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(c) Spectrum Instrumentation GmbH
Star-Hub introduction
Option Star-Hub
Option Star-Hub
Star-Hub introduction
The purpose of the Star-Hub is to extend the number of channels available for acquisition or generation by interconnecting multiple cards and
running them simultaneously.
The Star-Hub option allows to synchronize several M2p cards that are mounted within one host system (PC) and is part of the digitizerNETBOX
and generatorNETBOX products, that include more than one digitizer/generator module.
Two different sized Star-Hub versions are available: a small version with 6 connectors (options SH6ex or SH6tm) for synchronizing up to six
cards and a bigger version with 16 connectors (options SH16ex or SH16tm) for synchronizing up to sixteen cards.
The M2p Star-Hub allows synchronizing cards of the same family as well as different families of the M2p
series with each other
Both sizes versions are implemented as either a piggy-back module that is mounted on top of one of the cards (options SH6tm or SH16tm),
or as an extension (SH6ex or SH16ex). For details on how to install several cards including the one carrying the Star-Hub module, please
refer to the section on hardware installation.
Either which of the available Star-Hub options is used, there will be no phase delay between the sampling clocks of the synchronized cards
and either no delay between the trigger events. The card holding the Star-Hub is automatically also the clock master. Any one of the synchro
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nized cards can be part of the trigger generation.
Star-Hub trigger engine
The trigger bus between an M2p card and the Star-Hub option consists of several lines. Some of them send the trigger information from the
card’s trigger engine to the Star-Hub and some receive the resulting trigger from the Star-Hub. All trigger events from the different cards con
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nected can be combined logically by either OR or a logical AND within the Star-Hub.
While the returned trigger is identical for all synchronized cards, the sent out trigger of every single card depends on their respective trigger
settings.
Star-Hub clock engine
The card holding the Star-Hub is the clock master for the com
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plete system. If you need to feed in an external clock to a syn
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chronized system the clock has to be connected to the master
card. Slave cards cannot generate a Star-Hub system clock.
As shown in the drawing on the right, the clock master can use
either its on-board reference, an external reference or directly
distribute the external fed in clock input to be broadcast to all
other cards.
All cards including the clock master itself receive the distribut
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ed clock with equal phase information. This makes sure that
there is no phase delay between the cards.
Software Interface
The software interface is similar to the card software interface that is explained earlier in this manual. The same functions and some of the
registers are used with the Star-Hub. The Star-Hub is accessed using its own handle which has some extra commands for synchronization
setup. All card functions are programmed directly on card as before. There are only a few commands that need to be programmed directly
to the Star-Hub for synchronization.
The software interface as well as the hardware supports multiple Star-Hubs in one system. Each set of cards connected by a Star-Hub then
runs totally independent. It is also possible to mix cards that are connected with the Star-Hub with other cards that run independent in one
system.
Star-Hub Initialization
The interconnection between the Star-Hubs is probed at driver load time and does not need to be programmed separately. Instead the cards
can be accessed using a logical index. This card index is only based on the ordering of the cards in the system and is not influenced by the
current cabling. It is even possible to change the cable connections between two system starts without changing the logical card order that
is used for Star-Hub programming.
Image 79: Drawing of star-hub clock engine location and interaction with card clock
Summary of Contents for M2p.59 Series
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