DSTS 4A/3 operators manual
Contents
1. 5 MENU STRUCTURE OVERVIEW The MODE key is used to select different menu screens During the time the MODE Switch is held down a help screen will be displayed It will provide information regarding the menu that will appear when the switch is released When you have read the help screen release the switch to go directly to the menu The menu you have selected may redefine some of the keys Forexample the FREQ switch is redefined as FT inthe CAL menu screen To return to the Top Menu just lift the MODE switch one or more times This returns the DSTS 4A to normal operation Study the MENU STRUCTURE in section 5 and the operation will become clear 5 0 1 SPEED SETTING FREQ WIDTH AND DEPTH Example While holding down the DEPTH switch press the MODE switch down for about 2 second and release it The units digit will start changing Press the MODE down twice more and the hundreds digit starts changing This works with the frequency and width switches too Each time the MODE switch is momentarily pushed down the next digit to the left will begin changing To set the least significant digit momentarily release all switches and start again Please note that the depth width and frequency can still be set as in previous versions of the software i e press and hold FREQ WIDTH or DEPTH and the least significant digit will change ten times then the next digit to the left will change ten times then the next etc DSTS 4A OPERATORS MAN UAL Hardware2. 20 feet no echo will show as itis off range 9 3 2 IS THE DSTS 4A IN THE AUTO WIDTH TRACK MODE Some depth sounders will not lock on to the echo if the DSTS 4A is notin the AUTO PULSE width tracking mode Some sounders send a Series of pulses with different widths and will reject the echo from the DSTS 4A if it is set to a fixed width Lift and release the FREQ and WIDTH switches to put the DSTS 4A in the width tracking mode Increase the REPLY LEVEL to the maximum After the sounder locks on to the echo reduce the REPLY LEVEL You may have to repeat the above steps if the depth is quickly changed by a large amount 9 4 INCONSISTENT FREQUENCY READINGS Certain conditions will cause inconsistant or incorrect frequency readings 9 4 0 1 If you are measuring a dual frequency depth sounder be sure to set it for single frequency operation 9 4 0 2 Try using a longer input pulse width This can usually be done by increasing the depth range of the DUT Device Under Test or by rotating Suppression or discrimination controls on the DUT 9 4 0 3 Change the DSTS 4A load switch to a different impedance range Lowering the load impedance will drop the Q of the tank circuit and the effect of the pulse ringing or chirp on the frequency reading will be minimized 9 4 0 4 Check the input waveform to the DSTS 4A using an oscilloscope Look for stray high voltage spikes or DC voltage offsets exceeding 20 VDC NOTE Always turn the DUT off when ch
3. ADC The measurement is made about one millisecond after the end of the transmitted pulse The indicated voltage will be the highest peak to peak value contained in the input pulse from the DUT 7 0 3 WIDTH MEASUREMENT A counter is activated when the first positive cycle of the pulse is encountered and is stopped on the last negative cycle The microprocessor reads the counter value and displays the width in microseconds The accuracy of the width reading is one uSec plus or minus the width of one cycle of the input waveform 7 0 4 REPLY ECHO GENERATION A time delay corresponding to the selected bottom depth is loaded into a hardware counter This counter acts as a digital one shot and is triggered by the first cycle of the input pulse from the DUT When the counter times out a reply echo is generated If another input pulse arrives before the depth counter has timed out the depth is reloaded and no echo is generated DSTS 4A OPERATO RS MAN UAL Hardware revision 3 1 3 7 0 5 REPLY FREQUENCY GENERATION A PLL circuit generates the reply frequency Normally this frequency is the same as the input frequency from the DUT 7 0 6 REPLY ECHO WIDTH GENERATION A hardware counter controls the echo duration The counter is loaded with a width value that is approximately 1 3 times the width of the input pulse from the DUT The increased width is necessary to simulate a realistic bottom echo The bottom echo is wider than the transmitted pulse becaus
4. HIGH DSTS 4A over voltage warning under warranty The input voltage should never exceed 2500 V p p Setting the load selection switch to LOW may reduce the voltage atthe input because of the lower resistance presented to the DUT 6 2 CYCLE ERROR WARNING MESSAGE The message cyc err is displayed atthe upper right of the display when the pulse contains less than four cycles The width reading will be correct but the frequency reading is not and XXX X will flash in its place Because of this the DSTS 4A will immediately switch to the manual frequency mode The message TRACK above the FREQ switch will be replaced by the frequency readings shown on the top line of the display if they were present before this error The DSTS 4A must be operated in the manual frequency mode when insufficient cycles are present in the input pulse 6 2 1 LOW CYCLE WARNING MESSAGE The message low cyc will flash at the upper right of the display if six or less cycles are present and indicates that the DSTS 4A is approaching the lower limits of its operational range The DSTS 4A requires four more cycles to be present in the input pulse for normal operation If possible increase the number of cycles in the input pulse by adjusting the pulse length of the DUT 6 2 2 BAD INPUT WARNING The message Bad In will overlay the frequency display if the input pulse contains less than two cycles is too narrow contains a large DC component or is otherwise
