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The two trigger modes are:
Software Triggering: A trigger is initiated internal to the Spectrometer with a command from Ocean Insight approved software. The integration period is set by
software configuration.
External Edge Triggering: A trigger is initiated by the rising edge of the external trigger signal on the auxiliary connector. The integration period is set by soft-
ware configuration.
Software Trigger
The default triggering mode is for a software trigger. A Software Trigger may be initiated by either OceanView, OmniDriver, or OceanDirect software. Once a
command is sent to the Spectrometer, an internal trigger is generated, which begins an acquisition cycle.
If a start time of T
0
is defined as the moment a software command requests an acquisition, then there is a latency time of t
PROC
, which is the Software Com-
mand Processing time from T
0
to when the integration cycle starts. This latency varies from computer system to computer system.
The integration delay, t
INTDLY
, starts after t
PROC
and ends before the start of integration time, t
INTEG
. The integration delay is the sum of the user defined acquisition
delay, t
ACQDLY
and t
BUSY1
.
The integration period, t
INTEG
, is user defined but has a minimum value of 1560 µs.
Following the integration period, the detector is busy to finish the acquisition cycle and that time is t
BUSY2
. After this time, the detector is ready for another trigger.
The equation for the integration delay can be written as
t
INTDLY
= t
ACQDLY
+ t
BUSY1
where t
BUSY1
= 1560 µs
The single strobe is active at the end of t
PROC
and with the start of the acquisition delay, t
ACQDLY
. The single strobe itself can have a delay defined as t
SSDLY
. The
single strobe is a single pulse that goes high at the end of t
SSDLY
and stays high for a time of t
SSH
. The values for the single strobe delay and pulse high time are
set by the user in OceanView or OceanDirect software.
The continuous strobe signal is a series of pulses with a user specified period that starts with the beginning of the integration time, t
INTEG
. The pulses have a
50% duty cycle and only full periods are exercised during an integration period. If a subsequent continuous strobe period cannot be completed before the end
of the integration cycle, the continuous strobe signal is turned off and set to 0.
