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HydroScat-6 User's Manual - Remote Sensing and Satellite

1. and both vary with temperature The following table shows typical values for a new battery Temperature T standby 4200 mAhr 1 8 mA 10 4800 mAhr 2 1 mA 20 5400 mAhr 2 4 mA 30 5700 mAhr 3 1 mA For example in continuous use at 10 C we would predict endurance of about 4800 mAhr 272 mA 17 6 hours For a burst mode application with active time of 20 seconds per hour at 30 C Lequiy Would be 3 1 mA 270 mA 20 3600 4 8 mA Total duration would be 5700 mAhr 4 8 mA 1190 hrs or about 49 days 7 2 Low Voltage Cutoff When the battery voltage falls to 9 9V indicating it is nearly exhausted the firmware will automatically put the HydroScat into an indefinite low power sleep state In this state the contents of the RAM will be preserved but no further data will be collected With its load thus reduced the battery voltage will typically recover and the battery will usually be able to preserve the memory for several weeks or longer HydroScats equipped with flash memory will retain their data even if the batteries fail completely In addition to the low voltage sleep which is controlled by software the battery control circuit will disconnect it completely if the voltage falls below about 8 volts This is unlikely under most circumstances but may happen after very long periods with no charging If this happens the battery will remain disconnected until the chargi
2. to clear the memory or any other key to abort 8 3 6 CLEARLOG Identical to CLEARRAM 8 3 7 D Transmits D packet of hexadecimal data See section 9 2 for a description of the format 8 3 8 DATE mm dd yyyy hh mm ss Sets the real time clock to the given date and time if provided If no date is given simply reports the current setting The year may be entered either as two or four digits If only two digits are entered years from 00 to 43 will be assumed 36 to be in the 21 century The real time clock is reset whenever power is turned off to the sensor Setting it accurately is not necessary to the operation of the sensor but may be useful for keeping track of logged data In the Crosscut terminal program the host computer s date and time for this command can be entered by pressing Alt D Reply 7405 01 97 14 51 02 8 3 9 DIR Displays a directory of the casts currently stored in memory Reply Cast Start Time Duration Samples 1 mm dd yyyy hh mm ss 2 3 hrs 12 345 2 mm dd yyyy hh mm ss 23 1 mins 3 456 Note that the duration is calculated from the time tags associated with the first and last packets in the cast If the user changed the setting of the HydroScat clock while a cast was in progress the duration displayed may not make sense 8 3 10 DOWNLOAD cast Causes the HydroScat to transmit data stored in its log RAM Cast is the number of a cast to transmit Use DIR to view the availab
3. 5 3 1 Loading Calibrations Calibrations can be loaded either directly from a connected HydroScat or from a file on the host computer To load an instrument s calibration check the Load Calibration From Instrument option while connecting to the instrument 13 section 5 4 To load a calibration from a file choose Select Calibration File from the File menu If you select a new calibration file while an instrument is connected or while a raw data file is open HydroSoft will only load it if it is of a matching type HydroSoft will inform you if the type does not match It will also warn you if the serial number of the instrument does not match that contained in the calibration file but it will offer you the option of loading it even if the serial numbers do not match Once a calibration file is loaded it remains in effect until a different one 1s loaded When you exit HydroSoft it stores the name of the current calibration file If the Automatically recall last selected calibration file option is selected in the Preferences dialog box the file will be reloaded the next time HydroSoft starts up If you have more than one data window open in HydroSoft you can select a different calibration file for each one The most recently selected file in any window will be saved as the default 5 3 2 Viewing And Editing Calibration Data You can see the details of the current calibration by selecting View Calibration from the File Menu Normal
4. r H HR 8 3 2 COLLECTING DATA Vaiss ee eoe Ee 8 33 DOWNLOADING DATA FROM THE HYDROSCAT 0 20 0 02 0 0000000 9 3 4 IDISCONNEGTING e 9 3 5 SWITCH ACTIVATED LOGGING 4 oreet veau eux d Ce EHE ERE 9 4 HYDROSOFT SOFTWARE eo gs eo ho bn eo Pa SV a no e Ve eros 11 4 1 INSTALLINGTIYDROSOET tert erue esee eiue toes 11 4 2 REMOVING HYDROSOFT 11 5 COLLECTING AND HANDLING DATA 13 5 1 PRIMARY DATA ead ck eee eee 13 5 2 HOUSEKEEPING DATA oi ferrent od eere este ct lere os ide Cede Ded 13 5 3 CAEIBRATION D ATA cel cates ti tei fere Peste ete ca ev 13 5 4 CONNECTING t ctii stunk 14 2 9 EOGGING SETUP eere edel eere fete ca eire cte dese Ce redes 16 5 6 SETTING THE HYDROSCAT S REAL TIME CLOCK esses eee eene 18 5 7 LOGGING VERSUS REAL TIME DATA e
5. CalTime 940441065 10 20 99 17 37 45 CalTemp 25 1 DepthCal 0 011509 DepthOff 27 776199 Channell Name bb470 1 1 0 105786 Gain2 1 000000 Gain3 9 814222 Gain4 97 364861 Gain5 994 677307 Mu 11 57230 Sigmal 0 998000 Sigma2 0 128000 Sigma3 0 012800 SOutOff 0 000000 SInOff 0 000000 ROutOff 0 000000 RNominal 10000 000000 Beta2Bb 26 790000 Bb2c 64 000000 TempCoeff 0 000000 Channel2 etc in same format End 57 58 10 1 10 2 10 3 10 TROUBLESHOOTING HydroScat 6 is unresponsive HydroSoft is unable to detect it Connect the battery charger or another external power source Check that the HydroScat is properly connected to the computer Select the Reset command from HydroSoft s Instrument or HydroScat menu making sure that it is addressing the port to which the HydroScat is connected Wait for 10 seconds after the reset completes then attempt to reconnect HydroScat 6 still does not respond after the above steps Note that this procedure will erase any data in the HydroScat 6 RAM but will not affect data in flash memory if your instrument is so equipped If it is possible the battery is discharged connect the charger for at least 5 minutes but DO NOT repeatedly connect the charger if the battery fails to hold charge this can cause damage Disconnect the charger from AC power Disconnect the charging cable from the HydroScat s underwater connector Plug the battery disconnect
6. Snorm4 15DE Snormb 1323 Snorm 2034 Snorm7 FB24 Snorms F952 Gain Status1 5 Gain Status2 5 Gain Status3 5 Gain Status4 5 Gain Status5 5 Gain Status6 5 Gain Status7 0 Gain Status8 nibble H 1 0 50 rror hecksum erminator 9 4 H Packet Format 9 4 1 Example Packet H346A023C060F4B510647FE04A6545CO66EFF04F34007050EFE06C837AF06B5FE05857 89705C6FF04F35A8807C9FF000000000000000000000000000077210B069120 CR LF Param Type ASCi ASCHBytes Exampie 11 Time signed HHHHHHHH 8 S46A025C Soom 4 F Ren signed 4 4851 signed 4 967 Baci signed 2 FE Sigot2 signed 4 0446 signed 4 s ReOf2 signed HHA 4 oe Back signed 2 FF Soons signed HHHH 4 94 Res signed 4 407 ReOfS signed HHHH 4 050 Backs eed 2 FE Sofa sioned 4 9608 Rea signed 4 m BR DO BY BY BP PO S S eR ReOf4 signed 4 0685 5 Backt signed 2 FE Soots signed HHHH 4 9585 Res signed 4 7897 ReOf5 signed 4 0566 Backs signed 2 F Sigof6 signed 4 F3 signed 4 558 ReOf signed 4 9709 signed 2 FF Sigo signed 4 20000 Ref signed 4 0000
7. room temperature is over 20 hours of continuous operation When discharged at 0 C the same charge provides at least 14 hours of operation Internal leakage causes the battery to slowly discharge even with no load The self discharge rate is highly temperature dependent After one month at 0 C the battery may lose 10 of its charge The loss at least doubles at 20 C and continues to increase at higher temperatures Capacity also decreases slowly as the battery ages The capacity loss depends greatly on charging conditions but 15 typically less than 10 after 200 charge discharge cycles and 20 after 500 cycles Approximate discharge time for the battery can be calculated as follows Please note that it is not possible to accurately account for all the factors that affect battery capacity so you should use these calculations with caution and temper them with your own experience First calculate the equivalent total current drain for your sampling schedule t ER I active Ia standby sample total where fyctive tioiai 1s the fraction of the deployment time during which the sensor will be active In burst mode this will be the sum of the burst warmup time and burst length divided by the burst interval For continuous collection its value is 1 29 typically averages 270 mA over the course of the battery s discharge Given Ton l otal equiv where is the battery capacity with units of current time
8. 8 DIRECT COMMUNICATION AND COMMANDS HydroScats are configured and controlled with commands sent via their serial communication port When you use HydroSoft the commands needed for routine operation are generated automatically and you do not need to know the details However you can type commands manually and view the HydroScat s replies directly via HydroSoft s terminal window or a generic terminal program Some less common commands are accessible only through this method 8 1 Communication Protocol HydroScats communicate through a standard RS 232 serial connection with 8 data bits no parity one stop bit and no handshaking The default baud rate is 9600 but it can be set to other standard rates up to 57600 see section 8 4 1 8 2 Command Conventions The HydroScat waits until it receives a carriage return line feed or other control character before responding to a command It responds to every command but does not echo characters when it receives them If it receives command it does not understand it will echo the command followed by a question mark HydroScat s responses usually start with an apostrophe 9 Error messages start with an exclamation point and primary data messages start with an asterisk Commands are insensitive to case They are shown below in upper case for clarity Some commands accept arguments which are separated from the base command and from each other by commas Arguments may be
9. By using the magnetic switch one can collect an extended series of casts without connecting to a computer The starting and ending times of each cast are recorded in the log memory so that casts can be later downloaded individually or as a group The sensor may be wakened from sleep by command from the serial port regardless of whether the switch is or off However the software SLEEP command will not work if the switch is Some early HydroScat 6 s that were retrofitted with batteries do not have a magnetic actuator attached to the end cap instead a separate magnet is used to actuate the switch which is located directly between the two electrical connectors Momentarily placing the magnet between the connectors toggles the instrument between the logging and sleeping states On instruments with separate magnets do not leave the magnet in place more than 1 second Leaving it too long after waking the sensor could cause it to go back to sleep when the magnet is withdrawn 5 9 1 Important Note On Using External Power Sources Because the switch was designed specifically for use with the internal battery it may not function as expected when the HydroScat is powered by an external source If the external voltage exceeds the voltage of the internal battery the HydroScat 6 cannot detect that the switch is Similarly if the voltage of the internal battery falls below the external source during a cast and the switch is on
10. HydroSoft to set the clock and reconfirm the setting When it is finished click the Close button to close the dialog box 5 7 Logging Versus Real Time Data Whenever collecting data in response to a Start command from HydroSoft or from its magnetic switch HydroScats simultaneously transmit them from their serial port Data can also be collected on demand without internal logging by sending D or H commands each time data are required see section 8 for information about the commands and section 9 for the data formats 5 8 Log Memory Capacity The base memory for a HydroScat includes 256K of RAM of which most is reserved for data logging This provides a capacity of about 7 000 HydroScat 6 samples we use the terms sample and packet interchangeably to indicate a set of simultaneous measurements from all the channels The optional flash memory can be installed in various sizes up to 512 MB where each megabyte can hold about 30 000 samples The flash memory also prevents loss of data in case of battery failure 5 9 Using The Magnetic Switch The magnetic switch located on the back end cap of the HydroScat see Figure 3 on page 4 signals the sensor when to start and stop data logging When switched on the HydroScat will wake and begin collecting data as if the START 18 command were sent to it When switched off it will stop sampling and go to sleep as if the STOP and SLEEP commands were sent
