LADCP BB150 Commands, explained ------------------------------- 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!