mode until measured delay parameters of that mode substantially match corresponding ones of a selected set of prospective delay parameters. If the traffic flows of the one configured mode as adjusted are substantially error free, the first device is configured into the other mode, and frame starting positions of respective traffic flows associated with the other configured mode of the first device are adjusted until measured delay parameters of that mode substantially match corresponding ones of the selected set of prospective delay parameters.

Abstract: In one embodiment, the present invention is a framer/mapper/multiplexor (FMM) device that can simultaneously (i) send protection copies of both its working incoming high-speed (e.g., STS-12) signal and incoming low-speed signals to a protection FMM device, and (ii) receive corresponding protection signals from the protection FMM device. Furthermore, the FMM device can select between working and protection signals at a switching level (e.g., STS-1) lower than the high-speed level, allowing for 1+1 APS/MSP protection and equipment protection at the board level, the device level, and at the STS-1 level. Yet further, four or more FMM devices can be configured so that all FMM devices can communicate with their corresponding protection FMM devices using a single, shared, 4-pin link (e.g., quad-OC-3 mode), and still select between working and protection signals at the switching level (e.g., STS-1).

Abstract: In one embodiment, the present invention is a framer/mapper/multiplexor (FMM) device that can simultaneously (i) send protection copies of both its working incoming high-speed (e.g., STS-12) signal and incoming low-speed signals to a protection FMM device, and (ii) receive corresponding protection signals from the protection FMM device. Furthermore, the FMM device can select between working and protection signals at a switching level (e.g., STS-1) lower than the high-speed level, allowing for 1+1 APS/MSP protection and equipment protection at the board level, the device level, and at the STS-1 level. Yet further, four or more FMM devices can be configured so that all FMM devices can communicate with their corresponding protection FMM devices using a single, shared, 4-pin link (e.g., quad-OC-3 mode), and still select between working and protection signals at the switching level (e.g., STS-1).

Abstract: Control circuitry is coupled between an error event output and a data input of a pseudorandom binary sequence (PRBS) checker. The control circuitry is configured to switch between a first operating state in which a received PRBS signal is applied to the data input of the PRBS checker and a second operating state in which an error signal is applied to the data input of the PRBS checker, responsive to detection of a designated condition of the PRBS checker. In an illustrative embodiment, the designated condition is an end-of-test condition indicating that the PRBS checker has completed a test involving the received PRBS signal.

Abstract: A frame fork for a bicycle includes a main tube, two support tubes, a fork head including a bracing tube and two legs integrally formed together, and a sleeve including a sleeve body and two limbs integrally formed together. A center hole is formed in the sleeve body. The bracing tube passes through the center hole of the sleeve body and the lower end of the main tube. The sleeve body embraces the lower end of the main tube. Each leg of the fork head and a respective limb of the sleeve are force fitted into each upper end of the support tube.