11. TIME hh mm ss Sets the real time clock to the given time does not affect the date If no time is given in the command simply reports the current setting The real time clock is reset whenever power is turned off to the sensor Setting it accurately is not necessary to the operation of the sensor but may be useful for keeping track of logged data Reply 05 01 97 14 51 02 8 3 25 TIMERES mode Causes the HydroScat to report time in high resolution 0 01 s or low resolution 1 s mode Specifying a mode of H high or 1 on will enable the high resolution mode Specifying a mode of L low or 0 off will disable the high resolution mode In high resolution mode the data packet format is slightly different and is denoted by instead of D at the beginning of the line See section 9 1 for details of the data formats Reply to TIMERES H or TIMERES 1 Time Resolution high 0 01 second Reply to TIMERES L or TIMERES 0 Time Resolution low 1 second 8 4 Special Purpose Commands The following commands are not needed for routine operations and should be used with great care 8 4 1 BAUD rate Immediately sets the baud rate at which the instrument communicates If sent without an argument reports the current baud rate setting Valid rates are 4800 9600 19200 38400 and 57600 The actual baud rate set by the instrument is usually slightly different from these rates although you
12. at the time it will be interpreted as if the switch were turned off prematurely ending the cast You can avoid this situation in two ways One is to start and stop casts with commands sent by a computer rather than the magnetic switch The second is to operate the switch while the external power source is off or disconnected and start casts by turning the switch on only momentarily for less than one second When it is wakened by the switch but the switch is then rapidly turned off the HydroScat ignores the off transition and continues logging indefinitely as if the switch were still on this allows it to accommodate a detached magnet as an actuator When using this technique you can verify that a cast has been started by checking that the lights have turned on although they may not turn on immediately if you have programmed a start up delay Even if the switch operates normally with your external power source connected you should use the momentary on action of the switch to start long term casts to avoid possible premature termination 19 5 10 Downloading Logged Data HydroSoft s Get Data From Instrument command enables you to view a list of casts stored in an instrument s memory transfer casts from the instrument to files on your computer and erase the instrument s memory Casts you transfer are stored in individual files whose location and base name you specify The cast number is appended to the name of each file
13. double click on the graph or select Properties from the Graph menu 16 Click 89 or select Stop from the HydroScat menu 17 Close the open data file by selecting Close from the File menu or clicking on the button If desired save the file when prompted Downloading Data From the HydroScat 18 Select Get Data From Instrument from the HydroScat menu 19 After several seconds a directory of casts in memory will appear The last cast listed should be the one you just recorded If that cast is not already highlighted click on it to highlight it or click the Select All button 20 Click the Browse button to select a directory in which to save downloaded data files In the resulting dialog box select a directory and click the Select button 21 If it is not already checked check the Create calibrated data dat files option 22 Click the Download button to begin transferring data casts Disconnecting 23 After you are finished communicating with the HydroScat select Disconnect from the HydroScat menu When asked Put HydroScat to sleep before disconnecting click Yes 24 Unplug the cable from the HydroScat s underwater connector Switch Activated Logging 25 To start a cast when the HydroScat is asleep and disconnected from the computer move the magnetic switch to the on position see Figure 3 on page 4 26 To end a cast return the magnetic switch to the off position 4 HYDROSOFT SOFTWARE Hydr
14. individually omitted in which case they will have no effect For example if a command accepts three arguments in form cowvaNp argi arg2 arg3 you may adjust only arg3 by entering 8 3 Routine Commands 8 3 1 BATT BATT displays a brief subset of the data displayed by CHARGE including the battery voltage and current and the charging rate if any If a charge is in progress the duration of the charge and the cumulative charge and energy are 33 shown If not the cumulative charge and energy consumed since the last charge if any are shown 8 3 2 BURST on warmup duration cycle totalDuration logPeriod start Delay autoStart sleepOnMemFull Similar to LOG but lists the burst parameters first to make them easier to enter In burst mode i e if is nonzero upon receipt of the START command or activation of the magnetic switch the HydroScat waits for the number of seconds specified by the LOG command s startDelay parameter It then collects data until duration seconds have passed At the end of the burst it goes into low power sleep mode until cycle minutes have passed since the beginning of the previous burst At the beginning of each subsequent burst it waits for warmup seconds before resuming collection When totalDuration hours have passed since the beginning of the first burst the HydroScat will go into an indefinite low power sleep If duration is zero burst mode will be disabled reg
15. is scaled to fit into an unsigned byte as when it is transmitted in the normal D data packet To convert it to degrees C divide by 5 and subtract 10 For example 176 corresponds to 25 2 C VA is the voltage supplied via the HydroScat 6 s main 4 pin connector VB is the voltage of the internal battery VBk is used to detect when the charging supply is connected these voltages are expressed in hundredths of volts For example VA above is 13 5V Aux is used to measure the battery charge or discharge current in sensors with batteries The value shown is 840 times the current in amps In sensors without batteries Aux is not used Gain status indicates whether the current gain settings are appropriate to the measurement conditions A value of zero indicates the gain is suitable Positive one means it should be increased and negative one means it should be reduced In this example channels 1 3 and 5 are judged to have too much gain and will be reduced by the autogain algorithm if it is enabled The next sample displayed would show those channels set to gain 4 The averaged signal levels in this example are well below saturation but as indicated by the error value of 2 some channels must have received excessive signals at some point during the sampled interval 46 9 DATA PROCESSING REFERENCE 9 1 Raw Data Formats HydroScats can produce several data packet formats as well as reply to many commands see section 8 The D da
16. name Beta2Bb 140 Volume scattering of pure water at 140 degrees bow Backscattering coefficient of pure water 53 Normally the value of 140 used in this equation would include the sigma correction explained in the following section The pure water scattering values and are calculated by HydroSoft according to parameters set in the dialog shown below This is displayed in response to the Backscattering Parameters command on the File menu default values are from A Morel Optical Properties of Pure Water and Pure Sea Water Optical Aspects of Oceanography M G Jerlov and E S Nielsen eds Academic Press New York 1974 chap 1 pp 1 24 However by selecting the custom option you can modify the model For special applications you can also remove the pure water factor entirely by setting the custom parameters to zero Backscattering Parameters Backscattering coefficient calculation Pure water scattering calculation b 227 B B by B CD aZ C Morel Salt Water C Morel Fresh Water C Custom C Use values from calibration file o B Aa 346 05 _ Use this value 108 b Ay Ag 2 Es About Cancel 9 6 Sigma Correction Sigma correction is an adjustment to improve the accuracy of backscattering measurements in highly attenuating water Some light that would otherwise be detected as backscattering is lost to attenuation in the water betw
17. of the transmitted light scattered in the desired range of angles is extremely small and one of the prime considerations in the optical design is maximizing this inherently low throughput Thus we maintain at least a 2 cm open aperture throughout the optical path PRIMARY SENSING VOLUME ue Edi mi gh E P gt ee i z p ES x i pos gt gt V 3E N cz P ao DISTANCE Figure 1 Side View of Backscattering Measurement Geometry 1 3 Electronics The inherently low optical throughput of the backscattering measurement demands very sensitive electronics In clear water the backscattering signals arriving on the detector may be as low as a few picowatts At the same time natural background light may be orders of magnitude larger To separate backscattering signals from background light the LEDs are modulated at audio frequencies and synchronous receiver electronics used to discriminate against interfering signals Each channel has a different frequency to prevent any crosstalk between channels This also allows us to discriminate between backscattering and fluorescence see section 1 4 To allow measurement in a wide range of waters and to accommodate the requirements of our calibration procedure the gain of each channel can be set to one of five settings spaced a decade apart Only three of these settings are used in normal measurement situ
18. time share flonly Sample Period bs seconds Start Delay my Seconds 676nm bb fluorescence sharing nee fils C bbony time share C flonly Burst Mode Burst mode on Burst length 105 seconds Burst interval minutes Burst Warmup fic seconds Total Duration hours Reload Close When the Sampling Options dialog is first open it may take several seconds for the current settings to be retrieved from the HydroScat Similarly when you click the Apply button there will be a noticeable delay while HydroSoft transmits then confirms the new settings This confirmation is important because it allows you to check that the settings were entered as you intended The HydroScat may reject settings it cannot support for example burst lengths that are longer than the burst interval Make these settings nonvolatile Sample Rate and Sample Period by definition have an inverse relationship Changes you make to one will automatically affect the other Note however that the period which has a resolution of 0 01 second is the controlling parameter Therefore some exact sample rates are not available For example if you enter a rate of 3 per second the calculated period will be rounded to 0 33 s and the rate will be set to 3 03 per second When logging is started either by software command or by turning on the external switch the HydroScat will wait for the number of seconds s
19. 4 nibble 1 Gain Status5 nibble 1 Gain Status6 nibble H 2 2 2 2 55 55 5 5 5 55 RY AR aj O1 O1 C1 O1 47 Gain Status7 nibble Gain Status8 NNNM DepthRaw Error bye HH 2 Checksum 42 Temno 2 TOTAL 62 9 2 3 Packet Flag Each data packet with an asterisk character Other transmissions for example replies to commands may begin with other characters 9 2 4 Packet ID The packet described here is identified by a D in this position HydroScats may produce other packets of various lengths with other identifiers 9 2 5 Time TIME is in seconds If the HydroScat s real time clock has been set accurately See the description of the TM and DT commands in the User s Manual a time of zero represents Midnight January 1 1970 The time shown in the example above 346A023C corresponds to November 12 1997 at 19 23 40 When power is first applied to the HydroScat the time may proceed from a random value It is not necessary to set the time if absolute time data are not required 9 2 6 Snorm There is one 16 bit Snorm value for each of the 8 optical data channels Note that some channels may be disabled as indicated by their Gain Status values in which case the Snorm value is meaningless It is calculated by the HydroScat from S R Sig SigOff SigDark norm no
