Dectris EIGER 2 - EXTE - Externally Enabled Exposure Series

After the detector has been initialized, congured, and armed the acquisition can be triggered by a single
external trigger pulse. The detector starts exposing after the (electrical) trigger signal has been issued. All sub-
sequent frames are internally triggered according to the information previously congured by the frame_time
and count_time parameters. The detector records nimages frames and stays armed until ntrigger are received.
Figure 9.3 depicts an externally triggered series dened by frame_time, count_time and nimages.
Time
frame_time
count_time
nimages
1
2
3
- Enable Out
-
External In
Figure 9.3: Exposure series dened by frame_time, count_time and nimages, triggered by a single external trigger pulse.
Note that the periods are not drawn true to scale.
9.5. EXTE - Externally Enabled Exposure Series
Caution #5
Consult the Technical Specications for details about the required electrical characteristics of
the trigger signal.
The EIGER2 detector systems also support external enabling. In the external enable mode ’exte’ a series of
ntrigger frames can be recorded. The count time as well as the period of individual frames of a series are
dened by the duration of the high state of the external enable signal. In all enable modes the detector con-
guration parameter nimages is implied to be 1. The number of frames in a series therefore is solely based on
the value of the parameter ntriggger.
Information #11
The congured count_time and frame_time should be close to the count time and frame time
of the shortest expected exposure in the congured series. The set count_time will be used
to calculate internal auto-summation conguration values (section 3.2.3). In most situations a
reasonable estimate of these values is sucient.
Example detector conguration for externally enabled exposure series:
detector | cong | trigger_mode {”value”: ”exte”}
detector | cong | nimages {”value”: 1}
detector | cong | ntrigger {”value”: 10}
detector | cong | frame_time {”value”: 1.0} ( see 11)
detector | cong | count_time {”value”: 0.7} ( see 11)
DECTRIS EIGER
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