Manual - Quartzlock
Contents
1. cccceeceeeeeeeeeeeeeeeee eee eeeeeetteeeeeeeeeeeeeeeeeea 10 Ile le Lo eee ee eee a ne ere ee ee eee ee 11 Appendix A Board Variation Configuration cccccceeeeeeeeeeeeeeeeeeseeeeeeeeaaaaeeaneeeeeeeeees 13 TOXO Version aic eite clca ccee ica acrcnaeaceetsnsc keine mote heap eeente canteen 13 OCXO Version without 1PPS holdover and user adjustable PPG 13 OCXO Version with 1PPS holdover and user adjustable PP 13 Appendix B uP RS232 control codes sscssccscncesccatoanediecccadesetuteseningenthiesusuegudnsuccedonededeewtess 15 Appendix C NMEA 0183 Protocol cccccceeeeeeeee cette eee eeeeeeeeeeeeeeeeeeeaeeaaaeaaaeeaaeeeeeeeeees 19 uge elt 19 NMEA 0183 communication Interface 19 NMEAcO 183 message GEIER user sirina aale ere ge 19 Appendix D ISIP ProtoCol E 21 Appendix E Connector Jumper and Link References sssessesssesssssesereeesrrrrrrrrrrrnnne 22 Appendix F EEPROM defaults siscieiicciiiar kann ni anaana anapi a 25 Appendix G Board Layout E 26 Appendix H Instrument RS232 Connections 9 Way Male Connechor 28 BO Ee E8000 E801 LA E 28 E8 X E8 Y E8000 E8010 TSIP Optom iniicisnanisviniasdsapaterucrisavidarsantiadeaseabsbeoteberianeians 28 E8000 TT E8000A verine Ea e ee Monniustaess 28 Appendix Board Test assests sas cectiscans ci desc cieeetelcgeted Sotto eactivnaae nace daauegaeaea eau eiememnanees 29 WARN GI TWO case cetaceans che adai iaaa a aidaa a aed eect cated utes 29 Circuit LEE ee erte dE ee2. E8 1PPS Series A5 Manual 16 July 2014 Page 13 of 40 Quartzlock Model E8 1PPS Series Operation Manual TCXO1 TCXO2 U13 U17 U24 U28 U38 U39 U40 U41 Link configuration Link position 2 Link2 position 2 Link3 position 1 Link4 position 1 LinkS position 2 Link6 position 1 Link7 short 8V tuning E8 1PPS Series A5 Manual 16 July 2014 Page 14 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix B uP RS232 control codes RS232 control codes all values following command or returned from the microcontroller are hexadecimal unless stated backed up in EEPROM OS Overall Status OS returns overall status bytes aa bb cc dd eeee ffff aa is test status byte bits set bi SOPPS output default 1PPS bitl SOPPS input default 1PPS bit2 disable auto cal bit3 disable 1PPS output bit4 disable 1PPS input time tag bit5 disable frequency correction Kalman filter updated bit6 disable Kalman filter update bit7 disable state control bb is lock status byte bits set bt 1 2 state 0 to 7 bit3 normalise DACs cleared automatically bit4 OCXO warmed up bits loop locked bit6 Disable 1PPS quantization correction bit7 zero clock on next 1PPS capture cc is output status byte bits set bi IPPS base last input time tag bitl IPPS base Kalman phase estimate otherwise 1PPS base is zero bit2 Disable user 1PPS offset calculation enables PO command bit3 7 NU S dd is auto cal byte set to FF on loading new firmwa
3. S1 2E 14 S2 5E 12 Rmeas 225E 18 OSCcontrolconstant 0 4E 9 OSCtunespan 5 0 maxphasedriftO 5000 in nanoseconds DEFAULT 4 TCXO low performance with 0 to 3 3V tuning Trimble receiver S1 2E 11 S2 3E 10 Rmeas 2 5E 15 OSCcontrolconstant 5E 6 OSCtunespan 3 3 maxphasedriftO 200000 in nanoseconds Notes default is loaded using EDx command where x is default number After loading a default software will attempt to calibrate the actual tuning slope control constant of the oscillator Lock state must be 4 for this to occur E8 1PPS Series A5 Manual 16 July 2014 Page 25 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix G Board Layout Ext 10MHz input z Ei 5 E8 1PPS Series A5 Manual 16 July 2014 Page 26 of 40 Quartzlock Model E8 1PPS Series Operation Manual 126 24 E8 1PPS Series A5 Manual 16 July 2014 Page 27 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix H Instrument RS232 Connections 9 Way Male Connector E8 X E8 Y E8000 E8010 Pin N C RS232 RX NMEA Data RS232 TX NMEA Data N C Ground N C N C N C N C OO O ke E8 X E8 Y E8000 E8010 TSIP Option Pin N C RS232 RX TSIP RS232 TX TSIP N C Ground N C N C N C N C SO OOS OY S eeng E8000 TT E8000A Pin N C RS232 RX GPS NMEA Data RS232 TX GPS NMEA Data RS232 RX Data Trimble TSIP Ground N C RS232 RX E8 Series Micro Controller RS232 TX
4. and the Q output of U9A This is applied to the gate of TR1 which charges the integrator an amount which depends on the pulse width In the resting state the integrator U14 is stabilised by feedback through U10 A bias voltage of 2 0 volts is applied to pin 4 of U10 The integrator positive input pin 3 U14 is connected to 2 5V derived from a potential divider from the 5V reference Current flows to the negative input through R10 and then to the output of U10 through D2 and R11 The positive input of U10 is connected to the integrator output through R12 The effect is to stabilise the integrator output voltage at 2 0 volts When a 1PPS pulse arrives U9B is set This applies a higher positive voltage to U10 positive input via R15 and D3 The output of U10 goes high and reverse biases D2 effectively disconnecting the stabilisation circuit from the integrator The pulse to be expanded length 100 to 500ns turns on TR1 The integrator charges due to current in R13 to an output voltage between 3V and 8V depending upon the pulse width After TR1 turns off the integrator discharges due to current in R14 This discharge is about 2000 times slower than the charge rate which expands the input pulse to a time between 200us and Ims The positive input of the fast comparator U5 is biased at 1 9V When the integrator output voltage falls to this level the output of U5 goes high generating a second capture via OR gate U12 The processor can measure the t
5. turn the power off immediately and let the unit dry completely before turning it on again Clean with a damp with water cloth Never spray cleaner directly onto the unit or let liquid run into any part of it Never use harsh or caustic products to clean the unit E8 1PPS Series A5 Manual 16 July 2014 Page 5 of 40 Quartzlock Model E8 1PPS Series Operation Manual E8 1PPS Series GPS Timing amp Frequency Reference Introduction The GPS clock is shipped ready for operation No adjustments are needed to have a 10MHz frequency reference and 1 pulse per second time reference within 20 minutes of initial switch on The status of the GPS lock is shown on four LEDs on the front panel For more information as to satellite signal strengths etc a computer with RS232 may be connected to the interface A program such as NMEA Time may be used to display information from the GPS receiver Installation The antenna should be installed preferably with a 360 degree view of the sky However the receiver is very sensitive and will give good results with the antenna on a window ledge or even inside a building The satellite signal strengths may be checked after installation using a computer with suitable software connected to the RS232 interface The DC power supply should be connected The unit will operate with any voltage between 12 and 18V DC Current consumption for the E8 X is about 250mA max and the E8 Y E8 1PPS about 300mA continuous 600
6. 10MHz output If the OCXO calibration does start send SR software reset to stop it The special board test software is started by entering state7 The following command is used OSLO7 The reply should be BOARD TEST 0 In this state all the normal interface commands are locked out except the keys I increment and D decrement In some tests the keys H high and L low can also be used I and D may be freely used to step from one test to another The tests may be performed in any order Test F will roll over to test 0 when incremented TEST 0 1PPS output delay control THIS TEST CAN ONLY BE USED IF 1PPS HOLDOVER OPTION IS FITTED Connect oscilloscope channel to TP7 via a divide by ten probe Connect channel 2 to TP3 via a divide by 10 probe Bandwidth of oscilloscope and probes should be at least 200MHz Trigger on channel 1 Time base should be single shot sampling The rising edge on TP7 is the start marker zero time of the internal clock The delay of the 1PPS output is checked relative to this marker The 1PPS output is switched to 50PPS for this test to provide a faster update rate Using the H and L keys the delay may be stepped in 10ns increments This should be observed on the oscilloscope The interface will show the current delay signed decimal the shift register delay in 50ns steps and the delay vernier hex The delay vernier is the programming word applied to U30 Linearity check Transfer to probes