5. R104 2 3K D107 D108 DaO Te LOADGND Ji 5 cis p143 gt R137 47UF 56 1 7 Se FROM ATTENUATOR SWITCH A ANAGND _ _ TRIGGER OUT gz R17 TRIG BNC CONNECTOR D115 LD2 LD3 BP LOADHI INPUT Riss R134 1 ve E EXT LOAD Ee aT BP2 SS RETURN l G g 3 4700PF 3KV 1000PF 3KV 470PF 3KV 560 BW 2 2K d FRONT PANEL PARTIAL SCHEMATIC 4 6 1 LOAD SELECTION SWITCH LOW The low impedance position selects the lowest impedance internal load This load is 330 Q in parallel with 4700 pF Itis normally used with larger video and recording depth sounders 4 6 2 LOAD SELECTION SWITCH MED The medium impedance position selects the average or medium impedance internal load This load is 560Q in parallel with 1000 pF Itis used with most medium size depth sounders such as digital types with depth ranges up to 1000 feet 4 6 3 LOAD SELECTION SWITCH HIGH The high impedance position selects the highest internal load impedance This load is 2200Q in parallel with 470 pF Itis used with small flashers and shallow water graphical depth sounders 4 6 4 LOAD SELECTION SWITCH EXT LOAD The external load position selects the external load impedance connector jacks Any external load can be constructed and connected across the red and blue banana jacks on the front panel CAUTION the red jack is the high voltage side of the load Th
6. desired on and off times DSTS 4A OPERATORS MAN UAL Hardware revision 3 9 5 4 1 EXITING THE AUTO FISH MODE To exit the Auto Fish mode lift the mode switch once to return to the Auto Fish menu Lift it once more to return to the top menu Fish and bottom depth and width are preserved along with the fish echo on off times until the power is turned off 5 5 ENTERING THE AUTO PULSE MODE When the DSTS 4A is first turned on the display will display the start up message The only way to enter the Auto Pulse mode is WAITING FOR A PULSE when this screen is displayed This screen is EDI DSTS 4A V4 XX only present until the DSTS 4A receives an input pulse Therefore the DUT should have its transmitter disabled or the power turned off to enter the Auto Pulse Mode While this screen is displayed depress and hold both the FREQ and MODE switches momentarily The Auto Pulse Mode screen will appear and the DSTS 4A will output a train of pulses at the selected frequency If the WIDTH Switch is lifted momentarily the FACTORY TEST MODE screen will appear The output will now be a continuous wave of the selected frequency This is normally used to check the output level calibration The output no load is nominally a 111 mV p p square wave with the reply level set to 50 mV and the LOAD switch to low DSTS 4A Start up display message 5 5 1 PRODUCING A CONTINUOUS WAVE OUTPUT While the start up screen is displayed depress and hold both the FREQ and MO
7. revision 3 7 5 1 MENU DIAGRAM DSTS 4A REVISION 4 XX SOFTWARE A diagram of the new menu structure is included to help the user quickly select the various operating modes NOTE The DSTS 4A must be receiving an Top Menu screen Power up default input pulse from a depth sounder for these BEES 204 8 00156 0080 1250 Set frequency width depth TRACK TRACK 20 0 Menu Mode down selects next menu l l i Calibration menu screen i 4800 Ft S Feet RST Select feet meter or fathoms FT MIR FATH 4 FISH Mode down selects next menu i i l Fish menu screen Fish Echo Mode RST Select manual or auto fish echo MAN o AUTO 204 8 156 080 560 Mode up to reset go to Top Menu TRACK TRACK 27 1 FISH Manual fish echo menu Screen Mode down selects fish bottom modes Select fish width depth i Mode up to reset go to Too Menu 204 8 156 080 560 TRACK TRACK 35 1 BOT Bottom echo menu screen when in FISH mode Set freq width depth Auto Fish menu screen 4 On Off fish RST 10 25 echo START Select fish echo on off time aa Mode down to start Auto Fish echos 204 8 00156 0080 0560 Mode up returns to Auto Fish menu TRACK TRACK 27 1 FISH Auto Fish echo menu screen t Mode down selects fish bottom modes Select auto fish freq width depth Mode up returns to Auto Fish menu 204 8 156 080 560 TRACK TRACK 35 1 _BOT Bottom echo screen in Auto Fis
8. 0 3 1 RS 232 OPERATION For details on the operation of the DSTS 4A using the RS 232 port please refer to the manual addendum that was shipped with your unit or software upgrade The baud rate is preset at 9600 8 bits and no parity Typing a lower case x will enter the remote DSTS 4A OPERATO RS MAN UAL Hardware revision 3 19 mode Typing a while in the remote mode will display an abbreviated menu on the terminal RS 232 CABLE WIRING The RS 232 package includes a 6 conductor cable with R J 6 telephone modular connectors on each end A DB 9 adapter is furnished to connect this cable to the serial port of your computer or terminal See figure 4 for wiring details if the cable is damaged or lost TXOUT FROM MICROPROCESSOR x RJ 6 CONNECTOR FOR RS 232 OUTPUT N FS a J7 PART OF DSTS 4A MAIN BOARD BACK PANEL OF DSTS 4A RS 232 CABLE WIRING J7 PIN RJ6 DB 9 ADAPTER PIN COLOR NOTE 1 1 NOT USED A YELLOW 2 GREEN PINO PING NOT USED 5 BLACK REAR VIEW OF DB 9 NOT USED FEMALE CONNECTOR PART OF RJ6 DB 9 NOTE1 COLORS APPLY TO DIGIKEY P N 046 0003 ND ONLY ADAPTER UNIT DIGIKEY P N 046 0003 ND Figure 4 RS 232 connector wiring 10 3 2 GETTING OUTPUT ON A PC Any terminal program such as Microsoft Windows Terminal that supports 9600 baud with 8 bits no parity and one st
