**ShowPlay Reference Manual, Chapter 3 (ControlVariables): trig_flag**

===== Trig_flag -- Trigger options =====
The TRIG_FLAG variable is used to allow an external signal to trigger the start of a paradigm. 

Values for TRIG_FLAG are:
   0 - do not look for external trigger
   1 - start on external trigger or manual trigger
   2 - record external trigger events for every T_R interval
   4 - start on manual trigger only
   8 - quick start -- ignore DISDAQS
  16 - immediate start -- ignore 1 & 4 flags
  32 - immediate start -- skip "Ready to Scan" alert box
TRIG_FLAG is used in conjunction with [[jvs:cigal:showplay:manual:chapter3:trigtype|TRIGTYPE]], which indicates which external signal is to be used for the trigger. Other parameters ([[jvs:cigal:showplay:manual:chapter3:atrig_chan|ATRIG_CHAN]],[[jvs:cigal:showplay:manual:chapter3:atrig_val|ATRIG_VAL]], [[jvs:cigal:showplay:manual:chapter3:dstartmask|DSTARTMASK]]) are also used to specify exactly what aspect of the external signal qualifies as a trigger.

**See Also:**\\
[[jvs:cigal:showplay:manual:chapter3:trigtype|Trigtype]],
[[jvs:cigal:showplay:manual:chapter3:disdaqs|Disdaqs]],
[[jvs:cigal:showplay:manual:chapter3:atrig_chan|Atrig_chan]],
[[jvs:cigal:showplay:manual:chapter3:atrig_val|Atrig_val]],
[[jvs:cigal:showplay:manual:chapter3:dstartmask|Dstartmask]]\\
[[jvs:cigal|CIGAL Home]], 
[[jvs:cigal:manual|CIGAL Manual]], 
[[jvs:cigal:showplay|ShowPlay Home]], 
[[jvs:cigal:showplay:manual|ShowPlay Manual]], 
[[jvs:cigal:showplay:manual:chapter3|InputParameters List]], 
[[jvs:cigal:showplay:manual:help|Manual Help]]