7. 29 Required FE GUID IGN EE 32 Board Set E EE 32 Stee nl E 32 Power Supplies eege ssc ease gt aac ecg zea a Nl ada eas Se nese 32 Board UNCON eg 33 Final Board Configuration sss see coessevecsce bed reavetendensicd ea vagnsvaued tends dedesssdesebeeeudeacweneonpeseeeis 36 GPS Receiver Contrat seicicticesccesecdentontiersnecaccennniendoesduivtuneniersineneteaudaveedectencs 37 Controlled Oscillator Auto Calibration cccceccccceeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeteeeeeeeeeeeeeea 37 State ON cece citer cece snes ede eyed nea ac A ged rete Scape tien acdc ces tarde teen ees ined eee 38 User Performance TSG esoe eeegegeegEg deeg 39 E8 1PPS Series A5 Manual 16 July 2014 Page 3 of 40 Quartzlock Model E8 1PPS Series Operation Manual Safety Considerations General This product and related documentation must be reviewed for familiarisation before operation If the equipment is used in a manner not specified by the manufacturer the protection provided by the instrument may be impaired Before Applying Power Verify that the product is set to match the available line voltage and the correct fuse is installed Before Cleaning Disconnect the product from operating power before cleaning WARNING Bodily injury or death may result from failure to heed a warning Do not proceed beyond a warning until the indicated conditions are fully understood and met CAUTION Damage to equipment or incorrect measurement data may resu
8. as WinOncore should be installed on the user s PC Connect the unit to the PC and start the program It may be necessary to set the port and baud rate 9600 The receiver is preset to output 3 sentences on a continuous basis These are Ha position status data Hn 12 channel TRAIM status message and Bb Visible satellites The various windows available from the program should show current satellite data etc It is important to note that some parameters shown by the program will not correctly indicate the actual state of the receiver This is because the program does not automatically update its information when started In particular the TRAIM algorithm will be shown as off when in fact it is by default on in the receiver For the receiver to operate correctly the site survey must be enabled and the TRAIM must be on If this is not the case the receiver will track satellites and compute a fix but the red lock LED will not go out showing the 1OMHz output is in the standby state If the receiver gets stuck in a state where it does not lock the user may inadvertently disabled the TRAIM or the site survey To get back to a known state the following should be performed The messages can be sent using the message window in the WinOncore software Return to factory default state CT Enable Position Auto survey consult the CW12 user manual for further details Gd03 Enable T RAIM algorithm consult the CW12 user manual fo
9. is less than the threshold state 4 is entered and the lock light is switched off If the 1PPS captures stop for more than 6 seconds state O is entered also if captures are more than MAXTIMEOFFSET 20us from initial capture when clock was reset in this state the Kalman filter is made adaptive The frequency error is high so the effective filter bandwidth is too narrow to track warm up drift of the oscillator The scaling parameter of S1 which is the random walk FM noise root variance normally preset to 1 is increased according to the value of the filtered frequency error ratio After each change to SIscale the Q matrix is recalculated STATE 4 E8 1PPS Series A5 Manual 16 July 2014 Page 38 of 40 Quartzlock Model E8 1PPS Series Operation Manual The normal running state If the filteredfreqerror rises above the high threshold loss of lock is assumed and state 5 re entered If the captures stop the holdover state 6 is entered STATES In this state the Red lock LED flashes rapidly In this state the Kalman filter is made adaptive The frequency error is high so the effective filter bandwidth is too narrow to track warm up drift of the oscillator The scaling parameter of S1 which is the random walk FM noise root variance normally preset to 1 is increased according to the value of the filtered frequency error ratio After each change to SIscale the Q matrix is recalculated If captures stop holdover state 6 is entered STATE6
10. string EWNaaaabbcccc c Writes bb bytes to starting address aaaa Character pairs cc etc are interpreted as hexadecimal numbers Dump RAM DRaaaabb returns bb bytes from starting address aaaa as hexadecimal numbers character pairs Write Flash Memory WF Not Used Read Flash Memory RF Not Used Repeat Interval RI returns command repeat interval aa E8 1PPS Series A5 Manual 16 July 2014 Page 17 of 40 Quartzlock Model E8 1PPS Series Operation Manual aa 8 bit command repeat interval multiplier Range 1 to 255 Command repeat interval is 40ms x aa RIOaa write new command repeat interval RID cancel command repeat and clear command repeat stack E8 1PPS Series A5 Manual 16 July 2014 Page 18 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix C NMEA 0183 Protocol This appendix provides a brief overview of the NMEA 0183 protocol and describes both the standard and optional messages offered Introduction NMEA 0183 is a simple yet comprehensive ASCII protocol which defines both the communication interface and the data format The NMEA 0183 protocol was originally established to allow marine navigation equipment to share information Since it is a well established industry standard NMEA 0183 has also gained popularity for use in applications other than marine electronics For those applications requiring output only from the GPS receiver NMEA 0183 is a popular choice since in many cases an NMEA 0183 so
11. to the counter set to 1Mohm input impedance Set the delay to Ons The counter should read a delay close to Ons The residual delay can be up to 10ns This is unimportant and is caused by loading effects on the 1PPS output Change the delay in 10ns steps until the vernier setting reads a minimum hex value The delay chip U30 is now set to its minimum delay Step the delay in further 10ns steps Each increment on the counter should be 1043ns When the vernier rolls over the increment on the counter should be 10 5ns If there is a substantial jump at the vernier roll over points the software constant DELAYLINEBITS_PER_NS can be adjusted The software must be re compiled if this is done TEST 1 1PPS output delay control THIS TEST CAN ONLY BE USED IF 1PPS HOLDOVER OPTION IS FITTED This test is exactly the same as TESTO except the delay steps are 100ns This may be useful in debugging the shift register circuit TEST 2 Calibrator check For this test a 1PPS source must be connected to CONNI as otherwise the calibrator will not be operating LED1B should be flashing to show that a 1PPS input is present The calibrator is enabled and continuously displays the results over the interface Four columns are displayed E8 1PPS Series A3 Manual 16 July 2014 Page 34 of 40 Quartzlock Model E8 1PPS Series Operation Manual Averaged 100ns cal Averaged 500ns cal last 100ns cal last 500ns cal 02AE 0B66 02AF 0B66 typical values The averaged v