9. A current with emerging depth sounder technology As software updates are issued addendums will be sent along with the EPROM These should be inserted following this page to keep this manual up to date You may also check our web site www dsts com for latest information on our products updates and accessories DSTS 4A OPERATORS MAN UAL Hardware revision 3 21
10. DE switches momentarily The Auto Pulse Mode screen will appear and the DSTS 4A will output a train of pulses at the selected frequency If the WIDTH switch is lifted momentarily the FACTORY TEST MODE screen will appear The output will now be a continuous wave of the selected frequency This is normally used to check the output level calibration with an oscilloscope NOTE If you observe the output using a wide band digital scope the signal may appear noisy This is due to the sampling nature of digital oscilloscopes Use the scopes waveform averaging function or a band limit filter to reduce the noise 5 5 2 EXITING THE AUTOPULSE OR CW MODE Momentarily lift the mode switch and the DSTS 4A will return to normal operation 6 WARNINGS ERROR MESSAGES AND STATUS INDICATORS If the DSTS 4A does not have the proper pulse input waveform it could result in erroneous information being displayed on the screen The software will detect these conditions and display an error message on the top line of the display The process of acquiring and displaying the frequency of the DUT involves several steps The current Status is displayed to the right of the input frequency readout DSTS 4A OPERATO RS MAN UAL Hardware revision 3 10 6 1 PULSE OVER VOLTAGE WARNING If this message appears on the display immediately turn off the power to the DUT Failure to do this could result in damage to the DSTS 4A and may not be covered kkk DANGER kkk PULSE VOLTAGE TOO
11. L D 2 2 ON KHZ uSEG mSEC V P P 1 5 iN 04 6 00352 00152 1280 ee O a ouT 204 8 00352 20 0 Menu i POWER 02 20 REPLY 01 50 FREG DEPTH MODE REPLY LEVEL mV al DSTS 4A DOWN AMPL Hi Ft ERT O ZAC E Gr CHE r MED TRIG HIGH IN OUT LLow CAL 1X as Fig 2 4 1 POWER SWITCH The power switch turns the DSTS 4A on resets the microprocessor and restores all default modes and settings For a normal reset where the depth and other manual settings are retained lift the mode switch The power switch has no effect on the charge rate of the optional internal battery pack 4 2 REPLY GROUP SWITCHES Moving the FREQ or WIDTH switch will place the DSTS 4A in the manual mode for that function This is indicated by replacing the word TRACK with the selected frequency or width When the DSTS 4A is in the TRACK mode the frequency and width track the input pulse parameters This is the most commonly used mode Some microprocessor controlled depth sounders will have randomly varying pulse widths When testing these units the width must be in the TRACK mode so the echo width generated by the DSTS 4A will match the depth sounder s pulse width 4 2 1 FREQUENCY SWITCH The FREQ switch varies the reply frequency in 1 KHz steps Liftit to increase the frequency depress it to lower the frequency The rate of frequency change will increase the longer the switch is held in position The DSTS 4A operates in the manual freque
12. November 1996 Manual P N 700 011 080599 DSTS 4A 3 OPERATORS MANUAL Software V4 XX AL L AAUALAAAAAABAS RAR mm SS e e e D FREQ WIDTH PERIOD MPL KHZ uSEC msec V P ouT REPLY o1 mp FREQ WIDTH DEPTH MODE REPLY LEVEL mV z G AMPL VERNIER DOWN 2x ytd d ee a em HIGH O A EN MED HIGH LOW IN OUT LOW INTRODUCTION INITIAL INSPECTION GETTING STARTED CONTROL FUNCTIONS MENU STRUCTURE ERROR MESSAGES THEORY OF OPERATION SPECIFICATIONS IN CASE OF DIFFICULTY 10 0 OPTIONAL ACCESSORIES 11 0 WARRANTY 12 0 ADDENDUMS 2 Ot OV E oo0oo0oo0oo0o0000 Electronic Devices Inc 3140 Bunch Walnuts Rd Chesapeake VA 23322 Phone 1 757 421 2968 Fax 1 757 421 0518 DS40PT4MA3 1 INTRODUCTION The DSTS 4A is a precision instrument designed for evaluation and repair of all types of depth sounders It is capable of measuring the incoming pulse parameters and generating a reply echo pulse over a very wide range of frequencies For further information refer to the specifications The micro processor in the DSTS 4A controls all functions with the exception of the reply level The incoming pulse is analyzed and displayed on the top line of the display Outgoing parameters are displayed on the bottom line Applying power to the DSTS 4A resets the processor and displays WAITING FOR A PULSE This message will remain on screen until the first pulse is received Within three pulses the DSTS 4A begins to display a
13. OF OPERATION The DSTS 4A has a series of hardware counters that measure the incoming pulse characteristics Based on the information contained in these counters a microprocessor calculates the pulse parameters and displays them on the LCD screen The first two and last two cycles of the input pulse are discarded as they adversely il affect the accuracy of the frequency Wd ul il measurement Notice the lower frequency cycles oy ul Weess at the beginning and end of the waveform ECKE illustration to the right Tracking gate and input pulse 7 0 1 MEASUREMENT GATE A measurement gate is generated that tracks the center area of the input pulse The length of this gate is counted and the pulse frequency is calculated If the pulse width varies on a pulse to pulse basis the gate will try to adjust to the greatest possible width without extending beyond the limit of two cycles from the beginning and end of the pulse Because the gate cannot predict what the width of the next input pulse might be it tends to lock on to the narrowest pulse in the input stream If the next pulse is longer the gate will increase This continues until a pulse that is shorter than the gate limits arrives The gate then narrows and repeats the process When the DSTS 4A is reset by the MODE switch the gate is immediately forced to the maximum width for best frequency accuracy 7 0 2 VOLTAGE MEASUREMENT Voltage measurement is through a peak to peak detector and a