20. 5 10 1 Basic Procedure Connect the HydroScat to your computer s com port using the supplied power data interface cable start HydroSoft and use HydroSoft s Connect command to establish communication Select Get Data From Instrument on the HydroScat menu e A dialog box like the following will appear m HydroScat Logged Data Loaded Memory Status 9783351 001471 bytes 8796 free Load Directory ERS EET BET Qm A Delete All Select All Use ShiR click to select groups of casts Ctrl click to select or deselect individual casts Base d HSoft Test Files Browse Create calibrated data dat files raw files are always stored Close e After the directory is loaded select the cast or casts you wish to retrieve e Enter a base file name for the downloaded files The cast number will be appended to this base name to create a unique name for each cast you download If necessary click Browse and select a destination directory for the downloaded files 20 Click Download Depending on the quantity of data and baud rate downloading may take some time Status messages and a graphical indicator will show the download progress To clear the instrument s memory after verifying the desired casts were downloaded click Delete All Click Close to dismiss the dialog box 5 10 2 Details Depending on the number of casts stored loading the dir
21. 77 Cal Time 13660 38 Model and serial number are self explanatory config string describes the sensor s hardware configuration Among other things it indicates the wavelength set quantity of RAM communication protocol and whether it has an internal battery ID is simply an identifying name which we usually fill with the name of the purchasing institution Address is used when several instruments share communication lines The default setting for all HydroScats is which indicates no address is required If an address other than is specified the HydroScat will respond only to commands that begin with that address Not all HydroScats have the same warranted depth rating so maximum depth is recorded here along with the sensor s other attributes The firmware version number displayed is programmed into the firmware s source code and therefore cannot be changed except by installing different firmware The calibration time shown is in the real time clock s raw reading in seconds since midnight Jan 1 1970 at the time the calibration or configuration parameters were last changed This cannot be directly entered but is updated automatically 8 3 14 LOG period delay sleepOnMemFull autostart burstMode burstWarmup burstDura tion burstCycle totalDuration Period is the time in seconds between samples that are logged and transmitted on the serial port Delay is the number of seconds the instrument will wait a
22. HydroScat 6 Spectral Backscattering Sensor amp Fluorometer User s Manual Revision 1 Hydro Optics Biology amp Instrumentation Laboratories 4 Lighting the Way in Aquatic Science www hobilabs com support hobilabs com Current Firmware Version 1 95 Other firmware versions may differ in some respects Contact HOBI Labs for information on how to upgrade HydroScat firmware Revisions I February 19 2010 Include description of fluorescence time sharing in section 5 5 Add deployment cage section 11 expand troubleshooting 10 H June 15 2008 Add note to avoid alcohol for cleaning acrylic windows 2 3 G May 14 2008 Add note about factory maintenance 2 7 F June 6 2007 Correct and clarify sigma correction sections 9 5 and 9 6 E October 22 2004 Update description of Sigma correction to reflect changes in HydroSoft 2 7 section 9 6 D November 17 2003 Correct format of time field in packet shown in section 9 3 2 Change data download DD cable to power data interface PDI cable Add description of exponential sigma correction section 9 6 Remove description of PDI box was section 10 January 22 2002 Add single connector configuration and reorganize section 6 Add note about magnetic switch interaction with external power supply section 5 9 1 Correct noise levels cited in section 5 5 1 Add STARTNOLOG command 8 3 19 Expand explanation of low volt
23. ReOf7 signed 4 0000 Back signed h 2 00 Soone signed 4 20006 Res signed 4 0000 AA PM A A BR BR BR DO BRP AJA 51 erminator 9 4 2 Time Same as D packet time 9 4 3 SigOff Ref RefOff These three values one set for each of the optical channels are incorporated into the calculation of Snorm and are not needed for normal post processing 9 4 4 Back This signed integer indicates the amount of background radiance incident on the detectors Its value is normally zero or negative from the HydroScat 6 A large value indicates bright background light presumably sunlight which may contribute to noise in the backscattering data 9 4 5 VsupA VsupB Vback These show the voltages of up to three power supplies for the instrument The HydroScat only draws power from the source with the highest voltage and only one need be supplied for normal operation Different sensor configurations may assign the voltages differently The value reported is 10 time that actual applied voltage For example VsupA above is 77 Hexadecimal 119 Decimal representing 11 9 Volts 9 4 6 Aux Not presently used 9 4 7 Checksum Same as D packet 9 4 8 Terminator Same as D packet 52 9 5 Calculating and Each optical channel of each HydroScat has a unique set of calibration coefficients needed to convert its data to engineering units These coeffici
24. The configuration version number identifies the format in which the current information was stored Finally the cal time shows the date and time at which the configuration and calibration data were last altered This is updated automatically and cannot be edited The same parameter is displayed in raw form by the ID command 8 4 7 X X 15 used extensively during testing and troubleshooting since it displays a comprehensive report of the HydroScat 6 s most recent raw data as follows Raw data are also discussed in section 9 1 time 2856 error 2 samples 733 on 11 off bb440 4611 4546 8840 2393 4 47 120670 13110 1707 12730 1557 1 8128 bb470 10724 1722 16239 2031 3 5068 bb510 6761 1616 13869 1604 2 3233 bb590 14818 1910 17587 1865 7 6528 120620 11472 2003 12729 1650 13 6396 1510 0 0 0 0 0 0 1670 0 0 0 0 0 0 gains 555555 5 5 depth 1661 temp 176 VA 135 VB 79 VBk 53 Aux 5888 gain status 1 0 1 0 1 000 Time is the current raw setting of the real time clock in seconds since midnight 1 1 1970 Error is a one byte variable in which each bit is a flag for a particular error condition described in section 9 2 10 In the display above error has the value 2 indicating that one or more of the signal channels saturated at some point during the sampling time The second line shows how many samples were averaged to produce the displayed data In this case the signals were averaged over 733 samples abou
25. age cutoff section 7 2 November 6 2001 Update HOBI Addresses February 16 2001 Start of revision tracking Extensive reorganization changes to incorporate HydroSoft separate HydroScat 2 from HydroScat 6 ii TABLE OF CONTENTS 1 eye oua 1 1 1 OVERVIEW ates esr edt 1 1 2 2 22 PE dat dete e 1 1 3 BEECTRONIGS 5 Sodas e e ete d E re 2 1 4 FLUORESCENCE MEASUREMENTS 0 12 00000 0 0 100200000000 3 2 PRECAUTIONS AND 1 11 5 2 1 cT 5 23 GENERAL GCEBANING be saat re desastre iR cia teret 5 2 3 MANDO WS cies esit vectis 5 24 PRESSURE TRANSDUCER 4 5255 drerit a t i qe ru ere wed 5 2 5 CONNECTORS tiefe EI E E EE edite seid vedo ice vtm orent eds ute 6 2 6 MOUNTING AND DEPLOYMENT 1 5 oe e e ede E ebrei pieta tee deae wee 6 2 3 CALIBRATION AND MAINTENANCE ccccccccsccsssessececececsesenssaececeececsessaaeceeeceesessaaececeeecsensaeeeeeeeseneea 7 Se QUICK STARE e 8 3 1 DE EU isis
26. ap 2 PRECAUTIONS AND MAINTENANCE 2 1 Precautions Protect the windows Cover the instrument face whenever possible Do not use acetone to clean any part of the instrument Thoroughly clean the HydroScat with fresh water before storing it Avoid letting the sensor sit in direct sun on deck If the water temperature is very different from the temperature on deck let the instrument stabilize in the water for 10 minutes before collecting data e See section 7 for information about maintaining internal batteries 2 2 General Cleaning Upon removing the instrument from the water rinse it thoroughly with fresh water and rinse the windows with distilled or deionized water Periodically inspect the windows for contamination 2 3 Windows HydroScats have acrylic windows that are easily scratched Minor scratches will not seriously compromise the measurements but the windows must be treated carefully to avoid abrasion Do not use acetone concentrated alcohol or abrasive cleaners Do not over clean the windows Unless the windows become visibly dirty during use it is usually sufficient to rinse them with clean fresh water each time the instrument is removed from the water If necessary clean them with a mild liquid soap or lens cleaning solution 2 4 Pressure Transducer If your HydroScat 6 is equipped with an oil filled pressure reservoir and capillary tube the reservoir may require occasional refilling This is part of
27. ardless of the value of on If cycle is zero the HydroScat will sleep indefinitely after only one burst If totalDuration is zero the total duration will not be limited Burst mode 1 ON Warmup time 5 seconds Burst duration 15 seconds Burst cycle 10 minutes Total duration 0 hours not in effect Sampling and Logging Parameters Log Period 1 seconds Start delay 60 seconds Sleep when memory full 1 Start on power up 0 8 3 3 CHANNELS Lists the wavelengths and functions of the 8 data channels of a HydroScat 6 in the order in which the HydroScat produces them Reply 71 bb442 2 bb671 3 bb470 4 bb510 5 bb589 6 bb671 7 1510 excitation bb470 34 8 1671 excitation bb442 8 3 4 CHARGE CHARGE takes no arguments and displays a summary of the battery s charge and discharge status This includes information about the most recent or current charge and discharge as well as cumulative information about past charges Example reply Voltage 11 09 v The voltage of the battery at the time of the status report This could range from 16V during fast charge to 10V near the end of the discharge the sensor goes to sleep automatically when the voltage falls below 10 Current 0 30 A discharge The current flowing into or out of the battery at the time of the status report A negative current means the battery is being discharged The maximum normal discha
28. ation However in shallow water over a reflective bottom under bright solar illumination light reflected into the windows may cause high noise levels or in extreme cases saturation In such situations it may be advantageous to mount the sensor horizontally so that the backscattering receivers do not face the bottom Some experimentation may be required in such cases HydroScats equipped with internal batteries can be deployed with only a mechanical cable or attached to an existing package without additional cabling If the HydroScat is attached to an existing package make sure that the field of view of the sensor is unobstructed as mentioned above KEEP 30 CONE CLEAR 13 60 34 5 cm Figure 4 HydroScat 6 Side View 2 7 Calibration and Maintenance For exacting scientific applications we recommend calibrating the HydroScat 6 every six months or 200 hours of operation At a minimum we strongly recommend annual check ups at HOBI Labs With the proper equipment available from HOBI Labs users can perform their own calibrations For more information about the equipment and procedures involved see the HOBI Labs Backscattering Calibration Manual available at www hobilabs com Even if you perform your own calibrations it is very important to return the HydroScat 6 to HOBI Labs preferably annually for a complete functional test and check out Inspection and testing by trained factory personnel can uncover items that ar
