Strategic Test's System Star Hub for the UltraFast oscilloscope/digitiser allows up to 270 cards in multiple PCs to be synchronised allowing systems with up to 4336 analogue or 8672 digital channels
The System Star Hub distributes a common sampling clock and trigger bus across up to 17 PCs.
The System Star Hub Master option is installed on one UltraFast card in the main PC and System Star Hub Slave options are installed on one card in the remaining PCs.
Master and slaves are then cabled together externally.
The maximum distance between each pair of PC's is two metres.
Different types of cards can be used together to create systems with oscilloscopes, arbitrary waveform generators, high-speed digital I/O or digital pattern generators.
Not all cards have to use the same sampling rate, as the master sampling clock can be divided uniquely on each card.
"The System Star Hub allows users to double the number of cards that can be synchronized together as compared to other competitive offerings," comments Bob Giblett, president of Strategic Test.
"This new architecture now easily enables applications such as measuring fatigue and structural response on aircraft and bridges, or wind tunnel measurement systems".
The System Star Hub also has the advantage of using the combined PCI bus bandwidths across all PCs to achieve a much higher streaming rate throughout the system.
When one PC is used, the PCI bus has a maximum continuous transfer rate of 100MBytes per second.
This bandwidth is shared by all cards installed and has the effect of limiting the maximum sampling rates of the cards.
For example, when using eight-bit resolution the maximum sampling rate of ten channels when streaming would be 100MSamples per second, or 10MSamples per second per channel.
However, if ten cards each with single channel were distributed in ten PC's, each channel could reliably stream up to 100MSamples per second.
Maximum sampling rates are not limited if the signals are recorded to card memory without streaming.
However, the time to offload the data at the end of the measurement is extended due to the same bandwidth limitation issues.
The System Star Hub performance will increase in the future.
The UltraFast PCI cards are also compatible with the PCI-X (66MHz PCI bus) that has a maximum continuous transfer rate of 225MBytes per second (2.25 times faster than 33MHz PCI).
Unfortunately, no motherboards exist today with more than a few PCI-X slots.
As these do become available, the streaming performance across a System Star Hub configuration will increase.
The price of the Star Hub option to synchronize up to five cards in a single PC is US$490 and $990 for up to 16 cards.
To synchronise multiple PCs, a System Star Hub Master option is needed for the first PC and is priced at $2800.
The additional PC's are then each equipped with System Star Hub Slave that are priced at $590 for up to five cards or $990 for up to 16 cards.
