33
Sequencer
8.6
General Information
8.6.1
A sequencer is used for the automated control of series of images using different sets of
parameters.
m
o
z
n
0
n
1
n
2
n
x-1
A
B
C
The figure above displays the fundamental structure of the sequencer module
.
The
loop counter (m) represents the number of sequence repetitions.
The
repeat counter (n) is used to control the amount of images taken with the respective
sets of parameters. For each set there is a separate n.
The start of the sequencer can be realized directly (free running) or via an external event
(
trigger). The source of the external event (trigger source) must be determined before.
The additional
frame counter (z) is used to create a half-automated sequencer. It is ab
-
solutely independent from the other three counters, and used to determine the number of
frames per external trigger event.
The following timeline displays the temporal course of a sequence with:
n = (A=5), (B=3), (C=2) repetitions per set of parameters
▪
o = 3 sets of parameters (A,B and C)
▪
m = 1 sequence and
▪
z = 2 frames per
▪
trigger
t
n = 1
n = 2
n = 3
n = 4
n = 5
n = 1
n = 2
n = 3
n = 1
n = 2
A
B
C
z = 2
z = 2
z = 2
z = 2
z = 2
◄ Figure 36
Flow chart of
sequencer.
m - number of
sequence repeti-
tions
n - number of set
repetitions
o - number of
sets of parameters
z - number of frames
per trigger
Sequencer Parameter:
The mentioned sets of
parameter include the fol-
lowing:
Exposure time
▪
Gain factor
▪
Repeat counter
▪
IO-Value
▪
◄ Figure 37
Timeline for a single
sequence
