As you already have seen in the example above, an
consists of one or more sections. There are up to 6 different types of
sections. These are specified by the following section keywords:
DEVICES VARIABLES ASSIGNMENTS PHASES PREPARATIONS EXPERIMENT
Please note that the section keywords always have to be followed by a
The first and last two sections have already been used in our example
DEVICES section consists simply of a list of all the
devices that will be used in the experiment (or at least the ones that
are going to be controlled by the computer).
VARIABLES section for declaring and initializing variables
has also already been discussed in the example.
Because pulses play an important role in modern EPR experiments lots of
elements for handling pulses and the pulsers that creates them are built
fsc2. Thus, there are even two special sections,
PHASES, exclusively devoted to the pulser
setup. The basic setup of the pulser (e.g. setting the timebase and
trigger mode as well as setting up the pulser channels) is done in the
ASSIGNMENTS section while the
PHASES section is all about
phase-cycling - here you may have to define the phase sequences to be
used in the experiment as well as the way the resulting echos will be
added up. Because this is a rather extensive subject (and because of the
different ways pulsers are used in the supported spectrometers) an
in-depth discussion of both these sections is part of a whole chapter
(see Using Pulsers).
As you already have seen, the
PREPARATIONS section is for setting
up all the other devices and initializing graphics - basically the
things you would do before actually starting an experiment. This is also
the section where pulses are going to be defined. Again, for more
details about this last topic see the chapter about pulse generators and
pulses (see Using Pulsers).
Finally, there is the
EXPERIMENT section. As you already have
seen this section usually consists of one or more loops, possibly nested,
where data are acquired and stored.
While the sections of an
EDL script don't have to appear in the
sequence in which they are listed above it is probably best not to
experiment too much with this. In any case, if it exists the
EXPERIMENT section must always be the last one.
All the section keywords can be abbreviated, here's the complete list of valid section keywords:
Beside these sections there is a label that looks very similar to a section label, the
label (which also must be followed by a colon,
:). It can only
appear within the
EXPERIMENT section. The
ON_STOP label can
be used to guarantee that a certain part of the
section is going to be executed even after the user hit the
button. It will probably contain code that stores previously unsaved
data and does other things that are necessary before the experiment
really is finished. When
fsc2 executes the code following the
ON_STOP label it won't react to the
Stop button anymore.
This document was generated by Jens Thoms Toerring on October, 4 2009 using texi2html 1.78.