14. S 4A has fewer cycles in the center of the pulse with accurate zero crossings to calculate the frequency with Therefore contamination of the first two or more cycles has a greater effect on the frequency reading of short pulses Accurate readings are obtained by using the longest possible pulse Always reset the DSTS 4A after the input pulse has been increased The reset is necessary to force the DSTS 4A to search the pulse pattern for the longest usable gate width thus yielding the greatest accuracy 9 6 OPENING THE DSTS 4A Any time you open the DSTS 4A you should be working on a static mat The integrated circuits used in the DSTS 4A are very sensitive to static discharge Please exercise all due caution Unplug the power cord from the DSTS 4A and remove the four rubber stick on feet by peeling them off with your fingers Remove the four screws recessed in the plastic feet and remove the feet and plastic bail Set the DSTS 4A upright and carefully lift off the top half of the case including the black band Make sure that the back panel DOES NOT lift up as you do this If the back panel lifts the voltage regulator may be torn from the main board The front panel should also stay with the bottom part of the case 9 6 1 REPLACING THE EPROM Remove U21 the EPROM that is located on the main board near the left front corner Replace this with the new EPROM Make sure that pin one is towards the notch in the socket and that the all the pins are pro
15. These components are located on the front panel just left and above the TRIG BNC connector To gain access to these parts the front panel must be disassembled a procedure beyond the scope of this manual DSTS 4A OPERATO RS MAN UAL Hardware revision 3 14 SPECIFICATIONS Parameter Range Resolution Accuracy input frequency 2 9 to 650 KHz 1 KHz 02 100 Hz input width 207 to 20 000 uS EH 02 2 cycles input period 10 to 9999 mS 1 mS 02 1 mS input amplitude 50 to 2500 Vp p 10 Vp p 5 10 Vp p Min input level 30 Vp p N A 10 Vp p Output frequency 2 9 to 650 KHz 1 KHz 05 Output width 10 to 20 000 uS 100 uSec 02 Output depth 1 to 999 9 ft mt 1 unit 02 Output level 10 to 350 000 uV 1 2 5 steps 1 5 dB Power requirements 10 15 VAC or 12 18 VDC 120 mA nominal Size and Weight 10 W by 7 D by 4 5 H Shipping Wt 6 Lbs 9 IN CASE OF DIFFICULTY This section discusses possible problems their solutions and how to open the DSTS 4A for service or curiosity 9 1 FREQUENCY READOUT CHANGES VERY SLOWLY WHEN TUNING DUT If the input pulse of the depth sounder under test is in the 20 to 40 uSec range the time constant of the frequency filter will be very long If the frequency of the depth sounder is changed you must wait for the frequency display to catch up with the new input frequency Because of this time lag it is recommended that frequency tuning be done with pulses over 100 uSec long If this is not possible tune the
16. anging the load impedance 9 4 1 FREQUENCY CHANGES WITH LOAD IMPEDANCE If the frequency changes several percent with a change in load the DUT s oscillator is experiencing load pulling This is usually not critical and often occurs with inexpensive sounders However if the same DUT is checked with two different DSTS 4A s the frequency readings may vary slightly This is due to the tolerance 20 of DSTS 4A OPERATO RS MAN UAL Hardware revision 3 16 the capacitive portion of the internal loads of the DSTS 4A This is not an error in the DSTS 4A but merely reflects the fact that the DUT oscillator is sensitive to external load variations 9 5 HOW TO GET THE MOST ACCURATE FREQUENCY READING The accuracy of the frequency readings depends on several factors The single most important one is the width of the pulse When a pulse burst is generated and sent through a bandpass filter the period between the zero crossing points of the first and last few cycles is different than the period between the zero crossing points in the center of the pulse Additionally this problem is aggravated if the pulse has some chirp or frequency change with time Chirp is usually encountered with keyed oscillators found in inexpensive depth sounders and can cause a Significant frequency change in the first portion of the pulse For this reason the DSTS 4A discards the first and last few cycles of the pulse from the DUT As the pulse width gets narrow the DST
