Advantages of using logic probes in oscilloscopes
The MSO4000 series includes 16 digital (logic channels) and two/four analog channels. In some similar MSO products, the interface of the logic probe is placed on the back of the instrument, and most users find the connection at this location very troublesome and difficult to see. In contrast, the P6516 probe combines all 16 digital signals into a single input connector on the instrument's front panel. By using the front panel interface, users can easily connect and remove the P6516 probe to and from the oscilloscope.
8-channel adapter clip supports long-distance measurement
The probe's 16 channels are divided into two 8-channel "adapter clips," which connect to the oscilloscope via a flat ribbon cable up to 4 feet (122 cm) long. It is very important that the ribbon cables and individual channel leads are strong coaxial cables that are "flexible enough" to be easy to manage, but not easily tangled. This way, engineers can now probe test points up to 8 feet (244 centimeters) apart, which is enough distance to cover a 3-bay, full-height rack system. Because coaxial cable is used throughout the entire path from the probe tip to the instrument, signal fidelity is maximized while external noise and crosstalk interference are minimized.
Color coding eliminates connector confusion
On each adapter clip, the coaxial cable color for the channel with the smallest sequence is blue for easy identification. A common practice in testing is to connect the digital leads in Bit order on the parallel bus, that is, Channel 0 connects to Bit 0, Channel 1 connects to Bit 1, and so on. The blue leads are connected to the least significant bits in the corresponding 8-channel group, making it easier to trace this sequence.
Second, more advanced color-coded markings accurately link specific adapter clip channels to corresponding tracks on the display. Each channel in the 8-channel adapter clip is marked with a color code corresponding to the adapter clip base and probe head resistor, and the trajectory of the specific channel is drawn on the MSO4000 series display. This signal color coding on the MSO4000 Series speeds understanding of measurement results while minimizing errors.
With designers focusing all their attention on digital connections, it's easy to overlook the insignificant ground terminal. Most current instruments have a ground wire with a fixed length and terminals specified by the manufacturer. Unfortunately, the ground wire may be missing, or the fixed length may not be ideal for the application (e.g., the backup wire may be too short to reach a distant chassis ground point). The P6516 probe is unique in that it uses a commercial self-propelling lug to connect the ground wire to the adapter clip. Users can cost-effectively ground cables of custom lengths without the need for proprietary components.
make contact
Probe heads must meet both the electrical and mechanical requirements of digital devices of all shapes and sizes. One of the first requirements for a detection system is low load. The term "loading" refers to the inherent (and unavoidable) capacitive effects in any probe. The ideal situation is to minimize the impact of the probe itself on the observed signal. The load index is expressed in picofarads (pf), and this index should be as low as possible. The P6516 probe has a loading of only 3 pf, thus minimizing the impact on signal edges and transients. It should be noted that the probe loading provided by other similar solutions is around 12 pf, which increases the probability of the probe adversely affecting the signal.
From a mechanical perspective, detection requirements vary depending on the service application. Across the board, modern embedded systems feature densely packed circuit boards, and test points can be difficult to access. The P6516 probe offers four digital probe connection methods: a "grab" tip, a flush-mount adapter that connects to a square pin header, an oscilloscope-like handheld tip, and a high-density Mictor splice adapter. These connection methods satisfy both the need for "browsing" between circuit board lands and the need for plug-in connections used in long-term measurements.
