Trigger modes and appendant registers
General Description
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Trigger modes and appendant registers
General Description
The trigger modes of the Spectrum M2i series A/D cards are very extensive and give you the possibility to detect nearly any trigger event,
you can think of.
You can choose between seven external TTL trigger modes and up to 20 internal trigger modes (on analog acquisition cards) including soft-
ware and channel trigger, depending on your type of board. Many of the channel trigger modes can be independently set for each input
channel (on A/D boards only) resulting in a even bigger variety of modes. This chapter is about to explain all of the different trigger modes
and setting up the card’s registers for the desired mode.
Every analog Spectrum board has one dedicated SMB connector mounted in its bracket for feeding in an external trigger signal or generating
a trigger output of an internal trigger event. Due to the fact that only one connector is available for external trigger I/O, it is not possible to
forward the fed in external trigger signal to another board. If this is however necessary, you need to split up the external trigger signal before.
Trigger Engine Overview
To extend trigger facilities of the various trigger
sources/modes further on, the trigger engine of
the Spectrum M2i series allows the logical combi-
nation of different trigger events by an AND-mask
and an OR-mask.
The Enable trigger allows the user to enable or dis-
able all trigger sources (including channel trigger
and external TTL trigger) with a single software
command.
Channel trigger is only available on data acquisi-
tion cards.
When the card is waiting for a trigger event, ei-
ther for a channel trigger or an external trigger,
the force-trigger command allows to force a trig-
ger event with a single software command.
Before the trigger event is finally generated, it is
wired through a programmable trigger delay.
All analog D/A and A/D cards have one external trigger input (External0) and digital i/o cards and pattern generators have one to two
external trigger inouts (External0 and External1). In addition using the option BaseXIO it is possible to have two additional trigger inputs
named XIO0 and XIO1 in the drawing.
Trigger masks
Trigger OR mask
The purpose of this passage is to explain the trigger OR mask (see left figure) and all the appendant software
registers in detail.
The OR mask shown in the overview before as one object, is separated into two parts: a general OR mask for
external TTL trigger and software trigger and a channel OR mask.