29. ations the lowest two are used primarily for calibration The HydroScat normally selects the appropriate gain automatically based on the amount of backscattering detected as well as the amount of background light In order to compensate for residual electronic offsets the HydroScat periodically turns off each LED briefly to measure the receiver output in the absence of signal The LEDs are turned off for 0 1 second approximately every 2 seconds and the resulting offsets are continuously averaged and subtracted from the signals Note that this is not the modulation referred to previously that separates the backscatter signals from each other and from background radiance those modulations are too rapid to be visible 2 2469 DETECT Cy N 2 J 1 2 ES N iB i N SOURCE source UEM gt DETECT DETECT J 3 Figure 2 HydroScat 6 Front Optics End Cap 1 4 Fluorescence Measurements The HydroScat uses an innovative method invented by HOBI Labs to measure fluorescence with the same optics used for its backscattering measurements Because each LED in the HydroScat is modulated at its own frequency fluorescence excited by a particular channel can be identified by the excitation channel s characteristic frequency even though its emission falls into the optical bandwidth of another channel The HydroScat receiver channels can b
30. attering probability which can be set by the user The numerator of this expression is the uncorrected b excluding that of pure water The Sigma Correction Parameters dialog box is shown below with typical settings for a HydroScat sensor The default settings are appropriate for most cases The main exception is it may be appropriate to adjust the value of C if Chlorophyll levels are high and can be estimated HydroScats that are appropriately configured may provide this information but the user must provide a calibration to translate the HydroScat s readings into Chlorophyll concentrations 3 Sigma Correction Parameters Sigma function for backscattering correction ki exp amp y Ey Estimation of Kbb Ky a 04b 0 064 4 c9 1 0 2 4 440 0 014 ag 400 ya A 400 ag 400 0 01 0 4 by 0011 b A 0 015 Browse i a c Program Files HydroSoft aStar csv Browse Restore Defaults OK Cancel 56 9 7 CAL file format Note that not all the parameters included in the CAL file are needed for the calibration procedure described above Some parameters not shown here may also appear and the sequence of parameters may change depending on the firmware version Each line may also include a comment preceded by a double slash Start General Comment Serial HS991014 Config W4BOROFOSOI2 Label U South Florida 4
31. cat will only acknowledge commands that begin with that string Baud rate is the rate to which the sensor is set upon startup not necessarily the current rate Use BAUD to view or adjust the current rate The three prefix characters are used to distinguish almost all messages produced by the HydroScat 6 The Data Prefix character precedes all standard data messages see D H and T and is used by the HydroScat Windows software to identify them as such The Info Prefix precedes most informational displays including those shown in this example Error Prefix marks important warnings that demand the user s attention Cal Temp is not used in present HydroScat 6 s It is intended to serve as a reference temperature for correcting temperature related drift should such corrections be needed Depth offset and depth coefficient are used to translate raw depth data to units of meters These are not used within the HydroScat 6 firmware but are stored there for reference The maximum depth ID model S N and Config fields are described under ID section 8 3 13 44 The firmware version shows not only the sequential version number but which memory configuration it is compiled for This should match the RAM size displayed on the next line The calibration and configuration data that are unique to each HydroScat 6 are stored in nonvolatile memory in a format that has changed as more information was added in successive firmware versions
32. ching every 0 4 seconds This gives the appearance of simultaneously measuring both parameters but the actual sampling rate is limited by the time required to switch between them We recommend setting the sample period to no less than 0 5 seconds if you use time sharing If time sharing is on and the sample period is set to less than 0 5 seconds some samples will not include measurements of both parameters for the dual function channels If one sample of a parameter is skipped because of time sharing the HydroScat 6 output will repeat the last measured value of the skipped parameter giving the appearance of continuous measurements If the sample period is less than 0 3 seconds however several samples may pass without an actual measurement and zeros will appear in place of any missing measurements If you choose sampling settings that will result in missing data the HydroScat 6 will send a warning message but will not prevent the settings from taking effect If Make these settings nonvolatile is checked the settings will be stored in semi permanent memory and will remain in effect even if the internal computer is reset or all power is removed from the instrument Before logging you may wish to download and clear data from the HydroScat s memory see section 5 10 5 5 1 Noise Levels and Sampling Rates The backscattering measurement involves extremely low light levels and several factors can contribute to noticeable noise in the measu
33. concepts necessary for understanding the HydroScat s measurements The optical principles are covered in much greater detail in Instruments and Methods for Measuring the Backward Scattering Coefficient of Ocean Waters by Robert A Maffione and David R Dana Applied Optics Vol 36 No 24 20 August 1997 The HydroScat 6 has six independent channels each sensitive to a different narrow range of optical wavelengths Each channel consists of separate source and receiver optics The source produces a beam of light in the water and the detector collects a portion of the light that is scattered out of that beam by the water Each source beam originates from a light emitting diode LED selected to match the desired measurement wavelength The beam from the LED goes through a lens to adjust its divergence then through a prism that bends the beam before it enters the water The receiver consists of an identical prism that bends the field of view toward the source beam a band pass interference filter that determines the exact wavelength range of the measurement and lens that focuses the received rays onto a silicon detector The divergences of the source beam and receiver field of view the angles of the prisms and the distance between the source and receiver windows determine the range of scattering angles over which the measurement is made The HydroScat geometry results in a measurement centered on a scattering angle of 140 The fraction
34. curacy However within HydroSoft a is estimated from a priori data and b is estimated from the measured bp is calculated from the following model a A 0 06a A C 1 0 2exp y 2 440 400 exp v A 400 where the first term accounts for the contribution of chlorophyll and other factors that correlate with chlorophyll and the second term accounts for detrital material 21 a function determined empirically by Prieur and Sathyendranath and modified by Morel is the chlorophyll concentration in mg m which can be set by the user as can Voss ad400 Prior to 2 7 Kpa was reckoned including the contribution of pure water Thus it and differed considerably at different wavelengths and the value of k appropriate to each channel was included in the calibration file Starting with version 2 7 is defined to include only attenuation above and beyond that of pure water Prior to HydroSoft 2 7 the equation for absorption also included a term for pure water optical classification of coastal and oceanic waters based on specific spectral absorption curves of phytoplankton pigments dissolved organic matter and other particulate materials Limnol Oceangr 26 4 671 689 Light marine photosynthesis a spectral model with geochemical and climatological implications Prog Oceanogr 26 263 55 b is estimated from b b b b where b is the backsc
35. e tuned under software control to the frequency of another channel s source allowing them to detect fluorescence instead of backscattering If the field of view of a channel intersects the beam produced by another channel it can collect fluorescence from that channel as efficiently as it does backscattering from its own source The HydroScat 6 has two pairs of channels whose beams and fields of views cross each other see Figure 2 For example the 442 and 700 nm channels may be paired allowing the 700 nm receiver to measure either 700 nm backscattering or 700 nm fluorescence excited by the 442 nm source LED Because at any given time each receiver must be tuned to a single frequency corresponding to a single excitation source the HydroScat 6 s fluorescence measurements are not truly simultaneous with the backscatter measurements at the same wavelength However the sensor can be set to periodically set to switch between functions providing near simultaneous measurements The fluorescence function may also be turned on or off full time See section 8 3 11 for more details The fluorescence channels are not calibrated to an absolute standard so their data are reported in arbitrary units X CONNECTOR S EXACT CONFIGURATION VARIES N MAGNETIC SWITCH SHOWN IN ON POSITION SWITCH ON INDICATOR PRESSURE RELIEF VALVE 92 LIFTING EYE D P PRESSURE PORT Figure3 HydroScat 6 Rear End C
36. e card must be provided to allow communication with an 25 RS232 port If the optional PDI is purchased with the HydroScat it will be configured according to the appropriate protocol 6 4 Single Connector Configuration Starting in January 2002 HydroScat 6 s have been equipped with a single MCBH8M connector that matches that used for most other HOBI Labs instruments PIN FUNCTION Supply voltage 10 to 15 V Common RS232 Receive or RS485A RS232 Transmit or RS485B Battery charging input 24 V 1 7A MCBH8M FACE VIEW OF PINS Reserved IA U IA JW IN Reserved 8 Battery Disconnect Instruments having this configuration are supplied with a standard power data interface cable One end of the cable has an MCILSF connector that mates with the bulkhead connector The other end breaks out into a DB9 for serial communications with a computer a female barrel connector for the battery charger input and a BNC connector with binding post adapter for connecting an external supply 6 5 Dual Connector Configurations HydroScat 6 s made between mid 1998 and the beginning of 2002 used a Subconn MCBHAM mate MCILAF for power and data connections and a Subconn MCBH3M mate MCIL3F for charging and disconnecting the battery HydroScats with this connector configuration were supplied with suitable cables for the two connectors 26 Power and data connector Battery charger c
37. e not be evident to users but which can affect the reliability or endurance of the instrument 3 1 3 2 3 QUICK START Setup 1 Install HydroSoft on your computer see section 4 1 or the HydroSoft manual 2 Connect the supplied power data interface cable to the appropriate port on your computer 3 Connect the cable to the matching connector on the HydroScat 4 Run HydroSoft by selecting it on the Windows Start menu 5 Click or select Connect from the Instrument Menu 6 Click the Search button 7 After a short time HydroSoft should identify the instrument load its calibration and close the Connect dialog box 8 Select Set Date Time from the HydroScat menu 9 Click Set Time to synchronize the HydroScat clock with your computer s clock This will take several seconds Then click Close to close the Date Time dialog box Collecting Data 10 Select Sampling Options from the HydroScat menu 11 For testing purposes we recommend the following settings Sample Rate 2 per second Start Delay 0 seconds Burst mode unchecked 12 Select Plot Vs Time from the Graph menu 13 Click Sit or select Start from the HydroScat menu This will cause data to be logged in the HydroScat s logging memory as well as sent to HydroSoft 14 If no data are visible after a short time click and the plot will zoom as needed to show all data 3 3 3 4 3 5 15 To adjust the way data are displayed
