innomar SBP smart - Alternating Trigger

86 User’s Manual INNOMAR Parametric Sub-Bottom Profilers / SESWIN
86 Innomar Technologie GmbH (2023-01)
 If no appropriate trigger signal is fed to the system, no sound ping is generated and no data
is collected. The SESWIN echo screen will not scroll.
 The INNOMAR SBP is triggered with the rising edge (low to high transition) of the trigger
pulse.
 There is a time delay between trigger event and transmitted sound ping of ca. 1 ms.
 When using “ping rate increase”, bursts of sound pings are transmitted. The time between
two pings in the burst equals the ping rate that would be used at internal synchronisation.
 The total time required for all the pings per burst (“Number of pings” * ping period) + “Delay”
has to be smaller than the external trigger period. Otherwise every second trigger event will
be discarded.
!
Older INNOMAR SBPs may have different behaviour regarding external synchronisation!
Please note that “Deep Sea Pulse Mode” and “Deep Sea Burst Mode” will not work if the
INNOMAR SBP runs as slave (External Trigger). These transmission modes are for
internal triggering only.
6.3 Alternating Trigger
There is a third basic trigger mode available, called “Alternating Trigger”. In this mode the
INNOMAR SBP is running as master device triggering other acoustic systems, similar to “Internal
Trigger” mode. But with “Alternating Trigger” the trigger pulse at the “Sync OUT” connector is not
generated when the INNOMAR SBP pings and there are some parameters to tune the trigger
regime as described below.
“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.