17. d both the FREQ and MODE switches momentarily The message should change to Up Dn Auto Pulse Mode The DSTS 4A will now put out a train of pulses at a frequency of 100 KHz The frequency may be varied from 10 to 650 KHz using the FREQ switch To restore the DSTS 4A to normal operation momentarily raise the MODE switch This completes the initial inspection and test of the DSTS 3 GETTING STARTED Reset the DSTS 4A by lifting the MODE switch momentarily Set the LOAD SELECTION switch to LOW Setthe REPLY LEVEL switch to 50 mV DSTS 4A OPERATORS MAN UAL Hardware revision 3 2 Connect a depth sounder to the IN OUT BNC connector Refer to figure 1 showing the optional BAL 550 to connect depth sounders with two wires and a shield Apply power to the depth sounder The PULSE LED will flash each time the depth sounder transmits and the message WAITING FOR A PULSE will disappear After receiving CAUTION never set the LOAD SELECTION switch to EXT LOAD without an external load plugged in Some depth sounders can be damaged if operated into an open circuit DSTS 4A DEPTH MODE EXT LOAD HIGH f P Le i IN OUT LOW BNC CABLE I FROM DUT E the third pulse the top line will display the incoming frequency width period and peak to peak voltage The frequency and voltage are averaged and will stabilize after ten or more pulses have been received The depth defaults to twenty feet when pow
18. depth sounder a small amount and wait for the reading to stabilize before making an additional adjustment Always reset the DSTS 4A and wait for the filter to settle for maximum accuracy 9 2 2 APPEARS IN FREQUENCY READOUT The depth sounder under test has too narrow a pulse output Try setting the depth sounder to a deeper range Most depth sounders will increase their pulse width on the deeper ranges Reset the DSTS 4A to let it acquire the longer pulse 1 Specified for input pulse widths greater than 99 microseconds Input pulse must contain at least 6 cycles 3 At 50 KHz Approximately 200 Vp p at 500 KHz DSTS 4A OPERATORS MANUAL Hardware revision 3 1 5 9 3 DEPTH SOUNDER UNDER TEST WILL NOT ACQUIRE REPLY ECHO If the DUT will not pick up the reply echo from the DSTS 4A and you are sure that the DUT is a properly working unit check the depth setting and the width mode The depth must be set to a value less than the maximum depth range of the DUT The width and frequency should be in the TRACK mode Momentarily lift and release both the FREQ and WIDTH switches to restore the TRACK mode Turning the DSTS 4A power switch off then back on will restore the default modes and depth settings 9 3 1 IS THE DEPTH SETTING WITHIN RANGE The first thing to check is the depth setting Make sure the DSTS 4A is set to a reply depth that is less than the range of the DUT If the DUT is on the 15 foot range and the DSTS 4A replies at
19. e full DSTS 4A OPERATO RS MAN UAL Hardware revision 3 6 pulse voltage appears at this jack The blue jack is the low voltage return side of the load and is nota ground Do not ground the blue jack to the chassis or the reply pulse will be shorted to ground and no reply echo will be seen If no load is plugged into the jacks the impedance at the IN OUT BNC connector will be in excess of 50KQ This high impedance is nearly an open circuit and may damage high power depth sounders External loads are easily constructed using a double banana jack plug box similar to ITT POMONA type 2098 Custom load boxes can be made to the depth sounder manufacturer s exact specifications and plugged in as needed 4 7 IN OUT BNC CONNECTOR The DUT connects to this jack For depth sounders with unbalanced one wire and a shield outputs the connection is made directly to the DSTS For depth sounders with balanced two wires and a shield outputs use of a balanced to unbalanced load transformer such as the EDI model BAL 550 shown in figure 1 is highly recommended 4 8 TRIG BNC CONNECTOR This connector provides a positive trigger output that precedes the reply pulse by 10 microseconds Itis used to trigger an oscilloscope so the reply pulse is easily tracked through the receiver sections of the DUT DO NOT CONNECT a depth sounder to this connector Doing so will harm the DSTS 4A Usually the diode D110 is destroyed Reference figure 3 for further information
20. e some energy returns over a longer path due to the beam width of the transducer 7 1 INTERNAL LOAD IMPEDANCES Refer to figure 3 The DUT connects to the internal load through the front panel IN OUT connector The low side of the load connects to the junction of D107 D108 and R137 This signal is referred to as LOADGND in figure 3 The reply signal from the attenuator buffer is applied to LOADGND through R143 and returns through the internal load to the IN OUT connector 7 1 1 EXTERNAL LOAD J ACKS Refer to figure 3 When the LOAD switch is in the EXT LOAD position the external load jacks are selected in place of the internal loads The red jack goes to J 104 the input of the DSTS 4A The blue jack goes to the LOADGND in the DSTS 4A The external load goes between these two jacks The reply signal on LOADGND is developed across R137 a 30 ohm resistor The mechanical spacing of the banana jacks is three quarters of aninch This accepts standard dual prong connectors 7 2 REPLY TRIGGER BNC CONNECTOR The reply trigger is a narrow 10 uSec positive pulse that precedes start of the reply echo pulse by about 10 uSec This trigger pulse is output to the BNC TRIG connector It is normally used to trigger an oscilloscope when observing the return pulse in the receiver stages of a depth sounder WARNING If a high voltage pulse is applied to the TRIG connector D110 and possibly R147 will be destroyed Please be careful not to do this