12. working correctly TEST 4 THIS TEST CAN ONLY BE USED IF 1PPS HOLDOVER OPTION IS FITTED This test is similar to TEST3 however the rate of the 1PPS output is increased to SOPPS This enables an estimate to be made of the jitter in the time expander The interface shows the first capture the second capture and the capture difference The jitter in the capture difference is normally 1 which is 200ps TEST 5 Coarse tune DAC In this test the fine tune DAC is set to OV and the coarse tune DAC is stepped Connect the DC voltmeter between TP5 and ground By using the H and L keys check that the voltage can be stepped between OV and about 4 659V TEST 6 Fine tune DAC In this test the coarse tune DAC is set to midrange and the fine tune DAC is stepped Connect the DC voltmeter between TP5 and ground By using the H and L keys check that the voltage may be stepped over a total range of about 18 2mV TEST 7 OCXO current monitor In this test the OCXO current is continuously displayed The current monitor can be checked by connecting a known resistor from the OCXO supply pin to ground The OCXO current is displayed as a 2 byte hex number Full scale is about 500mA With no resistor i e an OCXO current of zero the maximum offset should be 0600h Connect a 120ohm 1W resistor from an OCXO supply pin C40 to ground The current monitor has a long time constant so at least 30 seconds should be allowed for the reading to stabilise Note the re
13. 3 Samtek TSM 104 01 S DV Pin 1 Ground Pin 5 GPS Port A RS232 TX Pin 2 Ground Pin 6 uP RS232 TX Pin 3 GPS Port A RS232 RX Pin 7 Loopback Pin 4 uP RS232 RX Pin 8 1PPS Output Holdover Option JP4 TE Connectivity 5747840 6 Pin 1 Not Connected Pin 6 Not Connected Pin 2 GPS Port B RS232 RX Pin 7 Not Connected Pin 3 GPS Port B RS232 TX Pin 8 Not Connected Pin 4 Not Connected Pin 9 Not Connected Pin 5 Ground JP5 Eeprom programming connection Link1 Select 1PPS input R Link Position 1 External 1PPS input via CONN1 c Link Position 2 Onboard GPS 1PPS input D Link2 Select 1PPS Output CONN4 CONNS Link Position 1 Onboard GPS 1PPS Direct Output No Holdover Link Position 2 1PPS smoothed output Holdover E8 1PPS Series A5 Manual 16 July 2014 Page 22 of 40 Quartzlock Model E8 1PPS Series Operation Manual Link3 Select controlled oscillator type Link Position 1 OCXO EXT Link Position 2 TCXO Link4 Select controlled oscillator type Link Position 1 OCXO EXT Link Position 2 TCXO Link5 Select controlled oscillator input Link Position 1 External input via CONN8 Link Position 2 Onboard oscillator Link6 Select 1OMHz output CONN6 CONN7 Link Position 1 Sine wave output Link Position 2 Square wave output Link7 Open for 5V oscillator tuning link for 8V oscillator tuning voltage Link8 Select TCXO supply volt
14. A output 9W D Pins 2 amp 4 9 6k baud RS232 8 bits no parity no handshake 2 GPS TSIP 9W D Pins 4 amp 9 9 6k baud RS232 8 bits odd parity no handshake 3 Microprocessor OW D Pins 7 amp 8 9 6k baud RS232 8 bits no parity no handshake INTERFACE CODES Micro processor codes See Appendix B E8 1PPS Series A5 Manual 16 July 2014 Page 12 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix A Board Variation Configuration TCXO Version The following components are not fitted C42 GPS1 R24 R25 R29 TCXO2 U8 U13 U17 U24 U25 U27 U29 U30 U33 U34 U38 U39 VCXO1 VCXO2 VCXO3 Note GPS2 WITH internal clock omit U40 GPS2 WITHOUT internal clock fit U40 Link configuration Link position 2 Link2 position 1 Link3 position 2 Link4 position 2 Link5 not used Link6 position 1 Link7 open Link position 1 OCXO Version without 1PPS holdover and user adjustable 1PPS The following components are not fitted C51 C52 C53 C54 C55 C56 C57 C58 GPS2 L2 L3 LA L5 R39 R40 R41 TCXO1 TCXO2 U13 U17 U24 U25 U27 U28 U29 U30 U33 U38 U39 U40 U41 Link configuration Link position 2 Link2 position 1 Link3 position 1 Link4 position 1 Link5 position 2 Link6 position 1 Link7 short 8V tuning OCXO Version with 1PPS holdover and user adjustable 1PPS The following components are not fitted C51 C52 C53 C54 C55 C56 C57 C58 GPS2 L2 L3 1A L5 R39 R40 R41
15. E8 Series Micro Controller RS232 TX Data Trimble TSIP NO OO SO elt E eS es E8 1PPS Series A5 Manual 16 July 2014 Page 28 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix I Board Test Introduction This board locks an oscillator TCXO OCXO or rubidium oscillator to a 1PPS pulse stream from an integrated GPS receiver The hardware comprises a number of more or less independent sections which require testing on each new board The circuit sections are a 1PPS output circuit b 1PPS time tag circuit c Controlled oscillator tuning supply d GPS module and interfaces e Controlled oscillator f Options The design uses a PIC 18F65K22 microcontroller which is clocked at 1OMHz from the controlled oscillator This ensures the microcontroller internal clock is synchronous with the controlled oscillator By time tagging the incoming 1PPS using the internal clock the frequency difference between the 1PPS input and the controlled oscillator can be measured Frequency corrections are then made to the controlled oscillator The board test uses special test routines that are a permanent part of the operating software General purpose test equipment is used to make manual measurements Circuit Descriptions 1PPS output circuit This part of the circuit is only fitted if an E8 1PPS is built with optional 1PPS holdover The microcontroller generates a rising edge on pin 3 ECCP3 This is generated using an internal pe
16. Quartzlock Model E8 1PPS Series Operation Manual bs Quartzlock model E8000 GPS Disciplined FREQUENCY amp TIME STANDARD ei E8 1 2 2 Series ES E8 E8000 amp E8010 E8000 E8000A GPS Timing amp Frequency Reference USER S HANDBOOK E8 1PPS Series A3 Manual 16 July 2014 Page 1 of 40 Model E8 1PPS Series Operation Manual Revision Date Description By 1 1 Sept 2013 Initial Release N Law la 6 Nov 2013 EEPROM Defaults Issue 1 10 N Law 1b 20 Jan 2014 Provisional E8000 TT E8000A N Law information Ic 5 June 2014 Corrected E8000 TT E8000A N Law D connector pin out information E8 1PPS Series A5 Manual 16 July 2014 Page 2 of 40 Quartzlock Model E8 1PPS Series Operation Manual Contents Ee Ee Ee 4 Voltage Frequency and Power Characteristics cc ccsccececeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeae 5 Environmental Conditions E 5 Replaceable FUSING GWaraCleniSuies aceiiccecccenicianesdaneeleten neat uiaediileceuenatn odhecatanenonentanealeciciaenes 5 Cleaning DE e VE 5 E8 1PPS Series GPS Timing amp Frequency Reference ANEN 6 ACEN T A E E 6 ue Ee E 6 Operations tc se aces ee cette sien ee es eee een 6 AIP MEA ise secre E e E a E E E e S 7 GPS interface E8 X NavSync Version Only 7 Microcontroller Interface E8 1PPS amp E8000 TT E8000A Ont 8 Network Time Protocol Time Server Output EEN ENEE 8 NMEA GSS A GCS EE 8 GPS and Windows Serial Mouse Issue
17. This is the holdover state The 1PPS capture flag is tested to see if the GPS module has resumed fixes and has restored the 1PPS If so state 5 is re entered to restore tracking in the holdover state frequency corrections are inhibited automatically as there are no 1PPS captures The red lock LED is flashed with 50 mark space ratio User Performance Test THIS TEST CAN ONLY BE USED IF 1PPS HOLDOVER OPTION IS FITTED A simple performance test may be made without any equipment The loop back link must be connected to pins 7 and 8 of JP3 This will over ride the 1PPS from the GPS receiver with the internally generated 1PPS As the 1PPS output and the 1PPS time tag are using the same internal clock the Kalman filter will see no frequency offset and no jitter on the 1PPS time tags The performance measure and frequency offset displayed using the PM command should reach limiting low values after about 30 minutes In order to do this test the base time of the 1PPS output should be set to internal clock using the command OSP00 If the base time is set to Kalman estimate or Last input time tag completely random results will occur After the command OSP00 the EEPROM should be updated with the command EU SR may now be used to perform a software reset The quantization correction from the GPS receiver must now be switched off This can be done by setting bit 6 of LOCKSTATUS PM will then displa
