...
Excerpt |
---|
|
...
ScanImage |
...
utilizes |
...
various |
...
data |
...
acquisitions |
...
subsystems |
...
(each |
...
bank |
...
of |
...
Analog |
...
Input |
...
and |
...
Output |
...
channels |
...
per |
...
board |
...
comprises |
...
a |
...
subsystem) |
...
during |
...
its |
...
operation. |
...
The |
...
start |
...
time(s) |
...
of |
...
the |
...
data |
...
streams |
...
on |
...
each |
...
of |
...
these |
...
subsystems |
...
must |
...
be |
...
synchronized |
...
for |
...
each |
...
acquisition. |
...
This |
...
requires |
...
that |
...
each |
...
of |
...
the |
...
subsystems |
...
'listen' |
...
for |
...
a |
...
common |
...
Start |
...
Trigger |
...
signal |
...
(i.e. |
...
a |
...
digital |
...
rising/falling |
...
edge) |
...
which |
...
initiates |
...
the |
...
acquisition/generation. |
...
To |
...
accomplish |
...
this, |
...
ScanImage |
...
identifies |
...
a |
...
...
...
'programmable |
...
function |
...
interface' |
...
(PFI) |
...
terminal |
...
(e.g. |
...
PFI0, |
...
PFI1, |
...
etc) |
...
which |
...
can |
...
serve |
...
as |
...
a |
...
'listener' |
...
for |
...
a |
...
Start |
...
Trigger |
...
input |
...
signal. |
...
|
...
if |
...
PFI0 |
...
is |
...
used, |
...
it |
...
must |
...
be |
...
used/connected |
...
on |
...
all |
...
boards). |
...
Start |
...
Triggering |
...
Modes |
...
Every |
...
ScanImage |
...
acquisition |
...
requires |
...
a |
...
Start |
...
Trigger |
...
– this |
...
can |
...
be |
...
either |
...
Internal |
...
or |
...
External |
...
. |
...
|
Trigger Time Logging
The time at which the Start Trigger arrives, initiating an acquisition, is stored as part of the image file header, to aid with analysis, e.g. for aligning image data to separately obtained physiology/stimulus/behavior data. The following header fields are stored:
- : Represents the trigger time of the saved GRAB acquisition or LOOP Repeat as accurately as possible in Matlab date string format.
- : Represents the trigger time of the saved GRAB acquisition or LOOP Repeat in less-accurate manner, for backward-compatibility, as a Matlab date string format.