Frequently Asked Questions
What is the benefit of real-time sample compression?
Real-time sample compression or "transitional sampling" allows the LogicPort to utilize its sample buffer much more efficiently. The data is first sampled, then compressed in real-time using a lossless compression algorithm, then written to the sample buffer. The sampled data remains compressed until the software expands it back to its uncompressed form for display.

This entire process is transparent to the user and has zero impact on measurement accuracy, yet allows the LogicPort to pack much more data into its sample buffer. Compression is particularly effective for high-resolution capture of high-speed bursts separated by long periods of low or slow signal activity. That's because during periods when signals have little activity, the LogicPort can continue to sample at high speeds without  filling its sample buffer with thousands of copies of identical data. Only meaningful data is stored in the buffer - memory addresses are not incremented simply to mark time.

The degree of compression varies depending upon the nature of the data, but typically ranges from significant to dramatic. Our proprietary compression algorithm insures that the LogicPort's compression feature never imposes a performance penalty, regardless of signal activity or speed. As a result, the LogicPort enjoys a significant advantage over traditional transitional sampling systems which simply assign half of all available memory locations as storage for time stamps (thereby reducing the effective buffer depth by half for very active signals). To see the LogicPort's sample compression in action take a look at the screenshots, or download the free software and explore the sample projects which are included. As you'll see, it’s not uncommon to collect many times the size of the sample buffer.

How many full-speed channels does the LogicPort support?
The LogicPort will simultaneously sample all 34 channels with full buffer depth at 500MHz in timing mode, 200MHz in state mode. This is in direct contrast with competing products which sample at full speed on only a fraction of their available channels, or with only a fraction of their marketed buffer depth. When sampling in state-mode, one channel is used as a state-clock input allowing the remaining 33 channels to be sampled at the state-clock rate.
Could I sample at 500MHz using an old 400MHz CPU and USB 1.1 port?
Yes! The speed of the PC's CPU and USB port have no relation to the LogicPort's sample rate. The LogicPort can acquire data at up to
17 gigabits per second (34 x 500MHz). This is much faster than any USB interface (even USB 3.0) can transfer data. To achieve these rates, the LogicPort hardware first acquires data in its internal high-speed memory at the chosen sample rate, then stops sampling and transfers data to the PC at a slower rate which USB can handle. Once the transfer is completed, the LogicPort hardware begins a new acquisition while the LogicPort software processes and displays the most recently acquired data. This process is virtually identical to what occurs in a stand-alone logic analyzer. The acquisition and display functions are simply implemented in separate enclosures. The speed of the PC's CPU only effects how fast the software can process newly acquired data for display. Running the LogicPort on a slow PC will reduce the number of times the display is refreshed each second, but the sample rate during acquisition will not be affected. When running on any modern PC the displayed data can be refreshed 15-25 times per second, approximating a real-time display similar to that of an oscilloscope.
Can I use the LogicPort side-by-side with other development tools?
Yes. The LogicPort does not "take over" your PC, and doesn't require 100% of the available CPU or USB resources. It will function normally along side other development tools and Windows applications.
How does the LogicPort connect to my circuit?
Each lead of the color-coded input probe supplied with the LogicPort has a female contact compatible with standard 0.025-0.030” round or square pins. Typically these leads are connected directly to the headers present on many circuit boards. The probe includes four ground leads for optimal high-speed sampling.

The LogicPort probe contacts will also connect directly to grabbers such as the EZ-Hook XKM, and Pomona 5360. These grabbers have 0.025” pins designed for this purpose. EZ-Hook XKM grabbers are identical to those supplied by Agilent (except for color and logo), and are available in our online store. Pomona 5360 grabbers are available from Newark Electronics and others.

Another option is to connect the probe leads directly to PLCC clips such as the 3M 923675-84 and DIP-clips such as the 3M 923690-40. These clips are available from Digi-Key and others, and allow direct connection to PLCC and DIP IC packages.

The LogicPort input connector is a standard 40 pin IDC compatible header. You can use inexpensive IDC connectors and ribbon cable to connect directly to a header on your circuit board, or to create your own custom test leads. The 40 pin cables used with IDE hard drives make a good starting point for custom test leads (be sure to keep them as short as possible).

Is there a Mictor adaptor available for the LogicPort?
Yes. We offer a 38 pin Mictor adapter which has pin and channel assignments directly compatible with those used by Agilent and Tektronix. Our adapter has a 38 pin Mictor plug which mates with Mictor receptacles such as the AMP 5767096-1 and 2-5767004-2. Mictors offer convenient, mechanically secure, high-performance connectivity to target systems. Please contact Intronix sales for purchase information.
Can I export acquired data to another program?
Yes. The sampled data is stored in ASCII format, as comma-delimited values. You can import this data directly into programs like Microsoft Excel.
Can I run the LogicPort from a bus powered USB hub?
Yes. As long as the current required by the hub plus all connected devices does not exceed 500 milliamps (per USB specification). The LogicPort’s low power consumption makes this condition easy to meet.
Is it possible to use multiple LogicPorts for more channels?
We do have customers using them this way, however It is only practical to use multiple units in state mode, and only if your circuit can provide a common clock and trigger signal to all units. Cross triggering between units is not possible. Each unit must have a separate instance of the software installed and running. Please contact support for more information if you plan to use multiple units.
Have a question not answered here?
Ask us by emailing support@pctestinstruments.com.
 
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