18. able length field Degreesminutes decimal 3 fixed digits of degrees 2 fixed digits of minutes and a variable number of digits for decimal fraction of minutes Leading zeros always included for degrees and minutes to maintain fixed length The decimal point and associated decimal fraction are optional if full resolution is not required Fixed Variable length field hoursminutesseconds decimal 2 fixed digits of minutes 2 fixed digits of seconds and a variable number of digits for decimal fraction of seconds Leading zeros always included for hours minutes and seconds to maintain fixed length The decimal point and associated decimal fraction are optional if full resolution is not required Some fields are specified to contain pre defined constants most often alpha characters Such a field is indicated in this standard by the presence of one or more valid characters Excluded from the list of allowable characters are the following that are used to indicated field types within this standard A a c hh hhmmss ss UH x yyyyy yy Variable length integer or floating numeric field Optional leading and trailing zeros The decimal point and associated decimal fraction are optional if full resolution is not required example 73 10 73 1 073 1 73 Fixed length HEX numbers only MSB on the left Fixed length field of upper case or lower case alpha characters Fixed length field of numeric characters The E8 1PPS can output any or al
19. ading convert to decimal divide by 65536 and multiply by 500 This should be the current in mA A typical reading of 33CCh is a current of 101mA The expected accuracy is only about 10 Test 7 is the last programmed test OCXO Output Buffer The OCXO output buffer operates independently of the processor and can be tested as any linear amplifier It has an input impedance of 500ohms and a gain of 1 into a 50 ohm load 1 VRMS at the input should give 1VRMS 13dBm into a 50ohm load To test set source 1 to 1OMHz Check that the input level at CONN8 is 1V RMS Use a high impedance probe for this Adjust the output level of source 1 if necessary Connect an RF power meter to CONN4 or CONNS and check for 13dBm 1dB The buffer 1dB bandwidth should be at least 2MHz to 40MHz This can be checked using a spectrum analyser tracking generator combination if desired This completes the board test To exit the board test software a power on reset must be performed Final Board Configuration The controlled oscillator should be fitted at this stage Reset link 5 as follows OCXO position 2 E8 1PPS Series A5 Manual 16 July 2014 Page 36 of 40 Quartzlock Model E8 1PPS Series Operation Manual TCXO open circuit Reset link to position 2 1PPS from GPS receiver Power up the board with a GPS antenna connected GPS Receiver Configuration The default configuration needs only a few modifications Trimble Resolution SMT Adjust using GPS Stu
20. age Link Position 1 3 3Vdc Link Position 2 5Vdc TP1 1PPS Input TP2 OCXO tuning control voltage output TP3 1PPS Output TP4 TBC TP5 Test Out TP6 Capture TP7 TBC TP8 OCXO current monitor TP9 15Vdc TP10 Ground TP11 External Reference Oscillator Lock Input High 5Vdc Not Locked Low 0Vdc Locked E8 1PPS Series A5 Manual 16 July 2014 Page 23 of 40 Quartzlock Model E8 1PPS Series Operation Manual TP12 Lock LED TP13 1PPS GPS1 fitted or SATS Unused LED GPS2 fitted TP14 SATS Used LED TP15 ON LED TP16 5Vdc TP17 5Vdc Ref TP18 10Vdc TP19 3 3 Vdc TP20 GPS2 site survey finished E8 1PPS Series A5 Manual 16 July 2014 Page 24 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix F EEPROM defaults DEFAULT 0 OCXO medium performance with 0 to 5V tuning Automatically loaded after programming firmware S1 2E 12 S2 3E 11 Rmeas 225E 18 OSCcontrolconstant 2E 7 OSCtunespan 5 0 maxphasedrift0 20000 in nanoseconds DEFAULT 1 OCXO medium performance with 0 to 8V tuning S1 2E 12 S2 3E 11 Rmeas 225E 18 OSCcontrolconstant 2E 7 OSCtunespan 8 0 maxphasedrift0 20000 in nanoseconds DEFAULT 2 TCXO low performance with 0 to 3 3V tuning NavSync receiver S1 2E 11 S2 3E 10 Rmeas 2 5E 15 OSCcontrolconstant 5E 6 OSCtunespan 3 3 maxphasedrift0 200000 in nanoseconds DEFAULT 3 Rubidium high performance with 0 to 5V tuning
21. alues will slowly approach the spot values due to the long time constant of the filter A maximum jitter of 1 is normal on the spot values As a further check on the time expander an oscilloscope with a divide by 10 probe should be connected to TP4 Groups of 2 saw tooth ramps should be observed each group repeating every 20ms One group should be expanded The first ramp is the expansion of the 100ns calibration pulse and the second is the expansion of the 500ns calibration pulse The following voltage measurements should be made using the oscilloscope cursor Ramp start voltage 2 0V 0 1V First ramp peak voltage 3 0V 0 2V Second ramp peak voltage 8 0V 0 4V If the voltages are incorrect there may be an incorrect component around the time expander circuit TEST 3 1PPS capture check NOTE If 1PPS holdover option is not fitted this test cannot be used directly as the internal 1PPS source is not available An external 1PPS source must be used This must be synchronous with the processor clock and must have very low jitter A spare A6 1PPS board can be used with the 10MHz input connected to the 1OMHz output of the E8 1PPS board under test The 1PPS input should be connected to CONN1 An A6 frequency converter digital board may also be used PROCEDURE IF 1PPS HOLDOVER OPTION IS FITTED The 1PPS output is used as a pulse generator to test the 1PPS capture The 1PPS output should be connected to the 1PPS input A link should be made betw
22. dentical to that used in the A6 CPS A dual 16bit DAC is used to generate a tuning voltage in the range 0 to 5V The fine tune DAC output is divided by 256 and added to the output of the coarse tune DAC There is provision for two different dual DACs to be fitted U23 is a lower cost option and U24 is lower noise for use with the lowest phase noise OCXOs U21 provides DC gain to increase the maximum tuning voltage to about 8V Two tuning voltage ranges are provided 0 to 5V with link7 open and 0 to 8V with link7 closed GPS receiver and interfaces Provision is made for either a Trimble Resolution SMT or a NavSync CW25 TIM GPS receiver to be fitted It is intended that the Resolution SMT GPS1 should be used in all builds of the E8 1PPS The CW25 TIM GPS2 can be used in builds of the E8 X 1PPS Two versions of the CW25 can be used with or without internal TCXO clock Each GPS receiver has two serial ports The default for GPS1 is that port A is TSIP binary This must not be changed as the microcontroller monitors packets on this interface Port B can be set to either TSIP or NMEA as covered in the board setup described later Port A is connected to header JP3 pins 3 RxD and pin 5 TxD Port B is connected to the 9 way D connector JP4 pins 2 RxD and pin 3 TxD The default for GPS2 is Port 0 is Motorola binary protocol and Port 1 is NMEA Port 0 is connected to JP3 and Port1 to JP4 The microcontroller interface is connected to JP3 p
23. dio 1PPS output mode set to 1PPS only output if 1 or more satellites tracked Packet masks Set Primary timing packet 8F AB Supplemental timing packet 8F AC and Auto event packets on Port B may be set to NMEA or TSIP as desired NOTE After changes the configuration MUST be saved otherwise the unit will return to the previous settings after power down NavSyne CW 25 TIM Adjust using WinOncore Run E8 TXT Send Gc02 1PPS on when tracking 1 or more satellites The Trimble Resolution SMT will do a self survey when first powered up at a new location Further power ups at the same location will not result in a new self survey The NavSync CW25 TIM will always perform a self survey on power up Controlled Oscillator Auto Calibration When new firmware is loaded EEPROM default 0 is automatically loaded This is an OCXO with 5V tuning If an alternative controlled oscillator is fitted then the appropriate EEPROM default must be loaded It is essential that the physical tuning voltage range adjusted with Link 7 should match the tuning voltage range stored in the EEPROM and loaded by the EEPROM default command This can be checked using the OC command When the EEPROM default is loaded a flag is set to indicate that OCXO calibration is required The software will attempt to get lock on the 1PPS from the GPS receiver in the normal way going through states 0 1 2 and 3 When the normal running state 4 is ente