38. ectory may take a number of seconds The status message in the upper left corner indicates if the directory is loaded as above or if it is in the process of loading The memory status line indicates how much of the instrument s memory is presently used You can select arbitrary groups of casts for downloading To select a contiguous group of casts click on the first item in the group then shift click on the last item or hold down the shift key while using the arrow keys To select or unselect non contiguous casts control click on them or hold down the control key while using the arrow keys to move through the directory and press the space bar to select or unselect casts Data are always collected in raw form If the Create calibrated data dat files option is checked a calibrated file will also be created for each downloaded cast The calibration currently in effect for the main data window will be applied to these data see section 5 3 for more information about calibrations Because of the way the HydroScat s memory is configured it is not possible to delete individual casts you can only erase the instrument s entire memory 5 11 Processing Downloaded Data While HydroSoft allows you to save calibrated data automatically at the time you collect or download data from a HydroScat you can also process raw data files using HydroSoft s Process Raw Files command This command also allows you to convert raw hexadecimal data to deci
39. een the instrument and the detection volume causing backscattering to be underestimated We compensate for this applying the following correction where f is uncorrected backscattering sigma corrected f can be used the equation for b above to produce sigma corrected Versions of HydroSoft prior to 2 5 used a third order polynomial approximation for sigma and the current version still uses this if the constant is not present in an instrument s calibration data 54 o K is a complicated function of the sensor s optical geometry but can be closely approximated by o K k exp where Ks is the coefficient of attenuation for light traveling from the sensor to the sensing volume and back is characteristic of the specific instrument and is included in its calibration file k is set so as to satisfy the requirement that o K 1 where Kp is the attenuation excluding that of pure water of the water in which the instrument was calibrated That is z exP kexp K onw When the calibration is performed with well filtered water is near zero and k is for practical purposes 1 at all wavelengths Since HydroScats do not make a direct measurements of attenuation their Kp is estimated from 0 45 If measurements of a and b are available they be used to calculate sigma corrections with the best possible ac
40. eese ipse 29 7 1 BATTERY CAPACITY 29 ide LOW VOLTAGE CUTOFF csesscccccceceessssececececeessnsecaecesececeesesaeseeececsesaseceeccceseneaseeeeceseenssaeeeeeeeens 30 73 CHARGING UR C EE 31 iii 7 4 5 e leaves eee Tons 32 8 DIRECT COMMUNICATION AND 8 12 4 4 0 0 tn sesto eset ense esee en seen 33 8 1 COMMU NICATION PROTOGCOL p e 33 8 2 COMMAND CONVENTIONS oss cele E ve 33 8 3 ROUTINE COMMANDS eii tetto oderit oh salon tero es eo rete a 33 8 4 SPECIAL PURPOSE COMMANDS e Udo eei ee eei eade 42 9 DATA PROCESSING REFERENCE u csccccsssscccssssccccsssscccscssccecssscccesscsccecssccscessaccessnsccecssseeeeses 47 9 1 RAW DATA BORMXATS cette tr eter eere e 47 9 2 DY RPACKETIRORMAT 2295 te ET es 47 9 3 PACKET FORMAT FIRMWARE 1 60 AND 2 202 2 10 0 50 9 4 H Uto dU EVER 51 9 5 CALCULATING B AND e tote epe Ce ee NT Cea 53 9 6 SIGMA CORRECTION eerte ee eee E Uere Ee pet roe 54 9 7 CAT
41. ei tree e eee ene a Te eT Tea ai 57 10 TROUBLESHOOT G e eee eoa a aE E 59 10 1 HYDROSCAT 6 IS UNRESPONSIVE HYDROSOFT IS UNABLE TO DETECT IT eee 59 10 2 HYDROSCAT 6 STILL DOES NOT RESPOND AFTER THE ABOVE STEPS eene 59 COMMUNICATION OK BUT EXTERNAL SWITCH DOES NOT FUNCTION AS 59 TO os dre 59 10 4 HYDROSCAT 6 BATTERIES DO NOT SUSTAIN OPERATION AS LONG AS 60 11 DEPLOYMENT CAGE OPTIONAL eere ee eere een eene sten seen esten sesso sesta 61 12 CUSTOMER SERVICE eere en eran eo eoa nnno o san vera aq epo Toe vo inse o 63 iv 1 INTRODUCTION 1 1 Overview The HydroScat 6 is a self contained instrument for measuring optical backscattering at six different wavelengths in natural waters Its unique optical geometry also provides measurements of fluorescence The HydroScat 6 includes a depth transducer rechargeable batteries a data logger with real time clock and an external switch for controlling logging The data logger supports a wide range of sampling rates as well as burst mode sampling for collection over extended periods Optional flash memory allows the data logger to hold many megabytes of data 1 2 Optics This brief overview introduces the key
42. ents are measured at the factory and stored in the instrument s memory as well as supplied in a CAL file that can be used by HydroSoft or other software The file format is described in section 9 7 The first step in processing is to convert the raw signal to the value of the volume scattering function 140 using Pu T RS c R T cal g nom with the following input variables Normalized backscatter value from HydroScat Mu from cal file kr TempCoef f in cal file T Instrument temperature calculated as shown above Tai CalTemp from cal file G Gain ratio for gain g Gainl 1 5 from cal file Room Nominal reference value Rnom from cal file The subscript here stands for uncorrected indicating that the sigma correction described in section 9 6 has not yet been applied The backscattering coefficient b is estimated from 140 using method described in Instruments and Methods for Measuring the Backward Scattering Coefficient of Ocean Waters by Robert A Maffione and David R Dana Applied Optics Vol 36 No 24 20 August 1997 according to the following expression by 22 pp 140 8 140 day with the following additional inputs X bb Constant of proportionality between 140 and b for particle scattering The default value is appropriate for most cases but can be changed in the backscattering parameters dialog box shown below In cal files the value 2775 is stored with the
43. ernal 10V to 15V supply 2 internal battery 3 battery charger Any combination of these source may be safely connected simultaneously Power for operating the instrument will be drawn from the source with the highest voltage but the batteries are charged only through the separate charging input The external power input can be used to connect additional battery packs to the HydroScat If you plan to use the magnetic switch to activate logging while powering the instrument from an external source see the important note in section 5 9 1 Whereas the operating voltage is limited to a maximum safe level of 15V at a maximum power level of 3W the charging voltage must be regulated at 24V and capable of supplying up to 1 8A of current The HydroScat 6 is supplied with an appropriate charging supply See section 7 for more details about charging the internal batteries 6 2 Battery Disconnect Shorting the battery disconnect pin to the common pin electronically disconnects the internal batteries from the HydroScat circuitry Note that disconnecting the batteries will cause the loss of any data in RAM Data stored in flash memory for HydroScats so equipped will not be affected 6 3 Data Connections HydroScats can be configured to use either RS232 or RS485 protocols for communication In the RS232 configuration the HydroScat can communicate directly through a standard computer serial port In the RS485 configuration a converter or interfac
44. eters For shorter sample periods some samples will not include measurements of both parameters If one sample of a parameter is skipped because of time sharing the sensor will repeat the last measured value If the sample period is short enough that several samples pass without an actual measurement zeros will appear in place of the missing measurements When you enter a combination of sample period entered with the LOG command and FL mode that will lead to skipped measurements the sensor will provide a warning message but will not prevent the settings from taking effect The two fluorescence channels need not operate in the same mode To specifically address one of the fluorescence channels you can type its full name as the command For example 1 510 1 turns on 510 without affecting f1671 NOTE Changes you make with the FL command are not saved when power is disconnected from the sensor unless you first use the STOREFL command section 8 3 21 8 3 12 H Transmits a hexadecimal packet of housekeeping information See section 9 4 for details of the packet format 8 3 13 ID ID displays identifying information about the sensor This information can only be set at the factory except for the address which can be set with the GCF command section 8 4 6 It replies in this format Identification Model 56 S N HS97074 Config W1B2R112P2 ID Hobi One Address Maximum Depth 200 m Firmware 1
45. fter a START command power on or magnetic switch activation before the first sample is logged A nonzero sleepOnMemFull value indicates that the sensor will stop logging and go into a low power sleep when the log memory fills Autostart if non zero indicates that logging will start with the given delay automatically when power is applied to the sensor Autostart applies primarily to HydroScats without batteries those with batteries are usually powered continuously even in sleep mode The burst mode parameters are described under the BURST command although they can also be modified using LOG The reply to the LOG command shows the settings of all the applicable parameters Sampling and Logging Parameters Log Period 1 seconds Start delay 60 seconds Sleep when memory full 1 Start on power up 0 Burst mode 1 ON 39 Warmup time 5 seconds Burst duration 15 seconds Burst cycle 10 minutes Total duration 0 hours not in effect NOTE Changes you make to the log parameters remain in effect only as long as the sensor is powered unless you make them permanent with the STORELOG command section 8 3 22 8 3 15 RAM Displays information about the log memory in the following form 339960 1017856 bytes 33 used in log RAM 710059 29976 packets logged First packet logged 05 01 97 13 40 42 Last packet logged 05 01 97 14 28 02 The first line shows how many bytes are used and the total memory in the s
46. giving the calibrated temperature a range of 10 to 41 C 9 2 10 Error Each bit in the one byte error code corresponds to a particular error condition weight condition 1 high background 2 high signal 4 reference out of range not yet implemented 8 temperature out of range not yet implemented 16 primary voltage out of range not yet implemented 32 battery voltage out of range 64 log memory full 128 undefined 49 9 2 11 Checksum Checksum is the least significant byte of the unsigned sum of all the ASCII bytes preceding the checksum in the packet not including the packet flag 9 2 12 Terminator This packet and all other transmissions are terminated with a carriage return and line feed 9 3 Packet Format firmware 1 60 and later The T packet is identical to the D packet except that the resolution of the time value is extended by 2 hex digits The added digits indicate the fractional time in hundredths of seconds In the example below the fractional time of 1A indicates 0 26 seconds Fractional time values greater than 99 decimal 63 hex are undefined 9 3 1 Example T Packet T346A023C1A055613CC160615DE13232034FB24F9525555550006488700B4 CR LF 9 3 2 Packet Structure Parameter Type ASCII ASCII Example Bytes PacketFlag 1 Packet ID char T Time signed 8 346A023Ci Fractional 2 1A Time Snort 0556 Snorm2 13 Snorm3 1606
47. h brief messages via the communications port For example Charge starting e Trickle charging e Starting fast charge e Fast charge terminated e Charger disconnected The battery can only be fast charged if its temperature is between 10 C and 45 C When the charging supply is first connected a trickle current flows while the charger checks the temperature of the battery If the temperature is appropriate fast charging will begin within 30 seconds If not the trickle charge will continue until the temperature comes within range Note that the battery temperature may change very slowly compared to the HydroScat 6 s case temperature A completely discharged battery will reach full charge after a fast charge of about three hours Partial charges require proportionately less time Ideally fast charge will continue until full charge is detected as indicated by a drop in voltage or a rapid rise in temperature Fast charge will also terminate 31 if the temperature goes out of the safe range Note that it is normal for the battery temperature to gradually rise during charging If a charge is started when the temperature is near the high limit the fast charge may terminate prematurely due to this normal rise After the termination of a fast charge the charger goes into a top off mode during which it pulses the fast current for roughly two seconds out of every 30 This mode lasts a maximum of two and a half hou
