3.9.1. - Scan Miscellany
resume # Restart an aborted scan setscans # Set scan-mode options
If a scan is halted by typing the interrupt character (
^C),
or because of some other error such as hitting a motor limit,
you can normally restart
the scan by typing
resume.
You must not have changed the value of any of the internal scan
variables in the meantime.
If you use
resume to continue a relative position scan, such as
lup or
dscan, the scanned motors will not be returned to the center point when
the scan ends, as they otherwise would be.
You also have the option to control how the scan data is displayed on the screen as it is taken. An option to the
setscans
macro allows the motor positions and scalers contents
to be displayed while they are changing during a scan.
The rate of
updates is set by the
UPDATE
global variable, just as with the
umv
and
uct
macros.
An option to the
setplot
macro, presented earlier,
allows real-time plots of the data points to be displayed
as they are measured.
Another option selected in the
setscans macro lets you choose whether to do prescan motor limit
checks with reciprocal space scans.
The purpose of these checks is to avoid
running into a software motor limit
in the middle of a scan.
For regular motor scans, the limit checks are done only at
the scan endpoints.
For
reciprocal space scans, the motor positions do not
necessarily change monotonically and so
the motor limits must be checked at
each scan point.
Since this checking requires a time-consuming loop at the macro level,
you may choose to disable the feature if you are confident your
reciprocal space
scans will not send a motor outside the ranges
defined by software limits.