21. er is applied The time that it takes for the readings to stabilize is based on the pulse 191 9 00911 0198 1220 repetition rate and pulse width of the DUT TRACK TRACK 020 0 Menu Depth sounders that have high pulse repetition rates will produce a nearly DSTS 4A display with pulse input instantaneous reading while deep water sounders with pulse rates of one or less per second will take longer Depress the MODE switch to select the calibration menu From there choose feet meters or fathoms Lifting the MODE switch will return you to the main display Measure the receiver sensitivity by reducing the REPLY LEVEL to the point where the echo just disappears This completes the most basic mode of testing SHIELD FIG 1 4 CONTROL FUNCTIONS Refer to figure 2 for control identification The four switches below the display control the advanced operating features of the DSTS 4A The first three grouped under the DSTS 4A OPERATORS MAN UAL Hardware revision 3 3 heading REPLY control the output frequency width and the reply depth The fourth or MODE switch is a multi purpose switch Lifting it returns the DSTS 4A to the normal operating mode Depressing it selects different menus such as the CAL menu for setting the calibration units i e feet meters or fathoms PULSE RB 1 FREQ WIDT PERIOD AMP
22. h mode Select bottom freq width depth DSTS 4A OPERATORS MAN UAL Hardware revision 3 8 5 2 SELECTING UNITS OF CALIBRATION feet fathoms meters From the top menu push and hold the MODE switch While the MODE switch is held down a brief explanation of the upcoming menu is given When the operator releases the switch the actual menu appears To select meters briefly press down the switch under MTRS The symbol for meters will be displayed in the lower right area of the screen To return to the top menu just lift the mode switch The DSTS 4A is now in the metric mode This is indicated by the symbol appearing just to the right of the depth readout 5 3 ENTERING THE MANUAL FISH MODE From the top menu depress the mode switch to enter the CAL menu screen and then release it Depress the mode switch again and the fish menu screen will appear Note the screen displays the new switch functions The FREQ switch is now labeled as MAN to indicate that depressing it will enter the manual fish echo mode Depress the MAN switch once to start the fish echo The FISH above the MODE switch indicates that the DSTS 4A is in the fish echo mode and is replying with two echoes Set the fish echo width and depth from this menu screen Cycling between the bottom single echo and fish dual echo mode is done by momentarily pressing the MODE switch down When the DSTS 4A is in the bottom mode as indicated by BOTM above the MODE switch the bot
23. is prevents accidental damage to the DSTS 4A 10 2 2 GETTING STARTED WITH THE BATTERY PACK INSTALLATION Open the DSTS 4A as described in section 9 Place battery pack inside rear section of upper lid over the vented area Batteries should be in contact with top of case Secure with supplied 6 32 x 3 8 screws Do not over tighten screws in an effort to pull board down flush with the studs Just snug the screws down so the batteries are held firmly against the top of the case Leave some space between the board and the plastic studs so the board does not warp 10 2 3 WIRING THE BATTERY TO THE DSTS 4A The next step is to solder the battery pack leads to J4 located at the back of the main circuit board adjacent to the power connector J6 This can be done without removing the board by soldering the leads from the top side Be careful not to push too much wire through the pads as they may contact each other under the board causing a short Connect the positive lead red or orange from the battery pack to J4 pin two Pin two is the pad that is closest to the power jack and has the thinner of the two traces connected to it Connect the negative lead black or brown of the battery pack to J4 pin one Pin one is farthest from the power connector and has the wider trace connected to it DSTS 4A OPERATO RS MAN UAL Hardware revision 3 18 10 2 4 CHECKING THE INSTALLATION Check the connections to make sure the polarity is correct Install the supplied f
24. kes to settle to the correct reading is variable indicators of the filter s state are displayed in the space to the right of the 100 Hz input frequency digit 6 3 1 FREQUENCY FILTER SETTLING TIME INDICATORS x Raw data is displayed Filter is initializing and data may not be accurate Filter is adapting to pulse width and frequency display becomes more accurate Pulse width has decreased and filter time constant is readjusting Filter has settled Frequency accuracy is within 100 Hz Filter has settled but input pulse width is variable Accuracy is within 100 Hz 6 3 2 TYPICAL ACCURACIES FOR NARROW PULSES This table is a guide to the minimum practical combinations of frequency and pulse width required by the DSTS 4A with REV 4 XX software It is nota specification for the accuracy of the DSTS 4A In each case the pulse width was reduced enough to blink the decimal point or display the low cyc error Note that the lower frequencies must use a longer input width The DSTS 4A requires at least six input cycles to work Therefore as the frequency drops increasing pulse widths are required In these cases 3 5 and 12 5 KHz the width was reduced until the low cyc warning appeared Input frequency KHz Input width uS Measured frequency KHz 3 5 2000 3 5 12 5 560 12 5 30 233 30 0 50 130 50 0 100 65 100 0 150 43 149 9 200 35 199 9 300 27 299 8 455 25 454 8 DSTS 4A OPERATO RS MAN UAL Hardware revision 3 12 7 THEORY