24. e matrix P11 P12 P13 P22 P23 P33 in floating point format KPxx space string carriage return inputs a new floating point value where xx identifies matrix element KP write KP to command repeat stack System covariance matrix KQ returns current system covariance matrix Qll Q12 013 022 023 Q33 Note Q matrix is calculated from system noise parameters on reset and also in states 2 3 and 5 System state vector KX returns current system state vector XI X2 X3 Note X1 is current phase estimate X2 is current frequency estimate and X3 is current drift estimate KX write KX to command repeat stack System noise parameters KS returns current system noise parameters S1 S2 Note S1 is the level of random walk FM noise and S2 the level of white FM noise These are fixed parameters that describe the oscillator being modelled KSx space string carriage return inputs a new floating point value where x is the matrix element Measurement parameters KZ returns the latest measurement and the current measurement noise parameter E8 1PPS Series A5 Manual 16 July 2014 Page 16 of 40 OC OT CA EU ED SR ER EW DR WF Quartzlock Model E8 1PPS Series Operation Manual Z Corrected Timetag Correction R Note Z is the last measurement in seconds Timetag is the uncorrected Timetag in ns Correction is the quantization correction decoded from the GPS receiver in ns R is the expected variance of the measurement noise
25. een pins 7 and 8 of JP3 This connects the 1PPS output to the time expander input overriding the 1PPS from the GPS module PROCEDURE IF 1PPS OPTION IS NOT FITTED Connect synchronous 1PPS input to CONN1 After each pulse the interface will display the 1PPS user delay signed decimal in ns followed by the 5 parameters output by the TO command These are Last time tag decimal ns First capture hex Second capture hex Capture difference hex Modulo50 counter hex If channel 2 of the oscilloscope is transferred to TP4 the integrator output may be observed The Capture difference should show a maximum jitter of 1 which is 200ps The Last time tag is rounded to the nearest Ins The actual value of the Last time tag depends upon the reset point of the internal clock and is not significant NOTE If PPS holdover option is not fitted following procedure cannot be used as 1PPS source delay is not adjustable As the PPS output delay is stepped using the H and L keys the time tag should step with the same 10ns increments Note that any nonlinearity detected in TESTO will also appear in this test E8 1PPS Series A3 Manual 16 July 2014 Page 35 of 40 Quartzlock Model E8 1PPS Series Operation Manual The key point to look for is when the first capture changes by integer 1 This represents an overflow of the time expander and is the point where a jump in the time tag might be expected if the calibration was not
26. efault using NavSync CW25 device In this case state 0 is only exited when CW25 has finished its site survey and set its ready line high STATE 1 State 1 is waiting for the internal clock to be reset A timeout is started If no clock reset is acknowledged in second state 0 is re entered Red lock LED is permanently on STATE 2 The internal clock has been synchronized on the first 1PPS capture Red lock LED is permanently on The Kalman filter should now be tracking the incoming 1PPS although no frequency corrections are being made In this state and state 3 the Kalman filter is made adaptable to the real behaviour of the system The performance measure filteredfreqerror is used to modify the random walk noise parameter which describes the controlled oscillator This is S1 The frequency error is high so the effective filter bandwidth is too narrow to track warm up drift of the oscillator The scaling parameter of S1 Slscale which is the random walk FM noise root variance normally preset to 1 is increased according to the value of the filtered frequency error ratio After each change to SIscale the Q matrix is recalculated This state is exited after 100 successful 1PPS captures and if the frequency drift is less than a threshold If captures stop after a time out state 0 is entered STATE 3 In this state the Red lock LED flashes rapidly The error monitor parameter filteredfreqerror is compared with a threshold when it
27. eld contains two ASCII characters which indicate the hexadecimal value of the checksum CR LF The carriage return CR and line feed LF combination terminate the message E8 1PPS Series A5 Manual 16 July 2014 Page 19 of 40 Model E8 1PPS Series Operation Manual NMEA 0183 messages vary in length but each message is limited to 79 characters or less This length limitation excludes the and the CR LF The data field block including delimiters is limited to 74 characters or less Field definitions Many of the NMEA date fields are of variable length and the user should always use the comma delineators to parse the NMEA message date field The following table specifies the definitions of all field types in the NMEA messages supported by the E8 1PPS Status A Single character field A Yes data valid warning flag clear V No data invalid warning flag set Special Format Fields Latitude IL Fixed variable length field Degreesminutes decimal 2 fixed digits of degrees 2 fixed digits of minutes Longitude yyyyy yyy Time hhmmss ss Defined Numeric Value Fields Variable D I Fixed HEX hh Information Fields Fixed Alpha aa Fixed Number XX NMEA 0183 message options and a variable number of digits for decimal fraction of minutes Leading zeros always included for degrees and minutes to maintain fixed length The decimal point and associated decimal fraction are optional if full resolution is not required Fixed Vari
28. ftware application code already exists The E8 1PPS is available with firmware that supports a subset of the NMEA 0183 messages GGA GLL GSA GSV RMC VTC and ZDA NMEA 0183 communication interface NMEA 0183 allows a single source talker to transmit serial data over a single twisted wire pair to one or more receivers listeners The table below lists the standard characteristics of the NMEA 0183 data transmissions Signal NMEA Standard Baud rate 9600 Data bits 8 Parity None Disabled Stop bits 1 NMEA 0183 message structure The NMEA 0183 protocol covers a broad array of navigation data This broad array of information is separated into discrete messages which convey a specific set of information The entire protocol encompasses over 50 messages but only a sub set of these messages apply to the E8 1PPS GPS receiver The NMEA message structure is described below IDMSG D1 D2 D3 D4 Dn CS CR LF Signifies the start of a message ID The talker identification is a two letter mnemonic which describes the source of the navigation information The GP identification signifies a GPS source MSG The message identification is a three letter mnemonic which describes the message content and the number and order of the data fields Commas serve as delimiters for the data fields Dn Each message contains multiple data fields Dn which are delimited by commas The asterisk serves as a checksum delimiter CS The checksum fi
29. ge 29 of 40 Quartzlock Model E8 1PPS Series Operation Manual 1PPS time tag circuit This is the most complicated of the three circuit blocks It can time tag the incoming 1PPS rising edge to a resolution of Ins It does this by a combination of an internal capture module ECCP2 and a pulse width expander After the first 1PPS the processor has a near exact knowledge of when the next and subsequent 1PPS edges will arrive It prepares for a new edge by setting the ready line pin 48 high This will occur between 20 and 40ms before the next 1PPS edge Initially D types U4A U4B U9A and U9B are reset Multiplexer U3 is configured to pass the incoming 1PPS to the clock input of U4A so the 1PPS edge will set U4A The processor pin 40 CLKO has a square wave at 2 5MHz synchronized to the processor internal cycle clock The first falling edge of CLKO will set U4B clock is inverted by U11 The next rising edge of the 1OMHz clock will then set U9A When U9A Q goes high an internal capture is generated in the processor via OR gate U12 and the ECCP2 input pin This capture provides an internal hardware read of the internal clock register As the 1PPS input is asynchronous the time between the setting of U4A and U4B will vary between Ons and 400ns depending on the phase of the 1PPS relative to the processor internal cycle clock U9A is always set 100ns after U4B And gate U15 generates a pulse between 100ns and 500ns by anding the Q output of U4A
