Spyder3 GigE Vision SG-14 Monochrome Cameras User’s Manual
33
Teledyne DALSA
03-032-20123-01
Timing: Exposure and Synchronization
Im age exp osu res are initiated by an event. The trigger event is either the cam era's p rogram m able internal
clock u sed in free ru nning m od e, an external inp u t u sed for synchronizing exp osu res to external triggers,
or a p rogram m ed fu nction call m essage by the controlling com p u ter.
Trigger com m and s are available as m em bers of the Sen sor Control set.
GigE Vision Input Controls
Line Trigger
Trigger Mod e
The state of the line trigger. If OFF, then the line trigger is
internally generated . If ON , then triggered by an external
signal.
Trigger Sou rce
The external sou rce that cau ses a line trigger. The line
trigger is from the GPIO_PIN 0. This featu re is available
only w hen Line Trigger Mod e is set to ON .
Trigger Activation
Determ ines the typ e of signal (high or low ) that w ill cau se
a line trigger. Line Trigger Mod e m u st be ON .
External Line Trigger Frequ ency
Read s the external line trigger frequ ency. N OTE: The
cam era cannot d etect frequ ency less than 5 H z and w ill
d isp lay 1 if it cannot d etect a signal. This featu r e is
available w hen the Line Trigger Mod e is set o ON and
Sensor Direction Control is set to External.
The three trigger m od es are d escribed here:
Free running (trigger disabled)
The cam era free-ru nning m od e has a p rogram m able internal tim er for line rate and a p rogram m able
exp osu re p eriod . Line rate is 0.1 fp s to th e m axim u m su p p orted by the sensor. Exp osu res range from the
sensor m inim u m to a m axim u m also d ep end ent on the cu rrent line rate. This alw ays u ses Synchronou s
m od e w here exp osu re is aligned to the sensor horizontal line tim ing.
External trigger
Exp osu res are controlled by an external trigger signal. External signals are isolated by an op to-cou p ler
inp u t w ith a tim e p rogram m able d ebou nce circu it. The follow ing section p rovid es inform ation on
external trigger tim ing.
Software trigger
An exp osu re trigger is sent as a control com m and via the netw ork connection. Softw are triggers can not
be consid ered tim e accu rate d u e to netw ork latency and sequ ential com m and jitter. Bu t a softw are trigger
is m ore resp onsive than calling a single-line acqu isition (Snap com m and ) since the latter m u st valid ate
the acqu isition p aram eters and m od ify on -board bu ffer allocation if the bu ffer size has changed since the
last acqu isition.
