Abstract: The methods provide for detecting at least one operational parameter of a functional unit of the plant and calculating a current value of at least a first statistical function of the operational parameter in a current temporal window, the current value of the first statistical function defining a first coordinate of a point of current operation of the functional unit. A step is also provided of verifying whether the point of current operation is within a range of allowable values of the first statistical function, the values contained in the range of allowable values corresponding to a correct operation of the functional unit. In case the point of current operation is outside the range of allowable values, the position is determined of the point of current operation with respect to the range of allowable values and a statistical diagnosis is provided of the cause of the deviation of the current value from the range of allowable values based on the position.

Abstract: The plant for producing a corrugated board includes one or more single facers and a double facer, as well as respective unwinders for unwinding reels of paper webs. Arranged along the production line, in suitable positions, are thermographic cameras which acquire images through which it is possible to trace the various characteristics of the cardboard, for example the moisture content thereof, detect manufacturing defects, after which it is possible to intervene on one or more process parameters so as to eliminate the causes of the defects.

Abstract: A new method is disclosed for monitoring the operation of a corrugated board production plant, the method provides for detecting at least one operational parameter of a functional unit of the plant, for example a current absorbed by a motor. Then, the current value of a statistical function of the operational parameter is calculated in a current temporal window. The maximum value and the minimum value of the same statistical function are calculated based on historicized data of the operational parameter in question. By comparing the current value of the statistical function and the maximum and minimum values, a piece of information of predictive diagnostics is obtained.

Abstract: The methods provide for detecting at least one operational parameter of a functional unit of the plant and calculating a current value of at least a first statistical function of the operational parameter in a current temporal window, the current value of the first statistical function defining a first coordinate of a point of current operation of the functional unit. A step is also provided of verifying whether the point of current operation is within a range of allowable values of the first statistical function, the values contained in the range of allowable values corresponding to a correct operation of the functional unit. In case the point of current operation is outside the range of allowable values, the position is determined of the point of current operation with respect to the range of allowable values and a statistical diagnosis is provided of the cause of the deviation of the current value from the range of allowable values based on the position.

Abstract: A new method is disclosed for monitoring the operation of a corrugated board production plant, the method provides for detecting at least one operational parameter of a functional unit of the plant, for example a current absorbed by a motor. Then, the current value of a statistical function of the operational parameter is calculated in a current temporal window. The maximum value and the minimum value of the same statistical function are calculated based on historicized data of the operational parameter in question. By comparing the current value of the statistical function and the maximum and minimum values, a piece of information of predictive diagnostics is obtained.

Abstract: An all-optical contention manager includes at least two inputs and at least two outputs. The outputs are configured to output signals to a Banyan switch. The contention manager detects and resolves routing contentions between incoming optical signals prior to outputting the signals to the Banyan switch. The signals have tags that include routing information. A photonic comparator in the contention manager compares the tags of incoming optical signals in order to detect contention.

Abstract: An optical device comprises an optical device stage, which comprises an optical input, an optical AND gate, an optical flip-flop and an optical output. The optical input is arranged to receive an optical input pulse at an input wavelength. The optical AND gate comprises a first input arranged to receive a part of said optical input pulse, a second input arranged to receive at least a part of a flip-flop optical output signal, and an output. The optical AND gate is arranged to generate an AND gate optical output pulse dependent on said flip-flop optical output signal. The optical flip-flop comprises a first input arranged to receive a further part of said optical input pulse, a second input arranged to receive a said AND gate optical output pulse, and an output. The optical flip-flop is arranged to generate said flip-flop output signal at a flip-flop output wavelength. At least a part of the flip-flop output signal is provided to said output.

Abstract: An optical linear feedback circuit has an optical loop delay path (10) for recirculating a sequence of optical signals, and an output path for outputting delayed optical signals after circulating one or more times around the loop. A selector (50) is provided for selecting one or more of the delayed optical signals from the sequence, and an optical logic circuit (20) is coupled to carry out a logical operation on the selected delayed optical signals to create an optical feedback signal which is coupled to the optical loop delay path, so that the optical feedback signal can be added to the sequence of optical signals already circulating. By recirculating around a loop, each round trip can be regarded as equivalent to a shift of a shift register, so longer sequences can be built up without needing an additional storage cell for each shift function.

Abstract: An optical flip-flop comprises first (102) and second (104) flip-flop elements arranged to respectively provide first (output 1) and second (output 3) optical outputs. Each output is in one of a plurality of states, wherein switching the output from a relatively high power state to a relatively low power state has an associated falling edge transition time, and switching the output from a relatively low power state to a relatively high power state has an associated rising edge transition time. The rising edge transition time is greater than the falling edge transition time.

Abstract: An optical transmitter apparatus comprises at least three input transmitters that each provide at an output an NRZ optical signal, at least two of the NRZ optical signals having substantially the same bit rate, each of the signals having a bit rate which is less than 100 Gbit/s and the sum of the bit rates of all of the at least three transmitters being equal to or greater than 100 Gbit/s, an NRZ to RZ converter associated with each transmitter which converts each NRZ signal into an optical RZ signal, an optical time division multiplexer which converts the RZ signals into at least two further signals, and a polarization multiplexer which processes the two further signals to provide two output signals of differing polarization.

