Specifications

Setting up the Trigger System
Arm and Trigger
Sources
Figure 3-7 shows the trigger and arm model for the VT1419A. Note that when the
Trigger Source selected is TIMer (the default), the remaining sources become Arm
Sources. Using ARM:SOUR allows an event to be specified that must occur in
order to start the Trigger Timer. The default Arm source is IMMediate (always
armed).
Selecting the
Trigger Source
In order to start an algorithm execution cycle, a trigger event must occur. The
source of this event is selected with the TRIGger:SOURce <source> command. The
following table explains the possible choices for <source>.
Parameter Value
Source of Trigger (after INITiate:¼ command)
BUS TRIGger[:IMMediate], *TRG, GET (for GPIB)
EXTernal “TRG” signal input on terminal module
HOLD TRIGger[:IMMediate]
IMMediate The trigger signal is always true (scan starts when an
INITiate:¼ command is received).
SCP SCP Trigger Bus (future SCP Breadboard)
TIMer The internal trigger interval timer (must set Arm source)
TTLTrg<n> The VXIbus TTLTRG lines (n=0 through 7)
Programming the VT1419A Multifunction
Plus
Setting up the Trigger System
Chapter 3 77
BUS
ARM/TRIGger Sources
ARM Source Selector
Trigger Source Selector
EXTernal
Trigger
Timer
Trigger
Enable
TIMer
TRIGger:TIMer <interval>
TRIGger:SOURce <source>
TRIGger:COUNt <count>
Internal
Trigger Signal
Trigger Counter
ARM:SOURce <source>
HOLD
IMMediate
TTLTrg< >n
SCP Trig
Only while
INIT:CONT is ON
&
TRIG:SOUR is IMM
Figure 3-7: Logical Arm and Trigger Model
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com