48. he channels are not completely independent with regard to gain settings and gain settings 1 and 2 the lowest behave differently from the higher three gains Gains 1 and 2 are ordinarily only needed during calibration procedures using a highly reflective target If any channel is set to a gain of 3 or higher gain settings 1 and 2 the lowest will not take effect In order to use gain settings 1 and 2 all channels must be set to gain 1 or 2 Also setting a channel s gain to 1 or 2 will disable automatic gain control for that channel Reply gains 54555500 Gain 15 reported as zero when a channel is disabled For example channels 7 and 8 are reserved for reporting fluorescence measurements and are disabled by default 43 8 4 6 GCF address Baudrate GCF stands for global configuration This command displays and sets certain parameters that pertain to the HydroScat 6 as a whole Note that not all the parameters displayed can be set with this command Reply Global Configuration Address Baud Rate 9600 Data prefix Info prefix Error prefix Cal Temp 0 000000 Depth Offset 14 1 Depth Coefficient 0 0089 Maximum Depth 200 m ID Institution Model HS6 S N 597074 Config W1BOR11I2P2 Firmware 1 10 256K RAM size 256K Config Version 2 Cal Time 10 01 97 11 03 41 The address should normally be set to If itis set to any other character or string the HydroS
49. ite nnne enn 18 5 8 POA MEMORY GCAPACTEY diee ces feret entitled 18 5 9 USING THE MAGNETIC SWITCH 1 61 01166 eet E ea et ea pena E AN aede 18 5 10 DOWNLOADING LOGGED DATA cccsessscesececeessnsececececsenssuauececececsenssaeceeceseseseaseeceeeesensaeeeeceeens 20 5 11 PROCESSING DOWNLOADED 2 21 20 00 00000000000000000 a 21 5 12 RAW DATA BIEEEORMAT wie 23 5 13 CALIBRATED FEILE FORMAT iret ert e Ere uk 23 6 ELECTRICAL 8 1 1 a sa se see tete sn sese ses eese suene ses esse see 25 6 1 POWER INPUTS 5 retirer teer reete etre peste pv e toa ede ve e ARE TES 25 6 2 BATTERY DISCONNECT 5255 ard ree biete vie ORE e E bs 25 6 3 0 25 6 4 SINGLE CONNECTOR CONFIGURATION 2 2 1 2200000 000000000000000 26 6 5 DUAL CONNECTOR 8 2 0 010 000000000000000000000000 26 6 6 EARLY DUAL CONNECTOR 2 400000 010100000000000000 27 T INTERNALD BATTERY erue po eeu Pepe ed uve eges
50. le casts If no argument is given transmits the entire contents of memory This command does not change the contents of the log memory Reply If a valid cast number is specified raw data packets in the same form as produced by the sensor in real time You can interrupt a download in progress without affecting the contents of memory by sending a control C character to the HydroScat Because RS485 cannot support simultaneous two way transmission this works only on sensors with RS232 interfaces 8 3 11 FL on FL controls the function of the two dual function backscattering and fluorescence channels of the HydroScat 6 also see sections 1 4 and 5 5 Whether or not you include an argument FL reports the configuration of the fluorescence channels Reply 1510 excitation bb470 receiver bb510 status 1 1510 on bb470 off 37 1671 excitation bb442 receiver bb671 status 0 f1671 on bb671 off The argument on is a numeric value the same as the status value shown above indicating which function is active The value 1 turns on the fluorescence full time 0 zero turns fluorescence off leaving backscattering on The value 2 turns on time sharing causing the backscattering and fluorescence functions to alternate In the time sharing mode the function changes every 0 4 seconds Note that this means the sensor will require somewhat more than 0 4 seconds to make a complete measurement of all param
51. ly you should not need to modify calibration data for an instrument and the fields in the Calibration dialog box are locked to discourage casual changes However you can unlock most fields by clicking on the lock icon in the dialog box Because correct calibration files are critical to the accuracy of your data use care when modifying them To reduce confusion we encourage you to enter a description in the comment field provided of any changes you make To save a copy of the currently loaded calibration select Save Calibration from the File menu 5 4 Connecting To communicate with a HydroScat HydroSoft must open the appropriate computer port at the correct baud rate The following dialog box allows you to control this process 14 5 4 1 Connection Dialog Box Connect To Instrument x Status No Connection Com Port Baud Rate Instrument Type 1 9600 unknown Load Calibration From Instrument B Search Close This dialog box appears each time you e select Connect from the Instrument menu e click on the Connect button in a data window e attempt an operation that requires a connection if a connection has not yet been established 5 4 2 Manual Connection If you click the Connect button HydroSoft will open the currently selected port at the selected baud rate Normally you need not select an instrument type because HydroSoft will always request identification information from the inst
52. m CR ReOf where Sig and Ref are the raw signal and LED reference measurements SigOff and RefOff are the signal and reference measured during the time when the LED is off Rnom and SigDark are parameters from the HydroScat s calibration record Snorm is a 16 bit signed integer Snorm is used to calculate backscattering as shown in section 9 5 48 9 2 7 Gain Status There is one 4 bit gain status value for each of the optical data channels The three LSB s comprise a gain setting and the MSB indicates status A gain setting of zero indicates that the channel is disabled and its data should be ignored Gains of 1 to 5 are used to select one of five coefficients to be applied to Snorm Gains 6 and 7 are undefined The status bit is zero under normal conditions The status bit for a channel may be set to 1 if the HydroScat detects a condition that may affect the quality of the data on that channel However a status value of 1 does not necessarily indicate invalid data 9 2 8 DepthRaw DepthRaw is reported as a signed 16 bit integer The depth in meters is calculated by depth m DepthRaw depthCal depthOff The values of depthCal and depthOff are specified in the calibration file provided with each instrument 9 2 9 TempRaw TempRaw indicates the HydroScat s internal temperature actual temperature is calculated by Temp C TempRaw 5 10 Note that TempRaw is an unsigned byte with a range of 0 to 255
53. mal form without calibrating them When you select Process Raw Files the following dialog box appears 21 Process Raw Data Files Processing Make Calibrated Files C Make Raw Decimal Files Calibration File D Manufacturing Products HScats HS6 Individual Instruments HS33 IF Browse Raw Files to Process Directory containing source files al Instruments HS33 IRD2X2004 9 Service Cal Preservice Cal 2004 101 File name filter Eligible Files raw H5020733 2004 10 11 dKtime an4 1 Select All H5S020733 2004 10 11 dktime 4 2 H5020733 2004 10 11 dktime 95 1 Show only files rnatching 5020733 2004 10 11 9 9 5 2 Select None calibration file H5020733 2004 10 11 dktime gn5 2 ER H5020733 2004 10 11 dktime_gn5_4 Use Shift click to select HS020733 2004 10 11 dk_1 raw groups of files HS020733 2004 10 11 dk_2 raw ei uere end P H5020733 2004 10 11 dk 3 raw H5020733 2004 10 11 gn raw H5020733 2004 10 11 time raw Save Processed Data Files To C Documents and Settings Administrator My Documents Browse Same location as raw files Process Close 5 11 1 Making Calibrated Data Files When Make Calibrated Files is selected you need to specify a calibration file to be used see section 5 3 for more information about calibration files You can type the path and name of the file directly or use the Browse button to open an Open File dialog box You must also select the file or files
54. must specify one of the standard rates exactly When the HydroScat states a baud rate it shows both the nominal and actual values The deviation in actual baud rates is well within the acceptable tolerances for communication with a computer Reply if no rate specified 42 Baud rate 9583 9600 Reply if rate is 19200 Changing rate to 19166 19200 8 4 2 AGAIN channel auto Turns automatic gain control on if auto 1s nonzero or off if auto is zero The channel argument specifies to which channel the auto argument applies The channels are numbered 1 through 8 Setting channel to zero causes the auto argument to apply to all channels Note that automatic gain control only works for gain settings of 3 4 and 5 see the gain command Even if it is enabled automatic gain control will have no effect if the gain is set to 1 or 2 Reply for the default setting of autogain active for all channels autogains 11111111 8 4 3 ECHOOFF Turns off character echo so that characters received by the HydroScat are not automatically retransmitted to the computer This is the HydroScat s default setting 8 4 4 ECHOON Turns on character echo That is the HydroScat will automatically retransmit every character it receives back to the computer Echo 15 off by default 8 4 5 GAlN channel gain Sets the given channel 1 through 8 to the given gain 1 through 5 If channel is zero all channels are set to the given gain T
55. ng supply is connected 30 7 3 Charging The HydroScat 6 contains a sophisticated three stage charger that fully recharges the battery in less than 3 hours It also closely monitors the cumulative charging and discharging of the battery to allow tracking of battery capacity The HydroScat 6 includes an external power supply that converts 95 to 250 VAC to the 24 1 VDC required by the charging circuitry Note that this supply is not the same as that contained in the optional Power Data Interface PDI which does not provide charging power to the battery The internal charger regulates the current from the charging supply and selects either a low trickle current a high fast charging current or a pulsed top off current depending on the temperature and state of charge of the battery Charging starts whenever the charging supply is connected This also causes the HydroScat 6 to wake if it is asleep see section 8 3 16 and to halt any data collection in progress Then and throughout charging the six beams of the sensor flash in one of two patterns to indicate the charge status e Fast always one color on changing colors at 3 Hz Trickle or top off one quick cycle through the colors every 5 seconds This permits one to monitor the charging without requiring direct communication to the sensor However it is also possible if connected to communicate and send commands The HydroScat 6 also announces changes in charging status wit
56. o control whether housekeeping data will be included in the file in addition to the primary optical data 5 12 Raw Data File Format HydroSoft names raw data files with the extension Raw files start with a header like the following Header HydroSoftVersion 2 02 CreationDate 02 12 01 23 00 55 FileType raw DeviceType HydroScat 6 DataSource HydroScat 6 CalSource D Program Files HOBI Labs temp cal Serial HS000123 Config S2B3 EndHeader Future versions of HydroSoft may include additional information between the Header and EndHeader markers In any case everything following the end marker is included in the exact form in which it was received from the HydroScat For information on the raw data formats see section 9 5 13 Calibrated Data File Format HydroSoft normally names calibrated data files with the extension DAT Calibrated data files start with a header like the following Header HydroSoftVersion 2 02 CreationDate 02 12 01 23 28 42 FileType dat DeviceType HydroScat 6 DataSource Instrument Cast 3 23 CalSource D Program Files HOBI Labs temp cal Serial HS00001 Config S2B3 SigmaParams ad400 01 aStarFile D Program Files HOBI Labs aStar csv awFile D Program Files HOBI Labs aw csv bbTildeValue 015 1 gammad 011 gammay 014 Channels bb440 bb676 1676 ColumnHeadings Time Depth bb440 bb676 1676 bb440uncorr bb676uncorr f1676unco