Abstract: An optical device comprises an optical device stage, which comprises an optical input, an optical AND gate, an optical flip-flop and an optical output. The optical input is arranged to receive an optical input pulse at an input wavelength. The optical AND gate comprises a first input arranged to receive a part of said optical input pulse, a second input arranged to receive at least a part of a flip-flop optical output signal, and an output. The optical AND gate is arranged to generate an AND gate optical output pulse dependent on said flip-flop optical output signal. The optical flip-flop comprises a first input arranged to receive a further part of said optical input pulse, a second input arranged to receive a said AND gate optical output pulse, and an output. The optical flip-flop is arranged to generate said flip-flop output signal at a flip-flop output wavelength. At least a part of the flip-flop output signal is provided to said output.

Abstract: An optical linear feedback circuit has an optical loop delay path (10) for recirculating a sequence of optical signals, and an output path for outputting delayed optical signals after circulating one or more times around the loop. A selector (50) is provided for selecting one or more of the delayed optical signals from the sequence, and an optical logic circuit (20) is coupled to carry out a logical operation on the selected delayed optical signals to create an optical feedback signal which is coupled to the optical loop delay path, so that the optical feedback signal can be added to the sequence of optical signals already circulating. By recirculating around a loop, each round trip can be regarded as equivalent to a shift of a shift register, so longer sequences can be built up without needing an additional storage cell for each shift function.

Abstract: An optical logic gate (10) comprising inputs (12) for optical signals on which to perform a chosen logical operation. An SOA (11) element receives such input signals to be piloted thereby in saturation and its output is connected to at least one optical filter (14, 15, 16) that filters components of signals output from the SOA and which represent a desired logical result of the signals input at the gate so that at the output (13) of the filter there is an optical signal as the result of the desired logical operation. A probe signal (17) can also be provided. An appropriate combination of power of the input, power and probe signal wavelength and central wavelength of the filter allows obtaining a plurality of logic functions such as NOR, NOT, inverted XOR, AND, OR.

Abstract: An optical switch assembly comprising at least two optical amplifiers (10, 20), means for applying a first input signal to one end of both amplifiers (10, 20) and a second input signal to another end, and means for simultaneously driving one or other of the amplifiers into a saturated state whilst the other is unsaturated such that only the amplifier that is unsaturated provides any significant amplification to the input signals at each end, and means for feeding the amplified output signals from the amplifiers to at least two output nodes such that the two amplifiers (10, 20) are connected to the two output nodes in opposite connections.

Abstract: An optical flip-flop comprises first (102) and second (104) flip-flop elements arranged to respectively provide first (output 1) and second (output 3) optical outputs. Each output is in one of a plurality of states, wherein switching the output from a relatively high power state to a relatively low power state has an associated falling edge transition time, and switching the output from a relatively low power state to a relatively high power state has an associated rising edge transition time. The rising edge transition time is greater than the falling edge transition time.

Abstract: Improvements in or relating to Optical Networks. The invention relates to improvements in or relating to optical networks, and methods and an apparatus for providing communications services. Receiving an optical signal is described comprising a carrier wavelength and optical data. The optical data is substantially erased, and the carrier wavelength is re-modulated with user data for onward transmission of the user data.

Abstract: An optical transmitter apparatus capable of a transmission rate of at least 100 gbit/second comprises at least three input transmitters that each provide at an output an NRZ optical signal, at least two of the NRZ optical signals having substantially the same bit rate, each of the signals having a bit rate which is less than 100 Gbit/s and the sum of the bit rates of all of the at least three transmitters being at least equal to 100 Gbit/s, an NRZ to RZ converter associated with each transmitter which converts each NRZ signal into an optical RZ signal with the signal remaining in the optical domain during conversion, the optical RZ signal having the same bit rate as the corresponding NRZ signal, an optical time division multiplexer which converts the RZ signals into at least two further signals, one of the further signals being formed by bitwise interleaving the bits of the at least two of the RZ signals which have the same bit rate, and a polarisation multiplexer which processes the two further signals to pr

Abstract: An optical switch assembly comprising at least two optical amplifiers (10, 20), means for applying a first input signal to one end of both amplifiers (10, 20) and a second input signal to another end, and means for simultaneously driving one or other of the amplifiers into a saturated state whilst the other is unsaturated such that only the amplifier that is unsaturated provides any significant amplification to the input signals at each end, and means for feeding the amplified output signals from the amplifiers to at least two output nodes such that the two amplifiers (10, 20) are connected to the two output nodes in opposite connections.

Abstract: An all-optical contention manager includes at least two inputs and at least two outputs. The outputs are configured to output signals to a Banyan switch. The contention manager detects and resolves routing contentions between incoming optical signals prior to outputting the signals to the Banyan switch. The signals have tags that include routing information. A photonic comparator in the contention manager compares the tags of incoming optical signals in order to detect contention.

Abstract: An optical logic gate (10) comprising inputs (12) for optical signals on which to perform a chosen logical operation. An SOA (11) element receives such input signals to be piloted thereby in saturation and its output is connected to at least one optical filter (14, 15, 16) that filters components of signals output from the SOA and which represent a desired logical result of the signals input at the gate so that at the output (13) of the filter there is an optical signal as the result of the desired logical operation. A probe signal (17) can also be provided. An appropriate combination of power of the input, power and probe signal wavelength and central wavelength of the filter allows obtaining a plurality of logic functions such as NOR, NOT, inverted XOR, AND, OR.