Abstract: Unusual waveforms are defined in terms of how many "new" pixels are affected by the process of rasterizing them. New pixels can be those not yet affected by the rasterization of any waveform in the current set of acquisitions, or to be those that have had higher values in their raster memory location but have now been decayed to below a defined value. Once detected, such waveforms can be re-rasterized with extra intensity or into a different color by using a reserved range of values of those storable in the raster memory. Alternatively, the special region of values can be used as a counter/timer to maintain the pixels associated with unusual waveforms at a brightest intensity value, or in the color equivalent, for an extended period of time. User input can be used to affect the definition of "new" pixels and to control the special persistence given to unusual waveforms. Unusual waveforms can also be saved in long term memory.

Abstract: A monitoring OAM (operation administrating monitoring) cell assisted method to detect bit errors occurring in ATM useful cells on an ATM transmission link generates first control bits by evaluating bits of ATM useful cells with a selected target address in the cell head prior to feeding the ATM useful cells into the ATM transmission link, whereupon the first control bits are Abramson-encoded to generate further, second control bits. The first control bits are additionally encoded to produce additional, third control bits, all of which are entered into the monitoring OAM cells and transmitted on the ATM transmission link with the ATM useful cells. At a receiver decoder the ATM useful cells are separated from the monitoring OAM cells, the monitoring OAM cells are error detected and corrected where necessary using the second and/or third control bits to provide error-free OAM cells, the first control bits of which are used to detect bit errors in the ATM useful cells.

Abstract: An apparatus for providing a probing interface for a circuit under test exhibits a relatively narrow profile and a vertical orientation so that it does not block access to connectors in adjacent slots. The vertical orientation is made possible by the use of a circuit material comprising alternate sections of flexible material and rigid material. Advantageously, the signal lines between the circuit card under test and its motherboard are direct and relatively short, and the probing connection points are isolated from the direct signal lines by a plurality of isolation resistors. The probing adapter includes the capability of monitoring the bus of the system under test and disassembling monitored AGP codes.

Abstract: An electronic instrument includes a housing having opposed end surfaces each including a handle mount. A bail handle with an elongated middle portion has extending arms connected at opposite ends, and the arms have free ends for connection at the handle mounts. The handle pivots between a first stable position and a second stable position about a pivot axis passing through the handle mounts. A pair of detent mechanisms each have a first portion connected to the housing, and a second portion connected to the handle, and each detent mechanism includes a spring which urges the first and second portions toward each other along the pivot axis.

Abstract: A method for rasterization of a set of voltage-versus-time data-address pairs into horizontal and vertical locations of a multi-bit raster display memory of a digital oscilloscope or similar electronic data acquisition instrument is disclosed. It provides a new way of controlling digital intensity, by allowing the operator and/or a function based on the instrument's trigger rate to set the number of intensity units available for brightening the pixels affected by the rasterization of each acquisition data pair. If a vector has more pixels than there are units of intensity available, the number of pixels that are to be brightened is limited but spread out over the vector's length by an algorithm that includes at least some degree of randomization. If there are more units of intensity available than there are pixels to put them in, the extra ones can either be distributed into each pixel or randomly added along the vector or ignored.

Abstract: A method for measuring by means of a mobile auxiliary device, quality determining parameters of a communications transmission link which is firmly connected to at least one end thereof and includes a central measuring system. Precise determination of the quality determining parameters in one partial link (7) of the communications transmission link, the invention provides for the auxiliary device (12) to transmit a control signal to the measuring system (25). After receipt of the control signal in the measuring system (25), the communications transmission link is subdivided into two partial links (7, 8). Subsequently, it is verified in the measuring system (25) which of the partial links the auxiliary device (12) is connected to, after which the quality determining parameters of the verified partial link (7) of the communications transmission link are measured.

Abstract: A method by which a microprocessor based handheld multi-meter, or other handheld electronic instrument, can communicate with a computer or other microprocessor based device through the measurement input jacks of the handheld multi-meter. A handheld meter, thus equipped, can receive control or calibration data from, and provide test or calibration data to, a host computer or microprocessor based accessory or other instrument. To enable this capability, the handheld meter employs dual-signal, single-axis jacks, for example split banana jacks, for one or more of its signal and ground receptacles. The handheld meter and the computer, or another microprocessor based instrument or accessory device that the meter is to communicate with, are equipped with mutually compatible software and appropriate hardware to support single signal path communication.

Abstract: A logic analyzer uses a single tapped delay line and a single array of sampling cells for high speed digital signal acquisition, by controlling both edges of a substantially 50% duty cycle clock signal to drive a delay line buffer chain. The chain operates continuously; there being no need for interruptions for precharge intervals. Thus, the need for a second delay line buffer chain is eliminated.

Abstract: A dynamically controlled timing signal generator includes a source of a controlled current, a timing signal generating circuit coupled to the controlled current source for generating the timing signal, and a feedback circuit coupled to the controlled current source for controlling the controlled current source to produce a desired controlled current.

Abstract: A very long linear input array capable of acquiring long series of acquisition data is achieved by breaking the long linear array into a series of sub-arrays, each enabled by a "global" set of enable signals. The individual cells of the local arrays are addressed by local x-y enable signals. This arrangement permits the acquisition of very long record lengths, without sacrificing the quality of other aspects of the acquisition process to excess capacitance.