30. ime between the 2 captures with a resolution of 400ns Because of the 2000 times expansion of the integrator the basic resolution is 200ps When the comparator output goes high U9B is reset via U7 reconnecting the stabilization circuit ready for the next expansion Calibration The pulse expander is an analogue circuit which can drift It needs calibration so the range of the expanded pulse can be exactly referred to the 100 to 500ns unexpanded pulse The calibration operates by generating pulses of exactly 100ns wide and 500ns wide by gating the 1OMHz clock These calibration pulses are expanded and measured The results can then be used to correct measurements of the 1PPS input E8 1PPS Series A3 Manual 16 July 2014 Page 30 of 40 Quartzlock Model E8 1PPS Series Operation Manual The calibration operates every 20ms when the 1PPS input is not expected Each calibration cycle generates a pulse of 100ns and 500ns which are measured If the CAL_ON line on pin 47 of the processor is set high before the READY line is set high gate U3 routs the clock input of U4A to the inverted CLKO line This makes the D type chain generate the calibration pulse The 500 100ns line and gate U18 controls the width of the calibration pulse The processor averages the calibration readings in a long time constant filter The filtered results are used to correct each 1PPS timetag Controlled oscillator tuning supply The controlled oscillator supply is nearly i
31. in 4 RxD and pin 6 TxD LED Interface When GPS1 is fitted the microcontroller decodes packet 6D which contains the number of satellites currently used in the over determined time solution LED1A is flashed to indicate this number LED 1B is flashed each time a 1PPS pulse is received by the microcontroller LED2B is the lock indicator which has a number of flash codes described later LED2A is the power on LED When GPS2 is fitted R24 and R25 are omitted R39 and R40 are fitted which connect LED1A and LED 1B directly to the internal LED interface in GPS2 These LEDs then flash to show the number of satellites tracked and the number used in the time solution Controlled oscillator The controlled oscillator is intended to be an OCXO in E8 1PPS variants and a TCXO for the E8 X 1PPS A rubidium oscillator may also be used For OCXO variants link5 is set to position 2 The OCXO sine output is applied to comparator U3 1 The anti phase square wave outputs are the processor clock and the 1PPS output circuit clock Links 3 and 4 are set to position 1 For TCXO variants link8 is set to position 1 for 3 3V supply and position 2 for 5V supply to the TCXO The TCXO frequency is 20MHz and is applied to comparator U31 U28 divides the TCXO frequency by 2 and the anti phase 10MHz signals are selected by links 3 and 4 set to position 2 E8 1PPS Series A5 Manual 16 July 2014 Page 31 of 40 Quartzlock Model E8 1PPS Series Operation Manual For
32. in seconds squared KZ1 space string carriage return inputs anew R KZ write KZ to command repeat stack Oscillator control parameters OC returns latest oscillator control constant and maximum tuning voltage OC OC7 Note OCT is oscillator tuning constant in fractional frequency volt and OC2 is the maximum tuning voltage in volts assumed OV minimum OCx space string carriage return inputs new OC1 or OC2 where x is the parameter Oscillator tuning control OT returns tuning word and DAC values aaaaaa bbbb cccc aaaaaa 24 bit tuning word bbbb coarse tuning DAC value cccc fine tuning DAC value OTTaaaaaa inputs new tuning word OT writes OT to command repeat stack Auto cal parameters CA returns auto cal parameters aaaa bbbb cccc dddd aaaa filtered CAL100ns value bbbb filtered CAL500ns value ccce last CAL100ns value dddd last CAL500ns value EEPROM update backed up values from RAM load EEPROM and RAM with default values EDa loads EEPROM with default a a 0 default automatically loaded after new firmware a 2 9 parameters for other oscillator types defined in firmware Software Reset EEPROM read ERCaaaabb returns bb bytes from starting address aaaa as ASCII characters ERNaaaabb returns bb bytes from starting address aaaa as hexadecimal numbers character pairs EEPROM write EWCaaaabbccccc c writes bb characters to starting address aaaa Correct number of characters must be included in
33. ith commas and ending with lt CR gt lt LF gt Approved sentences are recognized by the first 5 characters after the which define both the kind of talker providing the information 2 characters GP in the case of a GPS and the type of information 3 characters Proprietary sentences are indicated by a P following the as the first of the 5 characters the next 3 indicating the manufacturer from a listing of mnemonic codes and the 5th character being selected by that manufacturer for the particular sentence structure Proprietary sentences must conform to the general NMEA structures but are otherwise undefined outside of the Manufacturers own documentation The following Approved messages are available from the receiver GPGLL Geographic Position Latitude longitude GPGGA Global Positioning System Fix Data GPGSA GNSS DOP and Active Satellites GPGSV GNSS Satellites in View GPRMC Minimum required sentence GPGLL Geographic position Lat Lon Latitude and longitude with time of position fix and status GPGLL Latitude N Longitude E hhmmss sss Status Mode cs GPGLL NMEA sentence header Position Data Latitude User datum latitude degrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North or S South Longitude User datum longitude degrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East or W West hhmmss sss UTC Time in hours minutes
34. l of the messages listed in the table below Typically NMEA messages are output at a 1 second interval with the GP talker ID and checksums These messages are output at all times during operation with or without a fix GGA GLL GSA GSV RMC VTG ZDA GPS fix data Geographic position Latitude Longitude GPS DOP and active satellites GPS satellites in view Recommended minimum specific GPS Transit data Track made good and ground speed Time and date E8 1PPS Series A5 Manual 16 July 2014 Page 20 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix D TSIP Protocol Please refer to the Trimble Website Resolution SMT GG User Guide Trimble VTS Software E8 1PPS Series A5 Manual 16 July 2014 Page 21 of 40 Quartzlock Model E8 1PPS Series Operation Manual Appendix E Connector Jumper and Link References CONNT External 1PPS Input MCX CONN2 GPS Antenna Input BNC Optional TNC CONN3 GPS Antenna Input SMA not fitted if CONN3 fitted CONN4 1PPS Output BNC CONNS5 1PPS Output MCX not fitted if CONN4 fitted CONN6 10MHz RF Output Sine Square MCX SMA not fitted if CONN7 fitted CONN7 10MHz RF Output Sine Square BNC CONNS8 External 1OMHz RF Input MCX SMA Ji Lumberg 1613 14 15Vdc Input JP2 Samtek TSM 103 01 S DV Pin External reference tune output Pin 4 Ground Pin 2 External reference lock input Pin 5 Not Connected Pin 3 Ground Pin 6 Not Connected JP
