(provided
by Dr. Charles Flagg)
The purpose of the AutoADCP routine is to provide a method
for unattended operation of shipboard ADCPs. The primary
functions include the ability to change the ADCPs configuration
based upon the ship’s location and to assure that
data collection continues by means of a watchdog timer.
An earlier version of the program was developed for RD
Instruments’ DAS 2.48 to operate on ships of opportunity
and was later adopted for use on several research vessels.
With the development of a new generation of ADCPs and
PC operating systems, a new version of AutoADCP was needed
that was compatible with VM-DAS and Windows 95 through
XP.
Unlike the original AutoADCP system that made use of the user-exit capability
of DAS 2.48, the new version is a standalone Visual
Basic program that initiates and controls the operation
of VM-DAS through keyboard emulation. The routine’s
operation is governed by a control file, which defines
the file and directory structure for both AutoADCP and
VM-DAS. Included in the control file is a default options
(*.ini) file used at the startup of the ADCP, a regions
file described below, as well as a history file in which
each action taken by the AutoADCP routine is logged.
An important component of the system identified in
the control file is the regions file which establishes
a set of polygonal regions, each of which is associated
with a VM-DAS option (*.ini) file. The regions are defined
by a series of latitude/longitude coordinates for the
vertices that describe each polygon. The polygons are
of arbitrary complexity, and sub-regions within other
regions are allowed. The vertices are listed in order
proceeding around the perimeter of the region in either
direction. At intervals during operation, the AutoADCP
routine determines the ship’s position by reading
the last GGA entry in the most recent *.N1R file. This
position is then compared with the regions in the region-file,
in the order in which they are listed, stopping at the
first instance when the ship’s position falls within
one of the regions. By arranging the order in which
the regions are listed, with small sub-regions listed
first, it is possible to control the operation of the
ADCP in a complex geographic area.
Aside from controlling the operation of the ADCP through
the different option files, the AutoADCP routine periodically
checks that the data collection process is continuing
by checking the size of the *.ENR file of the highest
numbered data collection session. If the *.ENR file
has not changed in size since the last time it was queried,
it is assumed that the data collection has stopped prematurely.
It is possible that someone stopped the data collection
from the keyboard inadvertently, or there was some other
fault that caused the program to hang. Regardless of
whether or not VM-DAS is still running, the task manager
is used to stop VM-DAS after which VM-DAS is restarted
and data collection re-initiated. This ability to monitor
the continued operation of a program is referred to
as a software watchdog timer and it relies on the continuing
operation of the operating system, the network and the
AutoADCP program. Thus, the watchdog will not protect
against a system crash, although it should protect the
data collection process during most other conditions.
The steps in setting up the AutoADCP system include
the following:
- Create an AutoADCP subdirectory under C:\Program
Files and copy into it the AutoADCP executable, Visual
Basic source code, and example control and regions
files
- Make a shortcut on the desktop for the AutoADCP
executable. Change the icon to the one in the AutoADCP
subdirectory.
- Generate or edit an AutoADCP control file so that
it points to the correct files for the current application
and computer. Included in the control file are: paths
to AutoADCP.exe and VM-DAS.exe (not the shortcuts),
the path to the options (*.ini) files, the default
options filename, the path and name of the history
file, and the path and name of a favorite ASCII editor.
- Define a set of regions. These are usually based
upon water depth and areas where bottom track would
or would not be used. Include port areas where you’d
like the ADCP to be on so that it can continue to
acquire navigation data but where data collection
will be minimized. Each region should be associated
with its own options (*.ini) file.
- Set up a series of option files for each of the
regions. This can be done either using the option
editing feature of VM-DAS or by directly editing the
*.ini files using an ASCII editor.
- Carefully go through each options file to ensure
that it has the correct configuration for the associated
region and that all the paths and/or filenames are
correct for the PC controlling the ADCP. There are
a lot of details in these files so go through them
thoroughly.
- Check the *.txt file or files that will be pointed
to by the options files. Refer to the BroadBand or
Ocean Surveyor manuals for the meaning and optimal
settings for the commands.
Once the AutoADCP system has been set up, double click
on the desktop icon to start the program. When AutoADCP
is running, you will see that there are several options
in the menu across the top that will load the control
file and start and stop VM-DAS and the data collection.
See the example AutoADCP screen in Figure 1. Below the
menu are a series of text boxes that show which files
are controlling the data collection and where the ADCP
data is being stored. Below those boxes is displayed the
history of activity during the current and all the past
sessions contained in the history file. To the right of
the history box are several buttons that use the ASCII
editor that you have specified in the AutoADCP control
file to display the region, option (*.ini) and *.txt files.
Viewing and editing of these files can be done while data
are being collected, but configuration changes will only
take effect when and if the VM-DAS reloads those files.
There is also a button which allows you to add comments
to the history file which you might do, for instance,
if you have made temporary changes to test the performance
of various ADCP settings. The last set of boxes in the
lower right-hand corner show the UTC time and the ship’s
GPS position obtained from the *.N1R file the last time
that it was queried.
The actual operation of AutoADCP is controlled by the menu across the top
of the window. First load the AutoADCP control file.
This will bring up a dialog box to designate the proper
control file. After the control file is loaded, the
region file text box will show the region file specified
in the control file and the history text box will display
past history, and that AutoADCP has started. The next
menu item starts VM-DAS. The VM-DAS window should open
with a blank screen. The next menu item causes VM-DAS
to load the default option file specified in the control
file. If for some reason VM-DAS does not correctly open
the option file, close VM-DAS using the close VM-DAS
menu button, re-open VM-DAS and load the option file.
At this point, the option and *.txt files should be
displayed in the text boxes. Start Data Collection begins
the data collection process, and the output file preface
will be displayed in the data files text box. The GPS
time and ship’s position boxes will remain blank
until the navigation file is queried for the ship’s
position. When the ship crosses from one region to another,
AutoADCP will stop the data collection, load the appropriate
option file specified in the region file and restart
data collection using the new configuration. The change
in regions will be noted in the history file. If for
some reason the data collection stalls, the watchdog
timer will discover this after a reasonable interval
and attempt to restart the data collection. This also
will be noted in the history file. When data collection
is complete or if you want to use VM-DAS to edit a configuration,
stop the data collection first using the AutoADCP menu,
otherwise AutoADCP may notice that data collection has
stopped and will restart data collection. When data
collection is done, stop the data collection, close
VM-DAS, and quit AutoADCP using the menu buttons.
If you find any bugs in the program or have suggestions
for its improvement, please contact Charles Flagg, (631)
344-3128, flagg@bnl.gov
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