Abstract: A real-time data display in a control window of a measurement instrument receives real-time data corresponding to an application, wherein the real-time data is to be displayed to a user. A control window is also displayed, including one or more user-selectable options within the control window and at least a portion of the real-time data within a portion of the control window. A user selection of an option to alter a display of the real-time data is then received, and the real-time data being displayed is altered within the portion of the control window in accordance with the user-selected option.

Abstract: An apparatus and method for deriving a signal from the AC line and conveying it to processing circuitry employs two wires each of which is non-conductively attached and capacitively coupled to a respective one of a two-wire AC power line. Each of the capacitive pick-offs is coupled to a respective input of a differential amplifier for amplification. Advantageously, because the output signal is a replica of the AC power line signal, the detection threshold can be set at or near zero volts. This makes the detection point insensitive to the amplitude variations of the AC power line. In one embodiment, an output signal is developed at a single ended output of the differential amplifier, and applied to a low pass filter to remove undesired higher frequencies. A further amplifier provides greater amplification of the filtered representation of the AC power line signal, and includes an amplitude limiting circuit to accommodate the wide range of AC line voltages which may be applied to the instrument.

Abstract: An adapter suitable for use with a handheld multimeter and a thermocouple probe contains a temperature sensor and input connectors suitable for mating with standard thermocouple probes. Both of these are closely coupled thermally to an isothermal domain. Plugs suitable for mating with the input jacks of a handheld multimeter are disposed within the adapter on the other side of a high thermal resistance zone. Conductors connect these outputs to the input connectors and to the leads of the temperature sensor. A four output version of the adapter is shown for use with a three lead temperature sensor, and a three output version is shown for use with a two lead temperature sensor. The output plugs can paired to be more compact and easier to use through the use of dual-signal single-axis banana plugs.

Abstract: A multi chip module with a substrate having a network of a plurality of electrical interconnects and a number of electronic components mounted to the substrate and connected to the network. A monolithic test chip having a number of identical functional regions is mounted to the substrate and electrically connected to the network. Each functional region on the test chip is independently connected to the substrate and is electrically isolated from the others. The chip may be produced by preparing wafers with a grid of identical functional elements, and cutting up the wafers into chips of different sizes, depending on the application.

Abstract: The invention relates to a method for determining the transmission characteristics (H(jf)) of an electric line (2) in an ISDN system, in which a test signal (m(t)) is applied to the line (2) at one end, and at the other end of the line (2) the received signal (g(t)) produced owing to the test signal (m(t)) is evaluated.In order to be able to carry out such a method using a test signal having a crest factor of one with relatively little cost, use is made as test signal of a binary, bipolar random number sequence signal (m(t)) having the crest factor of one, and during a time interval corresponding to the period of the test signal (m(t)) the received signal (g(t)) is scanned and subjected to a Fourier transformation to obtain a spectral signal (G(jf)); the latter is complexly multiplied by a reference spectrum Mi(jf) to obtain an output signal (H(jf) which represents a measure of the transmission characteristics of the line (31).

Abstract: A method and apparatus for measuring the RMS value of an electrical signal. An electrical signal is converted to a digital signal. The digital signal is squared and low pass filtered to extract the DC component, the DC component being recognized as the mean-square of the signal. In use in a measurement device, the square root of the DC component is taken and displayed as the RMS value of the electrical signal.

Abstract: A monitoring OAM cell assisted method enables continuous intrasystem determination of bit errors which have occurred in ATM useful cells with a useful information field and a cell head on an ATM transmission link. First control bits are generated by evaluating bits of ATM useful cells with selected target addresses in the cell head prior to feeding the ATM useful cells into the transmission link, and the control bits are additionally encoded to generate second control bits. The first and second control bits and OAM cells are then transmitted along with the ATM useful bits. The second control bits of the monitoring OAM cells are received at the far end of the ATM transmission link and examined for errors to determine if the monitoring OAM cells were received without error. The first control bits are used to determine if the useful ATM cells were received error-free.

Abstract: A card guide allowing or impeding airflow to a circuit card uses overlapping airflow shutters disposed longitudinally along the bottom of the card guide. The shutters are operated in response to the insertion of a card into the card guide by the action of a panel of the circuit card engaging an actuating member on the card guide assembly. When open, the shutters provide an opening which exceeds fifty percent of the airway.

Abstract: An apparatus for providing a probing interface for a circuit under test exhibits a relatively narrow profile and a vertical orientation so that it does not block access to connectors in adjacent slots. The vertical orientation is made possible by the use of a circuit material comprising alternate sections of flexible material and rigid material. Advantageously, the signal lines between the circuit card under test and its motherboard are direct and relatively short, and the probing connection points are isolated from the direct signal lines by a plurality of isolation resistors.

Abstract: A system and method for locating a data sample in a logic analyzer or emulator acquisition buffer corresponding to a source code statement employs first and second windows, wherein one window displays the contents of the acquisition buffer, for example, in disassembly form and the other window displays source code. When a source code file is displayed and a specified statement is selected within the source code, a search for a matching sample in the acquisition buffer is initiated. If a sample is found, it is displayed and highlighted in the appropriate window.