57. o its off position log memory filling up e battery voltage falling too low scheduled sleep during burst mode logging 8 3 18 START delay Causes the HydroScat mark the beginning of a new cast in log memory and to begin logging and transmitting data according to the parameters set with the LOG or BURST command Logging will start after delay seconds or if no delay is specified after the start delay specified by the LOG command START has no effect if the HydroScat is already logging Reply Sampling starts in delay seconds 8 3 19 STARTNOLOG delay added in firmware 1 80 Identical to START except that data collected will not be logged in internal memory 8 3 20 STOP Causes the HydroScat to immediately cease logging and transmitting data Also marks the end of the current cast if any in the log directory Reply Sampling stopped 8 3 21 STOREFL Stores the current settings of the fluorescence channels see the FL command on page 21 in non volatile memory so they will remain in effect even when power is removed from the sensor Reply Storing OK 8 3 22 STORELOG Stores the current settings of the log parameters see the LOG command on page 22 in non volatile memory so that they will remain in effect even when power is removed from the sensor 41 Reply Storing OK 8 3 23 T Transmits a packet of hexadecimal format See section 9 3 for details of the data format 8 3 24
58. oSoft is HOBI Labs Windows based software for communicating with HydroScats as well as other instruments Instructions in this manual assume you are using HydroSoft to communicate with your HydroScat and cover its primary functions You may wish to consult the separate HydroSoft manual for a more complete description and details 4 1 Installing HydroSoft HydroSoft is supplied on a CD ROM with new instruments and can be supplied on floppy disks by request We also recommend you visit our web site www hobilabs com to check for downloadable updates to HydroSoft It is installed using a procedure that is familiar to most Windows users 1 Run InstallHydroSoft exe from CD ROM or from your computer if you have received it through the internet 2 Click the Next button in the installer s Welcome dialog box 3 Decide whether you would like the HydroSoft application stored in the default directory shown normally c program files HOBI Labs If not click the Browse button to select a different directory or type the name of a new directory you would like to create 4 Click Next to start the installation 5 When the installation is complete click Finish to exit It is not normally necessary to reboot your computer unless the installer program explicitly instructs you to 4 2 Removing HydroSoft 1 From the Start menu select Settings then Control Panel 2 Double click on the Add Remove Pr
59. ograms icon 3 Select HydroSoft from the list of programs 4 Click the Add remove button OR 1 Open the directory into which you installed HydroSoft 2 Double click on the unwise exe icon which runs the uninstaller 11 5 COLLECTING AND HANDLING DATA 5 1 Primary Data The primary data reported in every sample are e date and time e raw scattering for each channel e the gain of each scattering channel e pressure and e internal instrument temperature 5 2 Housekeeping Data HydroScats record certain housekeeping parameters that are not required for normal data processing but can be valuable for troubleshooting and for evaluating the health of the sensor They are e battery and external supply voltages background radiance on the detectors in arbitrary units e reference measurements of the LED outputs and e signal offsets Normally the housekeeping data are logged at one tenth the rate of the main data That is every ten samples are followed by one housekeeping sample 5 3 Calibration Data HydroScats data are transmitted in a partially processed hexadecimal form which must be converted to calibrated units The coefficients required for this conversion are unique to each instrument and may be revised from time to time when the instrument is recalibrated HydroSoft requires an appropriate calibration to be loaded before it can plot or store calibrated data from an instrument or raw data file
60. onnector MCBHAM Face view of pins Face view of pins Pin 4 V suppl Pin 1 RS232 M a xmit Pin 3 Charging _ voltage 24V 3 4 Pin 1 Common 3 2 Pin 3 Orn 2 Common 2 Battery disable 6 6 Early Dual Connector Configuration HydroScat 6 s manufactured before mid 1998 had an XSG 4 PBCLM connector for power and data and XSG 3 PBCLM for battery connections The pin number assignments for these connectors were the same as for the MCBH connectors used in later instruments 27 7 INTERNAL BATTERY HydroScats manufactured since December 1998 are equipped with an internal rechargeable battery except upon special request Earlier instruments may have had a battery added as an option If you are not sure whether a HydroScat has an internal battery connect to it and use the command see section 8 4 6 The battery provides capacity sufficient for a day of intensive data collection With intermittent sampling and proper use of the HydroScat s low power modes it is possible to operate for days or weeks between charges 7 1 Battery Capacity The actual capacity of the battery depends on the temperature at which it is charged stored and discharged Charging and storage at temperatures of 20 C or less improve capacity On the other hand low temperatures during discharge lower the realized capacity Peak capacity for a battery charged and discharged at
61. pecified by Start Delay then data will be logged according to the given Sample Period If burst mode is on the sampling continues until the Burst Length has elapsed at which time the sensor goes into its low power sleep state The bursts repeat according to the period set by Burst Interval At the beginning of each burst the HydroScat will wait for the number of seconds specified in Burst Warmup before 16 collecting its first sample Whether or not burst mode is on sampling stops upon receipt of a software stop command when the external switch is turned off or when the battery becomes exhausted In the example above the burst mode parameters are inactive because burst mode is not on To edit the burst mode parameters you must first check the Burst Mode On option If Start on power up is checked the HydroScat will begin logging each time power is applied Note however that this setting is only relevant after all power sources including internal batteries are turned off For HydroScats with internal batteries i e most HydroScats this only affects what happens after you intentionally disable the batteries see section 7 4 The bb fluorescence sharing settings control the two dual function channels of the HydroScat 6 also see sections 1 4 and 8 3 11 These channels can either measure backscattering or fluorescence or can time share between them In the time share mode they alternate between backscattering and fluorescence swit
62. plug designated by a red handle into the HydroScat 6 for 10 seconds If the special plug is not available directly short together the battery disconnect and common pins on the bulkhead detector see connector diagrams in section 6 Attempt to connect with HydroSoft Communication OK but external switch does not function as expected If you are powering the sensor from an external source see the note in section 5 9 1 If switch operation is intermittent look for signs of corrosion around the external actuator If corrosion is evident the magnet may be damaged 59 10 4 HydroScat 6 batteries do not sustain operation as long as expected Check for damage to the charger or charging cable e If batteries do not respond to charging or their endurance is very short less than an hour do not attempt to compensate with frequent or prolonged charging Drastically reduced capacity indicates a battery failure and prolonged charging of a faulty battery can damage the instrument and possibly create hazardous venting from the batteries Contact HOBI Labs about repairs 60 11 DEPLOYMENT CAGE OPTIONAL To safely use the deployment cage be sure to l Secure all screws on the clamps around the instrument Tighten with V or 13mm wrenches Connect a safety line from the eye on the HydroScat 6 end cap to the ring on the profiling cage Position the HydroScat 6 so its face is 5 to 10 cm from the bottom of
63. rements especially in clear water However noise in the measurements is unbiased and uncertainty can be reduced by averaging samples together or equivalently lowering the instrument s sampling rate conditions with low background light at a 17 sampling rate of 1 Hz the RMS noise level is typically from about 0 00002 mz to 0 0002 m l depending on wavelength High background light levels can introduce shot noise that degrades these figures In many circumstances natural variability exceeds the measurement noise In water containing significant numbers of very large particles even schools of fish the data may show a background scattering level punctuated by spikes of increased scattering as individual large particles pass through the sampling volume Depending on your application you may or may not wish to include such spikes in averaged measurements Higher sampling rates preserve the option of evaluating the character of the data before averaging or other processing 5 6 Setting the HydroScat s Real Time Clock Although it is not necessary for the sensor s operation you may wish to set the real time clock before logging Select Set Date Time from the HydroScat menu Click Set Time to synchronize the HydroScat clock with your computer s clock If you wish to set the clock to a different time reference select the Set Manually option and enter the correct date and time before clicking Set Time It takes several seconds for
64. rge current is about 0 32 A The maximum charge current is about 2 5A Present dschg 0 21 AHr 2 4 WHr The total charge and energy drawn from the battery since the end of the last charge This is your best indication of how close you are to needing a charge After a full charge you will be able to get roughly 60 WHr out of the battery depending on the temperature at which it was charged and discharged In this case only 2 4 WHr a small fraction of the total capacity has been used Ifa charge is in progress this will indicate the energy drawn before the start of the present charge and the label will change to previous dschg Last charge 1 23 AHr 17 4 WHr The total charge and energy put into the battery during the previous charge or if a charge is in progress the present charge the label will change to reflect this The charge required for a completely discharged battery may be as much as 80 WHr This is higher than the maximum discharge capacity because of inefficiencies in the electro chemical process of charging the batteries In this example the energy is fairly low presumably because the battery was mostly charged before the charge was begun Charge Start none If a charge is in progress this will show the date and time according to the internal clock at which it started Duration 16 min fast 114 min total The duration of the present or previous charge In this case the fast charge lasted only 16 minutes which indica
65. routine maintenance performed at HOBI Labs In older HydroScat 6 s without oil reservoirs the pressure transducer is located under a black plastic cap flush with the rear end cap with four small drain holes see Figure 3 on page 4 Rinse the sensor with fresh water by gently spraying it into the drain holes 2 5 Connectors Occasionally apply silicone lubricant to the connector pins The connectors should mate smoothly without great force Well lubricated connectors also disconnect fairly easily so use the connector locking sleeves during deployment 2 6 Mounting and Deployment The HydroScat can be suspended vertically from the metal eye on the connector end cap or strapped to another support If mounting it to another structure protect the finish on the case from direct metal contact See section 11 for information about the optional welded cage supplied by HOBI Labs To ensure that the HydroScat does not detect reflections from any objects keep a 30 degree cone in front of the windows clear for at least 1 meter Even objects that appear very non reflective or are well out of the nominal sampling volume can create substantial offsets in the backscattering measurement You may find you can violate these strict limits but you should verify by experiment that the instrument s readings are not elevated if you do so It is usually preferable for the sensor to face directly down the water to minimize the effect of background illumin
