17-2000 C
2020-09-17
22(50)
ADQ8-8C Manual
17-2000 C 2020-09-17
22(50)
4.8.2
External trigger SYNC connector
The block diagram for the SYNC input is shown in
and related parameters are listed in
. The user can control the SYNC function for adapting it to the system in the following ways:
•
The input impedance can be set in 50
(default) or high impedance mode, see
•
Set the trigger edge to rising or falling to adjust to the polarity of the trigger signal.
4.8.3
Driving the external TRIG/SYNC signal by controlling input impedance
The TRIG/SYNC input impedance is by default 50
. The trigger is optimized for systems where the
trigger source output impedance is 50
and the cables has a characteristic impedance of 50
. This
setup results in an optimal high-frequency response and low reflections, which is important for precise
timing.
#
DESCRIPTION
USER COMMAND
REF
a
The input is available on an SMA connector on the front panel.
b
The input impedance can be set as 50
(default) or high
impedance 500
.
SetTriggerInputImpedance
c
The trigger threshold is 0.5 V (default) and user-controlled.
SetTriggerThresholdVoltage
d
High speed comparator.
e
Select rising or falling edge.
SetExternTrigEdge
Figure 12: External trigger on front panel.
#
DESCRIPTION
USER COMMAND
REF
a
The input is available on an SMA connector on the front panel.
b
The input impedance can be set as 50 ohm (default) or high
impedance.
SetTriggerInputImpedance
c
The trigger threshold is fixed at 1.5 V.
d
High speed comparator.
e
Select rising or falling edge.
SetExternTrigEdge
Figure 13: Using SYNC as trigger input.
*+,
(-
*#./
01
01
01
01
01
+-
#
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(,
-./
01
01
01
01
01
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