Avtech AVR-E3A-B, Instructions Manual

Page: 20 / 40

The next figure illustrates the relationship between the signal when an external TTL-
level trigger is used:
Figure C
As before, if the delay is negative, the order of the SYNC and OUT pulses is reversed.
In general, the delay, pulse width, and frequency (when in the internal mode), of the
OUT pulse can be varied with front panel controls or via the GPIB or RS-232 computer
interfaces.
TRIGGER MODES
This instrument has four trigger modes:

Internal Trigger: the instrument controls the trigger frequency, and generates the
clock internally.

External Trigger: the instrument is triggered by an external TTL-level clock on the
back-panel TRIG connector.

Manual Trigger: the instrument is triggered by the front-panel “SINGLE PULSE”
pushbutton.

Hold Trigger: the instrument is set to not trigger at all.
These modes can be selected using the front panel trigger menu, or by using the
appropriate programming commands. (See the “Programming Manual for -B
Instruments” for more details.)
20
SYNC OUT
100 ns, FIXED
MAIN OUTPUT
PULSE WIDTH DELAY > 0
AMPLITUDE,
VARIABLE
3V, FIXED
> 50 ns
TTL LEVELS
(0V and 3V-5V)
TRIG
(external input)
PROPAGATION DELAY (FIXED)