C9300-201 Ver.1.2
18H
AMAMATSU PHOTONICS K.K.
9-3-4-2 External control mode [AMD E]
The external trigger pulse is input via the timing I/O connector on the rear panel and the polarity
is selected from “N” (negative: Low-level active) or “P” (positive: High-level active). The external
trigger pulse should be TTL level and the minimum active period is 1 µs and the repeat cycle
must match the selected mode.
Note
•
Images are not output correctly if the pulse input is shorter than 1 µs.
The following text describes the external control mode with the external trigger pulse polarity
set to “N” (negative). If “P” (positive) is selected, the rise and fall of each pulse is reversed
(inverted), with the LO interval becoming the HI interval. Descriptions enclosed in brackets ({ })
indicate cases where “P” (positive) is selected.
(1) Exposure time setting: Internal / Electronic Shutter [EMD E, EST n]
Exposure begins within 2
μ
s from the fall {rise} of the external trigger pulse, the
exposure is made using the time set with the EST n command, and readout follows.
After readout, the system waits for the external trigger pulse to fall {rise} again. The
exposure time is set with the EST n command. This setting is made in units of one
horizontal scan cycle. The repeat cycle is controlled by the external control pulse's
repeat cycle, but the minimum cycle is calculated as shown below. Set the external
control pulse's repeat cycle so that it is longer than the minimum cycle.
Minimum repetition time = readout time + set exposure time
[Exposure timing]
CCD exposure
Readout signal
from CCD chip
Digital data
output
External trigger
pulse
Electrical
shutter signal
min. 1 µs
Readout period
Exposure time =
EST n
max. 2 µs
