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Operation of Complex Multi-card scanning

Hello I am having an issue with doing a more complicated scanning procedure with multiple 2535 switch matrix cards.

 

At present, the cards only produce a scanadvance event when a switch has latched, not during skip actions or disconnect actions. For the case where only one card acts at a time, this is not a problem, and NI documents a case for multi card scanning where all the cards are connected: http://zone.ni.com/reference/en-XX/help/375472H-01/switch/handshakingg_multiple/#uiptl  <- in this example, all of the cards have the same output trigger line, so if only one card triggers it is ok.

 

Unfortunately, for more complex scan configurations, where, say two cards may switch at the same time and one is dormant this is problematic since, to avoid race conditions, it is advantageous to implement hand shaking where card0 triggers card1 which triggers card2 which would trigger the dmm or smu. Unfortunately, since for ignore operations, the cards do not propogate the trigger, this operation does not work. The only work around that I have been able to generate is to "wiggle"  a random connection by disabling and enabling it so that the card is always in a state of action. This appears to eliminate the problem, but reduces the  number of available rows/columns.

 

Is there a more effective way to force an ignore operation, such as " ; ; ; " in the scanlist to propagate the trigger? Could this be done with trigger routing? or a change in settings? 

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