UH LADCP Documentation

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LADCP BB150 Commands, explainedΒΆ

Read the manual for the WH150.cmd or WH300.cmd to find explanations for the commands. Many are similar. It’s a good homework project. If you make a file like this for the WH300 or WH150, let us know and we’ll replace this file with yours.

################################################################
# The following lines are the contents of the file
# beamcoords_16_8.cmd, which contains the commands to be sent to the
# ADCP at the start of a deployment:
################################################################
CR1
RA
RS
WV330
WN32
EZ0011101
EC1500
EX00100
WP1
WF1600
WS800
WT1600
WM1
WB1
WE0150
WC056
BP0
CP255
CL0
TP 00:00:00
TE 00:00:01.00
TB 00:00:02.60
TC 2
CF11101
################################################################
# END OF beamcoords_16_8.cmd
################################################################

Explanation of file contents:

The "16_8" refers to 16-metre pulses, 8-metre bins.

The entries in this file are a little arcane, but Jules assures me
that they do actually work, so trust them. The pinging regime this
file creates is such that a three-ping "burst" is transmitted:

PING---1 second pause---PING---1.6 second pause---PING

(the 1.6 seconds is the result of a "burst time" of 2.6 seconds, less
the 1 second between the first two pings).

The order in which the commands is given is important.

N.B., "WT" is an ADCP command, but it is also an abbreviation used in
RDI documentation for "water tracking".


################################################################
Quick explanations:

CR1               Retrieve factory settings
RA                Show number of deployments recorded
RS                Show recorder space used
WV330             Ambiguity velocity (cm/s, radial)
WN32              Number of depth cells
EZ0011101         Sensor source
EC1500            Speed of sound
EX00100           Coordinate transformation
WP1               Pings per ensemble
WF1600            Blank after transmit (cm)
WS800             Depth cell size (cm)
WT1600            WT transmit length (cm)
WM1               WT profiling mode
WB1               Bandwidth control (1=narrow)
WE0150            WT error velocity threshold (mm/s)
WC056             WT low correlation threshold (%)
BP0               BT pings per ensemble
CP255             Transmit power (0-255)
CL0               Battery saver mode (0==no sleep between pings)
TP 00:00:00       *minimum* time between pings (min:sec:hundredths_of_seconds)
TE 00:00:01.00    Time per ensemble (hh:mm:ss.hundredths_of_seconds)
TB 00:00:02.60    Time per burst (hh:mm:ss.hundredths_of_seconds)
TC 2              Ensembles per burst
CF11101           Flow control

################################################################
More in-depth explanations for the more complicated commands;
commands sorted alphabetically:


BP--Bottom-track pings per ensemble. A value of zero (BP0) means the
ADCP does not collect bottom-track data.

CF--Flow control. Argument is firmware switches. The digits in
"CF11101" mean (in order):

   (1) "1": Automatic Ensemble Cycling--automatically starts the next
   data collection cycle after the current cycle is completed.

   (2) "1": Automatic Ping Cycling--Pings immediately when ready,
       rather than waiting for user input.

   (3) "1": Binary Data Output--Sends the ensemble in binary format
       (if serial output enabled).

   (4) "0": Serial output disabled ("no ensemble data are sent out the
       RS-232 interface").

   (5) "1": Enable Data Recorder (i.e., internal recording).


CL--Battery saver mode. "0" means no sleep between pings; i.e., ping
as quickly as possible.

EX--Coordinate transformation. The switches in "EX00100" cause the
following behaviour:

   No transformation. Radial beam coordinates (i.e.,
   1,2,3,4). Heading, pitch, roll not applied.

   Collect tilts (pitch and roll) data.

   3-beam solutions not allowed.

   Bin-mapping not allowed


EZ--Sensor source. Selects the source of environmental sensor
data. Syntax is EZcdhprst. Switch meanings in "EZ0011101" are:

   c: Speed of sound. "0" means use manual value, rather than
   calculating from manually-entered press, sal and temp.

   d: Depth sensor. "0" means use manual value.

   h: Heading. "1" means use internal compass.

   p: Pitch. "1" means use internal tilt sensor.

   r: Roll. "1" means use internal tilt sensor.

   s: Salinity. "0" means use manual value.

   t: Temperature. "1" means use internal temperature sensor.


TB--Time per burst. "TB 00:00:02.60" means that bursts start every 2.6
seconds. The ADCP will sleep if it has any free time between bursts.

TC--Ensembles per burst. "TC 2" means 2 pings are sent before sending
the ensemble to the recorder (or through the I/O cable).

TE--Time per ensemble. Sets the *minimum* interval between
data-collection cycles. TP is the time between pings, and WP is the
number of pings per ensemble. The time per ensemble, then, should be
*at least* TP multiplied by WP. If TE is greater than TP*WP, that is
okay: there is just a pause between ensembles. WF, If TE is less than
TP*WP, though, the ADCP automatically increases TE (if TE=0, the ADCP
starts collecting the next ensemble as soon as it finishes processing
the previous ensemble).

TP--The *minimum* time between pings. During time interval TE, the
ADCP transmits WP pings. If TP=0, the ADCP pings as quickly as it
can. If TP is greater than the ensemble time divided by the number of
pings, then TE is automatically increased. "Several commands determine
the actual ping time (WF, WN, WS and actual water depth)".

WB--Bandwidth control. "Sets profileing mode 1 bandwidth (sampling
rate)"...?

WC--Water-tracking low correlation threshold (percent). Data is
flagged as bad if the correlation of water-tracking is below this
threshold.

WE--Water-tracking error velocity threshold (mm/s). If error velocity
greater than this, data flagged as bad.

WM--Water-tracking profiling mode. Chooses type of ping
transmitted. Modes are different for shallow water, extended range,
etc. The "WM1" used in beamcoords_16_8.cmd denotes "dynamic sea
state".

WP--Pings per ensemble. If WP*TP > TE (the ensemble interval), then TE
is automatically increased.


WT--Water-tracking transmit length (cm). This is the length of a
single ping in space. If WT=0, then the ping length is set to the
depth cell size.

WV--Ambiguity velocity (cm/s, radial). Low value is better
performance, but too low causes ambiguity errors. Rule of thumb: set
value to sum of vessel velocity and horizontal water velocity.

################################################################
Work through the ping/ensemble regime for these settings.

Have:

   WP1             1 ping/ensemble
   BP0             Zero bottom-track pings/ensemble (i.e., no bottom tracking)
   TP 00:00:00     Ping as quickly as possible
   TE 00:00:01.00  At least 1 second between ensembles
   TB 00:00:02.60  Bursts happen every 2.60 seconds.
   TC 2            2 ensembles per burst

Adapted from TB command documentation example:

   There will be 1-ping "ensembles" every second (TE command). There
   are only two of these single-ping ensembles per burst, after which
   the ADCP sleeps until the 2.6-second burst period is
   finished; because the ensembles are 1 second apart, this takes 1.6
   seconds.

==> PING---1 second gap---PING---1.6 second gap...
    PING---1 second gap---PING---1.6 second gap...
    PING---1 second gap---PING---1.6 second gap...

Correct!