innomar SES smart - External Trigger - What to Keep in Mind; Alternating Trigger

80 User’s Manual Innomar SES Parametric Sub-bottom Profilers
80 Innomar Technologie GmbH (2020-09)
It is possible to combine both features of
the SES advanced trigger as shown in the
figure.
In this case the delay is applied before the
burst starts. To avoid discarded trigger
events, the delay and the number of
pings specified have to fit between two
(external) trigger events, see above.
If external trigger events are discarded due to high delay values or too many pings required per
burst, the trigger information “EXT” in the SESWIN status bar starts to flash yellow.
The maximum number of pings

within one
burst (avoiding lost trigger events) is:

=
󰇿
(

.


−

−
1

)



󰈀
All values (trigger period, delay) are time values. Note the fixed delay of 1 ms. Only the integer
part of the calculated result is used (decimals cut off, not rounded).
5.2.5 External Trigger – What to keep in mind
 The external trigger signal should be TTL or RS232 compatible pulses (max. ±15 V).
 If no appropriate trigger signal is fed to the SES 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 SES 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
SES system runs as slave (External Trigger). These transmission modes are for internal
triggering only.
5.3 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 re-
gime as described below.
“Sync IN”
“Sync OUT”