25. ncy reply mode after the FREQ switch is moved To restore the TRACK frequency mode of operation momentarily lift then release both the FREQ and WIDTH switches If the FREQ switch is released before the WIDTH switch is released then only the frequency auto track mode is restored This is useful if the value of a preset width is to be preserved DSTS 4A OPERATO RS MAN UAL Hardware revision 3 4 4 2 2 WIDTH SWITCH The WIDTH switch varies the reply width in 1 uSec steps Lift it to increase the reply width depress it to lower the width The rate that the width changes will increase the longer the switch is held in position The DSTS 4A operates in the manual width reply mode after the WIDTH switch is moved To restore the TRACK width mode of operation lift then release both the FREQ and WIDTH switches at the same time If the WIDTH switch is released before the WIDTH switch is released then only the width auto track mode is restored Some depth sounders deliberately vary pulse widths during operation to reject noise When testing these units the WIDTH must be in the TRACK mode so the DSTS 4A s reply echo will follow the input pulse variations If this is not done the DUT may not respond 4 2 3 DEPTH SWITCH The DEPTH switch varies the reply echo depth in tenth unit steps Lift it to decrease the depth depress itto increase the depth The rate of depth change will increase the longer the switch is held in position 4 3 MODE SWITCH Refe
26. nd average the input information The output frequency depth and pulse width are automatically set To check the depth sounder under test DUT read the top line of the display to confirm the pulse parameters and adjust the reply level to measure the receiver sensitivity Depth calibration can be done in feet fathoms or meters The velocity of propagation is 4800 feet second in the foot and fathom range and 1500 meters second on the metric range 2 INITIAL INSPECTION Unpack the DSTS 4A The shipping box will contain a wall plug power supply manual and any accessories you have ordered Check the contents against the packing list and also check for mechanical damage Please report any discrepancies to EDI as soon as possible Save the shipping box should you need to return the unit 2 1 PRELIMINARY ELECTRICAL TEST Note Do NOT connect a depth sounder to the DSTS 4A for this test The DSTS 4A comes with a wall plug transformer This transformer is rated for 110 120 VAC 50 60 Hz current If you have SCH e use a Se VAC Se or Waiting for a pulse order the optional 220 VAC transformer unit Plug the transformer into the mains and EDI DSTS 4A 3 V4 XX connect the end of the cord to the power DSTS 4A Start up display message connector on the back panel of the DSTS Turn the power switch on The startup message shown will appear on the liquid crystal display LCD This indicates the processor has passed the internal diagnostics Depress and hol
27. not usable Checking the input pulse with a scope while the DSTS 4A is connected will usually reveal the problem 6 2 3 NARROW PULSE WARNINGS If the input pulse is not wide enough for last digit accuracy the decimal point in the frequency readout will begin to flash This indicates the accuracy has degraded to 05 of the indicated reading If the pulse is extremely short the frequency display will show flashing question marks Decimal point flashes Accuracy within 300 Hz at 600 KHz or 05 flashes Accuracy is worse than 1 Use a longer pulse DSTS 4A OPERATORS MAN UAL Hardware revision 3 11 6 3 FREQUENCY ACCURACY AND INPUT PULSE WIDTH The DSTS 4A will work with pulses of 4 or more cycles and widths below 20 uSec For example this makes the DSTS usable with a 35 uSec input pulse at 200 KHZ To obtain good frequency accuracy with a 35 uSec pulse it is necessary to average many readings of the raw frequency data with a filter For a very narrow pulse the filter may average several hundred input pulses before settling at the correct value This will take a lot of time if the input pulse repetition rate is slow If the input pulse is wider it contains more frequency information and the filter needs fewer pulses Fewer pulses take less time and an accurate reading is displayed much faster To compute an accurate frequency as rapidly as possible the filter adapts to the width of the input pulse automatically Since the time it ta
28. op bit will work just fine Connect the cable as shown in figure 4 Consult the manual addendum that was shipped with your unit or software upgrade package for details on command structure and data format DSTS 4A OPERATORS MAN UAL Hardware revision 3 20 10 3 3 RS 232 OPTION PACKING LIST QUANTITY DESCRIPTION PART NUMBER 1 6 Ft RJ 6 jumper cable EDI p n RJ 6 600 1 RJ 6 to DB 9 adapter Digi Key p n 046 0003 ND 1 Manual addendum N A 1 upgrade kits MAX 233 chip EDI p n 100 064 1 upgrade kits 27C256 EPROM EDI p n 100 070 Upgrade EPROM Please note that the MAX 233 chip and EPROM are shipped installed in the DSTS 4A when the RS 232 option is factory ordered For user installed upgrades these parts are included with the cable items in the above packing list 10 4 DSTS 4A SERVICE MANUAL FOR HARDWARE REVISION 3 The service manual covers the calibration and theory of the DSTS 4A Full schematics and parts lists are included 11 WARRANTY INFORMATION Unit will be repaired free of charge for one year from date of purchase providing there is no water damage or other evidence of improper use or handling Purchaser must ship unit prepaid to address below EDI will pay the return freight For repair ship to Electronic Devices Inc 3140 Bunch Walnuts Road Chesapeake VA 23322 ATTN Service Department Please enclose a note describing the problem 12 ADDENDUMS New features and capabilities are constantly pursued to keep the DSTS 4