35. lt from failure to heed a caution Do not proceed beyond a caution until the indicated conditions are fully understood and met This equipment must be earthed An uninterruptible safety earth ground must be maintained from the mains power source to the product s ground circuitry WARNING When measuring power line signals be extremely careful and use a step down isolation transformer whose output is compatible with the input measurement capabilities of this product The product s front and rear panels are typically at earth ground Thus never try to measure AC power line signals without an isolation transformer WARNING Instructions for adjustments when covers are removed and for servicing are for use by service trained personnel only To avoid dangerous electrical shock do not perform such adjustments or servicing unless qualified to do so WARNING Any interruption of the protective grounding conductor inside or outside the instrument or disconnecting of the protective earth terminal will cause a potential shock hazard that could result in personal injury Grounding one conductor of a two conductor out let is not sufficient protection Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation If the instrument is to be energised via an autotransformer for voltage reduction makes sure the common terminal i
36. mA maximum warm up A universal line power supply is provided Operation The unit is fully programmed to operate without adjustment anywhere in the world The GPS receiver will take about 1 minute to obtain a fix from a cold start with unknown location The receiver then does a site survey for about 15 minutes averaging the positions obtained After the site survey is complete the receiver switches to position hold mode and uses all the satellites available to improve the accuracy of the time calculation At this point the unit will lock its 20MHz reference oscillator to the GPS signal This only takes a few seconds Desk top when the PLL locks the red lock LED should go out but may flash for a further minute as the PLL settles The normal operating condition is with the red lock LED off Rack mount when the PLL locks the ON LED will change from amber to green but may flash amber for a further minute as the PLL settles The normal operating condition is with the ON LED green The status of the satellite tracking is shown by the SATS USED LED The normal situation is that the LED shows a long flash followed by a number of short flashes The number of short flashes shows the number of satellites being tracked and included in the time solution E8 X Only the Lower LED may also flash This shows the number of satellites being tracked but not included in the timing solution All other variants the lower LED flashes once ever
37. mv mvd Mode cs GPRMC NMEA sentence header Recommended Minimum Sentence hhmmss sss UTC Time in hours minutes seconds status Status V navigation receiver warning A data valid Latitude User datum latitude degrees minutes decimal minutes format ddmm mmmmmm E8 1PPS Series A3 Manual 16 July 2014 Page 9 of 40 Quartzlock Model E8 1PPS Series Operation Manual N Hemisphere N North or S South Longitude User datum longitude degrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East W West spd Speed over ground knots cmg Course made good ddmmyy Date in Day Month Year format mv Magnetic variation mvd Magnetic variation direction Mode Mode Indicator D Valid Differential A Valid Autonomous E Invalid Estimated N Invalid Not Valid cs Message checksum in hexadecimal GPS and Windows Serial Mouse Issue Problem It is possible for windows to incorrectly interpret the data output from the Quartzlock GPS interface as the output of a Microsoft Serial BallPoint Mouse When that happens Windows loads drivers for the Serial BallPoint Mouse This causes the cursor to move erratically about the display clicking right clicking double clicking dragging and dropping display items as it goes On Windows 2000 XP and Vista you may not experience the problem if you wait until after the computer is booted before connecting the Quartzlock GPS to the serial comm
38. on and DOP values GPGSA Smode FS sv sv SV eu PDOP HDOP VDOP cs GPGSA NMEA sentence header Satellite Data Smode A Automatic switching 2D 3D M Manually fixed 2D 3D FS Fix Status 1 No fix 2 2D GPS Fix 3 3D GPS Fix SV Satellites in use null for unused fields 12 available fields PDOP 3 D Position Dilution of Precision 0 00 to 99 99 HDOP 2 D Horizontal Dilution of Precision 0 00 to 99 99 VDOP Vertical Dilution of Precision 0 00 to 99 99 cs Message checksum in hexadecimal GPGSV GPS Satellites in View The number of satellites in view together with each PRN elevation and azimuth and C No value Up to four satellite details are transmitted in one message with up to three messages used as indicated in the first field GPGSV NoMsg MsgNo NoSv sv elv az cno sv elv az cno cs Note designate optional sections that appear only if there is satellite data GPGSV NMEA sentence header Satellite Data NoMsg Total number of GPGSV messages being output MsgNo Number of this messages NoSv Number of satellites in view SV Satellites ID elv Satellite elevation angle degrees az Satellite azimuth angle degrees cno Satellite signal Noise ratio dB Hz cs Message checksum in hexadecimal GPRMC Recommended Minimum data The Recommended Minimum sentence is defined by NMEA for GPS Transit system data GPRMC hhmmss sss status latitude N Hemisphere longitude E spd cmg ddmmyy
39. point last IPPS quantization correction TO write TO to command repeat stack PERFORMANCE MEASURE PM returns last time tag in decimal ns and other performance indicators a fp string b fp string cccccccc dddd eeee f fp string g fp string a floating point Corrected time tag b floating point Last Kalman phase estimate COOC Mean square measurement error ns squared decimal integer ddddd Filtered performance indicator 0 to 32768 decimal integer eeeee S1 multiplier decimal integer f floating point Frequency estimate and correction g floating point Mean of frequency estimate PM write PM to command repeat stack Notes The performance indicator is the square of the current fractional frequency estimate divided by the P22 element of the error covariance matrix multiplied by 2048 The normal running value is 0 to 100 The mean square measurement error is the Kalman phase estimate minus the current time tag 2 and filtered in an 8th order exponential filter Units are ns 2 The S1 multiplier is the constant used to multiply the S1 system noise parameter random walk FM This results in a recalculation of the Q matrix system covariance matrix This adjusts the filter for expected increased drift rate of the controlled oscillator The mean of the frequency estimate is the Kalman frequency estimate filtered by a 5th order exponential filter Kalman filter error covariance matrix KP returns current error covarianc
40. r further details Ge01 Enable 1PPS output when gt 1 satellite is being tracked consult the CW12 user manual for further details Gc02 Set the alarm threshold for the T RAIM algorithm 300ns Consult the CW12 user manual for further details Gf0003 Request channel T RAIM status message sent every second Hn01 If required the position status data message may be turned on Ha0l1 E8 1PPS Series A3 Manual 16 July 2014 Page 7 of 40 Quartzlock Model E8 1PPS Series Operation Manual If required the visible satellites message may be switched on Bb01 The GPS receiver stores the current status in non volatile memory when switched off Microcontroller Interface E8 1PPS amp E8000 TT E8000A Only The microcontroller interface allows setup and debug of the digital phase lock loop which locks the 20MHz reference oscillator to the GPS receiver The list of control codes is given in an appendix Network Time Protocol Time Server Output The NTP Time server output provides a simple method of putting accurate time information onto a network In order to use this a freeware program such as Tardis 2000 should be installed on the user s PC Connect the unit to the PC and start the program It may be necessary to set the port and baud rate 9600 NMEA Messages There are two main types of sentence Approved and Proprietary All sentences start with delimited w