66. rr Data 36872 9715856481 29 388 0 1 5536 04 0 0 1 5536 04 0 Future versions of HydroSoft may include additional information between the Header and Data markers The lines following SigmaParams are the parameters used for sigma correction of the calibrated backscattering described in section 9 6 The line following columnHeadings names the parameters included in the calibrated data lines Future HydroSoft files may include additional column headings and data parameters but if so the parameters shown here will remain in the same order Times are stored as double precision real numbers corresponding to the number of days since midnight January 1 1900 This is the native format of dates and times in Microsoft Excel Depth is in meters is in inverse meters and is shown first in its sigma corrected form then in uncorrected form 140 values with and without sigma correction are also included if the include beta in dat files option is selected in the Backscattering Parameters dialog section 9 5 24 6 ELECTRICAL CONNECTIONS HydroScat 6 s have been produced with three different connector configurations depending on their date of manufacture The connection functions as described below have remained the same in each configuration See the following sections for the exact connector specifications and pin assignments 6 1 Power Inputs A HydroScat 6 can be powered from three sources 1 ext
67. rs after which it switches to the low trickle current Both trickle and top off modes are referred to as slow charge in the HydroScat 6 s status messages While it is safe to continue trickle charging indefinitely repeated prolonged charges can eventually degrade capacity Under normal circumstances we recommend you disconnect the charging supply within 8 hours after a full charge is completed Also avoid charging the battery much more frequently than necessary Even with near constant use charging once or twice a day should be adequate It is best to allow the battery to discharge substantially between charges IMPORTANT NOTE It is possible to damage the battery and to create a safety hazard by repeatedly initiating new charges when the battery is fully charged Do not attempt to top off the battery by forcing a new fast charge after a normal charge termination 7 4 Battery Disconnect The internal battery can be disconnected from the circuitry by shorting the appropriate pin on the bulkhead connector for the connector pin assignments see section 6 to ground using the special dummy plug supplied This special plug distinguished by a red handle must be removed and replaced with the black generic dummy plug to permit battery powered operation The battery disconnect capability is useful to prevent loading of the batteries during long periods of storage or if it is necessary to reset the instrument s internal computer 32
68. rument If it receives a reply sufficient to identify the instrument it will proceed with the connection and close the dialog box If not it will notify you and ask whether to open the connection anyway In you instruct it to it will proceed on the assumption that an instrument of the type you designate is connected 5 4 3 Search Connection If you click Search HydroSoft will ignore the selected port and baud rate and attempt a connection to each port at each baud rate from 4800 to 57600 until it receives valid identifying information from an instrument The dialog box will automatically close if a valid connection is found 5 4 4 Load Calibration From Instrument Option If Load Calibration From Instrument is checked at the time an instrument is connected HydroSoft will prompt the instrument to transmit the calibration information stored in the instrument s memory This will override the currently selected calibration file if any See section 5 3 for more information about calibration files 15 5 5 Logging Setup HydroScats can be programmed to collect data continuously at rates from 0 1 Hz to 10 Hz or intermittently to allow autonomous logging for long periods In HydroSoft you can set these parameters in the following dialog box which appears when you select Sampling Options from the HydroScat menu Sampling Options x Basic Sampling 550nm bb fluorescence sharing Sample Rate per second C bbonly
69. t 7 seconds at the sensor s internal 100 Hz rate and 11 samples were averaged to produce the offset figures Since the LEDs must be turned off to measure offsets only about 5 of the sensor s time is devoted to them and the number of offsets averaged is usually smaller than the number of signals In general the number of samples differs slightly from channel to channel The sample quantities shown are averaged over all channels 45 The next eight lines show the name of each channel followed by its signal signal offset reference reference offset background radiance and normalized signal SNorm The background radiance is usually small in laboratory conditions The background saturates at approximately 85 on some sensors and 120 on others depending on which components are installed on the motherboard SNorm is the normalized signal sent in the standard data packets see section 9 2 6 Itis calculated by S R Sig SigOff SigDark norm nom Ref RefOff where Rnom and SigDark are parameters from the channel calibration record Snorm is a 16 bit signed integer Note that in this case the fluorescence channels are turned off so their data are all zero The next line shows the gain settings of all the channels Gains may range from 1 the lowest to 5 The last two are shown in parentheses to show that channels 7 and 8 were turned off in this instance The depth value shown is in raw digital counts The temperature shown
70. ta packet described below contains the primary optical and supporting data for routine data collection The packet which was introduced in firmware version 1 60 is identical to the D packet except that it includes higher resolution time values packets contain housekeeping data that are not needed for normal data processing but provide extra information that could be useful for trouble shooting It is advisable to save all the raw data in case any special post processing is needed For troubleshooting purposes you can view raw data in decimal form by using the X command section 8 4 7 Packets consist of ASCII characters Numbers are represented in hexadecimal notation Signed numbers are in 2 s complement format Transmissions always end with carriage return and line feed characters 9 2 Packet Format 9 2 1 Example D Packet D346A023C055613CC160615DE13232034FB24F952555555000648870042 CR LF 9 2 2 Packet Structure Parameter Type ASCII ASCII Bytes Example Packet Flag Po PacetiD da D Time signed HHHHHHHH 8 346 023 Snomi signed HHHH 4 0556 Snom2 signed 4 ncc Snom3 signed HHHH 4 1606 Snom4 signed HHHH 4 150 sinea HHHH 4 1323 Snom soned 4 2034 Snorm7 signed 4 Fe Snom8 signed 4 Fo 1 5 Gai Statusa 1 Gain Status3_ nibble 1 Gain Status
71. tes the batteries were near full charge before the charge started The charger was unplugged 114 minutes after the charge started Peak voltage 15 82 v at 16 min 35 The highest voltage reached during the present or previous charge and how long after the start of charge it was reached Fast end voltage 14 45 The voltage at the time the previous fast charge ended Charges 10 How many times the batteries have been charged since the sensor s final assembly Total Charge 80 3 Ahr 820 0 Whr The cumulative charge and energy of all recorded charges Total dischg 43 2 Ahr 452 4 Whr The cumulative charge and energy of all recorded discharges Note that the total discharge will always be less than the total charge because the charging process is not perfectly efficient and also because the batteries can safely tolerate a considerable amount of overcharging However if the cumulative charge is more than 3 times the cumulative discharge after a large number of charges you should considering reducing the frequency and duration of charges 8 3 5 CLEARRAM Erases the contents of the log memory Before proceeding displays the memory status the same information as displayed by the ram command and asks for confirmation Reply 339960 101 7856 bytes 33 used log RAM 710059 29976 packets logged First packet logged 05 01 97 13 40 42 Last packet logged 05 01 97 14 28 02 ERASE ALL DATA IN RAM Y N N ee 22 Press
72. the cage Safety Line Clamping Screws 61 12 CUSTOMER SERVICE If your HydroScat 6 needs to be returned to HOBI Labs for repair maintenance calibration contact Labs customer service serviceWhobilabs com or go to the support section at www hobilabs com with the following information at hand Instrument Serial Number Reason for return Method of return Federal Express United Parcel Service etc Point of contact Date needed Delivery address HOBI Labs will provide you with a returned material authorization RMA number so that your instrument will be properly identified when we receive it PLEASE DO NOT RETURN ANY EQUIPMENT TO HOBI LABS WITHOUT AN RMA NUMBER As soon as possible after receiving the instrument HOBI Labs will inspect it and provide you with an estimated cost for required or recommended repairs if any Repairs will not be started until you approve the cost estimate and turnaround time For technical support or questions about your instrument contact our technical support department at support hobilabs com or consult the support section of www hobilabs com 63
73. you wish to process using the familiar browse controls The list in the center right of the dialog box shows those files that are contained in the drive and directory you specify and whose names match the File name filter you specify If Show only files matching calibration file is checked as it is by default HydroSoft will check the contents of the files and list only those that contain data from the instrument type and serial number specified by the selected calibration file You can select a single file or an arbitrary group of files from the list Select a contiguous group of files by shift clicking and select or deselect individual files by Ctrl clicking Once you start processing all the selected files will be processed The processed files will use the same base names as the source files with their extensions set to They will be saved in the directory you specify If 22 you wish to save them in the same directory as the raw files from which they are generated you can avoid having to select that directory manually by checking the Same location as raw files option 5 11 2 Making Raw Decimal Files The process for making raw decimal files is identical to that described above except that there is no need for a calibration file Controls relating to the calibration file will thus be disabled When you select the Make Raw Decimal Files option an additional Include Housekeeping checkbox will appear allowing you t
74. ystem The second line shows how many packets samples are stored and the approximately maximum number of packets that can be stored If the memory is empty the last two lines are omitted The accuracy of the dates and times presented depends on the HydroScat s real time clock being set accurately See DATE 8 3 8 and TIME 8 3 24 8 3 16 SLEEP secs The SLEEP command causes the HydroScat to immediately cease any data collection and go into a low power sleeping state this state the current consumption is reduced to a level similar to the battery s self discharge rate The secs argument if included specifies the duration of the sleep in seconds If no duration is specified the sleep interval defaults to an essentially infinite 200 000 000 seconds about six years The HydroScat 6 wakes from its sleep when e the specified number of seconds has passed or e itreceives characters through its communication port the charging supply is connected to the battery charger or e the magnetic switch is moved to position The HydroScat 6 wakes automatically when the battery charging supply is connected so that the internal computer can monitor charging and signal charge status with the LEDs 40 8 3 17 SLEEPINFO SLEEPINFO displays the time and cause of the HydroScat s last sleep and of it subsequent waking Possible causes of sleep include e receipt of the SLEEP command movement of the magnetic switch t

HydroScat-6 User's Manual - Remote Sensing and Satellite

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