External Trigger Input; Triggered Burst - Metrix GX1010 Notice De Fonctionnement

4.4.2. External Trigger Input

External trigger or gate signals are applied to the front panel EXT TRIG input which has a
TTL level (1·5V) threshold. In Triggered Burst mode the input is edge sensitive; the rising
edge of each external trigger initiates the specified burst. In Gated mode the input is level
sensitive; the output of the main generator is on whilst the gate signal is high (>1·5V).
The minimum pulse width that can be used with the EXT TRIG input is 50ns and the
maximum repetition rate is 1MHz. The maximum signal level that can be applied without
damage is ±10V.

4.4.3. Triggered Burst

Triggered Burst mode is turned on and off with alternate presses of the TRIG key; the lamp
beside the key lights when triggered mode is on. The triggered mode parameters (trigger
source, internal trigger generator, burst count and start/stop phase) are all set from the
trigger edit menu which is selected by pressing the blue EDIT key followed by the TRIG
key. When trigger edit is selected the lamp beside the TRIG key flashes to show edit mode
regardless of whether triggered burst operation is currently selected to be on or off.
4.4.3.1. Trigger Source
With the edit cursor in the SOURCE field of the trigger edit menu, the DIGIT keys or rotary
control can be used to select EXTernal, MAN/REMOTE, or internal Trigger GENerator as
the trigger source.
With the source set to EXTernal, the specified burst is triggered by the rising edge of a
trigger signal applied to the EXT TRIG input, see External Trigger Input section. With the
source set to MAN/REMOTE, a burst can be initiated by pressing the front panel
MAN/SYNC key or by the appropriate command via the RS232 or GPIB interfaces.
With the source set to TGEN, the burst is triggered internally as described in the Internal
Trigger Generator section. The period of the internal generator is set in the TGEN field on
the second line of the edit menu. With the cursor in the numeric field the DIGIT keys will
move the cursor within the field and the rotary control will change the value in increments
determined by the cursor position; with the cursor in the units field the DIGIT keys or rotary
control will change the value in decade increments. Direct keyboard entries (number plus
units) will be accepted with the cursor in either field. Beside the generator period value the
equivalent frequency is shown; this is for information only and is not an editable field.
Because the internal trigger generator can be used by the trigger, gate, FSK and AM
functions, and can be set from their respective edit menus, an information field is displayed
in brackets beside TGEN when this is selected as the source. This field will show [FREE]
when TGEN is not used elsewhere, or any of the letters [G,F,A,T] to indicate that the
generator is currently set as the source on the GATE, FSK, AM, or TRIG menus
respectively, in addition to the menu currently displayed.
4.4.3.2. Burst Count
The number of complete cycles in each burst following the trigger is set with the edit cursor
in the BURST COUNT field. Entries can be made direct from the keyboard or by rotary
control; the burst range is 1 to 1023 with a resolution of 1 cycle or 0·5 to 511·5 with a
resolution of 0·5 cycles. The first cycle starts, and the last cycle stops, at the phase set in
the PHASE field.
GX1010
SOURCE=EXT
TGEN=1·00ms 1·000kHz
BURST COUNT= 0001
PHASE=+000° (+000°)
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