Interface description
NDRA91-92
Manual
Page 44
NADO
5.5
Trigger Port
The trigger port allows two different uses:
1.
Start a single distance measurement DF by an external signal in the form
of a voltage pulse, the delay of the release trigger (trigger delay) and to
triggered edge (trigger level) may be set.
2.
Interconnection of several
NDRA91
:
a)
The first
NDRA91
is working as master in the mode DT or DM; when
the laser impulse is started, a trigger signal is sent simultaneously.
b)
The 2.
NDRA91
and further
NDRA
s working as slaves in mode
DF
(Trigger input). They will start a measurement after the first
NDRA91
.
By a temporal delay between the measurements, which is
adjustable
with the trigger delay, interference between the
devices can be
excluded. The trigger frequency corresponds to the
set frequency MF
of the first
NDRA91
.
Parameter TD:
z = 0 mandatory
x = delay is necessary15; interference between the different
NDRA91
is avoided.
The parameterization of the trigger connection is carried out via the serial
interface. Command TDx_y. (“_“ corresponds to empty space (0x20)) The
trigger function is only active in the measurement mode DF.
Voltage level for the trigger signals:
Low level
0 – 1,5 V
High level
3 – 30 V
Threshold
2.25 V
Hysteresis
0.1 V
15
Depending on the measuring time (see also TD and SA)