User’s Manual Innomar SES Parametric Sub-bottom Profilers 81
Innomar Technologie GmbH (2020-09) 81
“Alternating Trigger” is mainly intended for use at shallow water where high ping rates are
achieved by the Innomar SBP and a system with much lower ping rate (like a sparker) shall be
triggered.
For this mode the user has to set three parameters:
time frame of external device (either as absolute value or as percentage of range),
number of INNOMAR SBP pings (“internal pings”),
number of external pings.
The external device that has to be triggered by the INNOMAR system should run in a fixed regime
(fixed range). The resulting ping rate has to be determined and the time for one cycle has to be
set as “time frame of external device” within the “Alternating trigger” settings.
These settings and their effect on the trigger regime are illustrated in the figures below. These
examples assume the same ping rate of 25 PPS (40 µs ping interval) for both, the INNOMAR SBP
and the external device.
Both systems pinging alternating. The INNOMAR
SBP pings once and generates an external trig-
ger pulse after finishing data acquisition. Then
waits for the specified time after the external trig-
ger pulse before starting the new transmission.
The INNOMAR SBP transmits twice per transmit
cycle. Otherwise the same as above.
The INNOMAR SBP transmits once and generates
two external trigger pulses (with specified delay)
before starting pinging itself.
“Alternating Trigger” can also be used for asuring a fixed ping rate and synchronisation with other
acoustic systems. An example is given in section 6.7 on page 103.
Time for external deviceSBP Ping
Trigger Pulse at "Sync OUT"
Time for external deviceSBP Ping
Trigger Pulse at "Sync OUT"
Trigger Pulse at "Sync OUT"
SBP Ping Time for external device
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