29. perly inserted into the socket 9 6 2 CLOSING THE DSTS 4A Dress the ribbon cables away from the front panel This is very important because some of the front panel PCB traces carry the full input pulse voltage This voltage may be up to 2 500 volts If an arc occurs from the PCB to the ribbon cable the main PCB will be severely damaged Place the cover on with the ventilation slots near the back DSTS 4A OPERATO RS MAN UAL Hardware revision 3 17 panel Slide itin place and replace the plastic feet tilt bail screws and rubber feet Do not over tighten the case screws Replace the rubber feet 10 OPTIONAL ACCESSORIES This section lists options available for the DSTS 4A 10 1 BAL 550 MATCHING BALUN The BAL 550 is a balanced to unbalanced line transformer It should be used when connecting a depth sounder having two wires and a shield to the DSTS Binding posts for the shield and two signal conductors make connections easier External noise rejection is improved and receiver sensitivity measurements at low levels are more accurate 10 2 BP 4A INTERNAL RECHARGEABLE BATTERY PACK A rechargeable internal battery gives over 4 hours of continuous field operation from the DSTS 4A Recharging is automatic and occurs whenever the DSTS 4A is connected to a source of external power 10 2 1 BP 4A BATTERY PACK INSTALLATION WARNING Before proceeding make sure fuse is not installed on the battery pack circuit board before proceeding any further Th
30. r to the menu diagram in section 5 for further information Lifting the MODE switch will display Resetting on the top line of the display and moves the menu up one level Frequency width and depth settings remain as previously set and the DSTS 4A frequency measuring gate will adjust for the best accuracy Depressing the MODE switch will cycle down through the various menus Refer to the MENU STRUCTURE in Section 5 for further information on the mode and reply group Switches 4 4 REPLY LEVEL mV The reply level switch varies the reply level from 10 microvolt 01mV to 50 millivolts RMS The AMPL VERNIER must be rotated to the maximum counter clockwise position CAL 1X to obtain the output voltage selected 4 5 AMPLVERNIER The amplitude vernier multiplies the setting on the REPLY LEVEL switch If the reply level is setto 2 mV and the AMPL VERNIER is set to 1 5 the actual reply level is 3 millivolts 4 6 LOAD SELECTION SWITCH The load selection switch selects from one of three internal load impedances or the external load jacks on the front panel Refer to the partial schematic in figure 3 DSTS 4A OPERATORS MAN UAL Hardware revision 3 5 U101A Lo Lupi D104 INPUT 3 B a Ni 7 e ez gt gt a l 33K EECH PAD R101 Kee 4049 4049 cos l Ria 4049 J104 Ko e Ze A 6 8v PULSE uF TI we R102 D 33K BNC I O CONNECTOR J108 PAD R103 33K 101 TO DIGITAL VOLTMETER 20
31. tom depth and width can be set The bottom reply echo width tracks the pulse from the DUT unless the width has been manually set Note The fish echo does not proportionally track the incoming pulse width as the bottom echo does 5 3 1 EXITING THE MANUAL FISH MODE To exit the fish menu lift the mode switch briefly and the top menu will appear The previously entered values for fish depth and width are retained in memory until the power is turned off 5 4 ENTERING THE AUTO FISH MENU OPTION From the top menu momentarily press the mode switch down The CAL menu screen will appear Momentarily depress the MODE switch again to enter the Auto Fish menu The number of consecutive fish echoes returned is set using the FREQ switch This can range from one to ninety nine echoes The off time for the fish echoes is set with the WIDTH switch This can range from one to two hundred and fifty bottom echoes The default values are for ten fish and bottom echoes followed by twenty bottom only echoes To start the Auto Fish generation press the mode switch down The Auto Fish menu will appear The symbol justto the left of the word FISH indicates that the unit is in the Auto Fish mode Cycling between the bottom single echo and auto fish dual echo mode is done by momentarily pressing the MODE switch down To change the number of fish echoes lift the mode switch once to go to the Auto Fish menu screen Use the frequency and width switches to select the
32. use plug the power supply in and allow the DSTS 4A to charge for 15 minutes Remove the power supply and check the DSTS 4A to see if it will run from the battery pack for a few moments If all is OK replace the cover plastic and rubber feet 10 2 5 CHARGING THE BATTERY The battery pack is not charged before shipment and a 24 hour charge is recommended before field use Operating time will be four to six hours after a full charge The battery will charge at about the same rate whether the DSTS 4A is turned on or left off Please use the wall plug transformer 12 VAC 500mA supplied with the DSTS 4A to prevent over or under charging of the battery pack 10 2 6 RECHARGEABLE BATTERY PACK OPTION PACKING LIST QUANTITY DESCRIPTION PART NUMBER 1 Rechargable battery pack BP 4A 1 3AG 4 A fuse N A 1 Installation instructions Please read these updates 10 3 RS 232 OPTION The bi directional RS 232 option allows remote setting of all parameters except amplitude The bi directional interface is useful for automated engineering or production testing 10 3 0 1 CHECKING FOR THE RS 232 OPTION INSTALLATION If the RS 232 option is installed in the DSTS 4A the startup message will appear on the liquid crystal display LCD as shown WAITING FOR A PULSE EDI DSTS 4A_ VX XX S The S at the end of the software version indicates that the unit has the RS 232 output hardware and software installed Pulse and depth parameters may be set and read back 1
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