41. re bt set loads EEPROM default 0 then cleared bitl set initiates auto OCXO calibration then cleared bit2 set when OCXO cal is in progress bit3 NU bit4 7 last EEPROM default number eeee is OCXO current 0000 to FFFF 0 to 500mA DI is running time 0000 to FFFF unit 18 2 hours OSTaa write new test status byte OSLbb write new lock status byte OSPcc write new output 1PPS status byte OSAdd write new autocal byte PO 1PPS OUT PO returns current status of 1PPS output aa bbbb cc dd aa modulo50 counter 20ms range 0 to 49 bbbb main counter 400ns range 0 to 49999 C34Fh cc delay setting SOns range 0 to 8 delay 50 to 450ns dd vernier 0 25ns range 0 to 255 POAaa write new modulo50 counter POBbbbb write new main counter POCcc write new delay setting PODdd write new vernier PD 1PPS OUT PD returns current user 1PPS offset in decimal ns aaaaaaaaa aaaaaaaaa last user 1PPS offset 500 000 000 to 499 999 999 ns PD space string carriage return inputs new user 1PPS offset in floating point format e g to set the offset to 500ns delay PD 000000500 TO TIMETAG E8 1PPS Series A3 Manual 16 July 2014 Page 15 of 40 PM KP KQ KS KZ Quartzlock Model E8 1PPS Series Operation Manual TO returns last time tag parameters aaaaaaaa bbbb cccc dddd ee Up string daaaaaaaa Last time tag 32 bit bbbb first capture cece second capture dddd second capture first capture ee Modulo50 capture f floating
42. red the software will immediately enter the special OCXO calibration routine This is shown by a message over the interface The following actions then happen a The Kalman filter frequency correction is stopped b The OCXO tuning is offset by about 10 of the total c The Kalman frequency estimate is reset to enable rapid acquisition of the new frequency d The command PM is written to the command repeat stack to provide user monitoring Over a period of about 5 minutes the filter will acquire the new frequency From knowledge of the voltage offset applied to the tuning voltage and the frequency shift that this has produced the tuning constant of the oscillator can be calculated as a fractional frequency volt This parameter is E8 1PPS Series A5 Manual 16 July 2014 Page 37 of 40 Quartzlock Model E8 1PPS Series Operation Manual then written to EEPROM to replace the default tuning constant The new tuning constant may be viewed with the OC command After the calibration is complete the unit will go back to state 0 and should lock normally State Control The following information has been copied from the software listing to provide more information on the state control STATE 0 State 0 is the first state after cold start Red lock LED is permanently on The state is exited only when a The rubidium is locked OR b The OCXO has warmed up c A 1PPS capture has been received Test for oscillator type eeprom d
43. ripheral capture compare module when the internal clock equals the setting of the 1PPS output delay register The delay register is settable by the PD command The internal resolution of this edge is 400ns One processor cycle at a clock frequency of 1OMHz In order to provide Ins delay resolution the rising edge is further delayed by the shift register U25 and the analogue delay chip U30 U25 shifts the rising edge into the shift register on each selectable rising or falling edge of the processor clock exclusive OR gate U29 provides the clock inversion Each output of the shift register provides a delayed and re clocked rising edge with successive delays of 100ns Inversion of the clock shifts all the delayed outputs by 50ns U27 is a 16 to 1 multiplexer that selects one of the edges under control of the 4 bit address provided by the microcontroller Bit O of the address is used to invert the clock Bits 1 to 3 are used to select the delayed edge The minimum delay is 50ns and the maximum used is 450ns The output on pin 5 of U27 is then applied to U30 U30 is a standalone delay chip that provides delay increments of approximately 0 25ns steps from 0 to 63ns There is a fixed delay of about 20ns Using the three delay mechanisms the processor can calculate appropriate settings to delay the 1PPS output 500000000 to 499999999 ns in Ins steps An internal timer terminates the 1PPS pulse after 10ms E8 1PPS Series A5 Manual 16 July 2014 Pa
44. rubidium versions link 5 is set to external 1 OMHz position 1 The rubidium output is applied to CONNS The rubidium tuning voltage is at pin 1 of connector JP2 Pin 2 of JP2 is a rubidium locked signal to the processor active low For OCXO variants U8 is the 12V regulator for the OCXO U34 provides a current monitor to the processor analogue input pin 27 OCXO warm up is detected by a reduction in OCXO current below a threshold Options Various hardware options are provided for future expansion Low noise tuning DAC U23 will normally be fitted This is a low cost dual 16 bit DAC For use with the lowest phase noise OCXOs U24 may be fitted This is the lowest noise dual 16bit DAC available Traceability memory U13 is a 1Mbyte flash memory This may be used to store status data to prove correct locking to GPS time over an extended period Temperature sensor U39 is a temperature sensor This is intended for implementation of a more elaborate OCXO holdover algorithm Required Equipment a source 1 10OMHz fixed frequency accuracy 1E 6 level 1V RMS EMF adjustable b DC voltmeter 5 digit resolution c 2 channel oscilloscope preferably digital storage d Frequency counter capable of time interval measurement with a resolution of at least Ins e RF power meter 50ohm Board Set Up A new board should be configured by setting various links These are solder links Refer to the build summary document for the various link connection
45. s It is assumed that a new board is first tested without the controlled oscillator fitted Power up the board from a regulated supply set to 15v Supply current will depend upon build configuration Supply LED LED 1B green should light Programming Connect the programmer to JP5 and load the latest version firmware Board power must be on In case of problems check the Vdd supply at C47 SV 0 15V Power Supplies Check a 10V 0 3V at TP18 b Vdd 5V 0 15V at C47 c 5V 0 1V at TP16 d 12V 0 3V at U8 pin3 e 5V ref 5V 5mV at TP17 E8 1PPS Series A5 Manual 16 July 2014 Page 32 of 40 Quartzlock Model E8 1PPS Series Operation Manual Board Functional Tests Power down the board Set the solder links as follows OCXO variants 1 position 1 external 1PPS 2 position 1 1PPS holdover option NOT fitted position 2 1PPS option fitted 3 position 1 4 position 1 5 position 1 external 1 OMHz 6 optional to suit build specification sine or square 1OMHz output 7 To suit OCXO tuning range 8 Not Used TCXO variants 1 position external 1PPS 2 position 1 note that 1PPS holdover option cannot be fitted to TCXO versions 3 position 2 4 position 2 5 position 1 external 1 OMHz 6 optional to suit build specification 7 open circuit 5V tuning 8 to suit TCXO supply voltage Connect source 1 to CONN8 and set to 10MHz 1VRMS EMF The processor should now be clocked from this source LED2B red should be continuo
46. s connected to the earthed pole terminal neutral of the power source Instructions for adjustments while the covers are removed and for servicing are for use by service trained personnel only To avoid dangerous electrical shock do not perform such adjustments or servicing unless qualified to do so E8 1PPS Series A5 Manual 16 July 2014 Page 4 of 40 Quartzlock Model E8 1PPS Series Operation Manual For continued protections against fire replace the line fuse s with fuses of the same current rating and type for example normal blow time delay Do not use repaired fuses of short circuited fuse holders Voltage Frequency and Power Characteristics AC Power Adaptor Rack mount units excluding E8010 Voltage 100 240V AC Frequency 40 60Hz Power characteristics 700mA Max Voltage 15V DC 300mA 1700mA AC Plug Top Adaptor Desk top units Voltage 100 240V AC Frequency 50 60Hz Power characteristics 6 00mA Max Voltage 15V DC 1 2A Environmental Conditions Temperature Operating ambient 10 C to 55 C 65 to 65 option Storage 40 C to 85 C Magnetic Field Sensitivity lt 2x10 Gauss Atmospheric Pressure 60m to 4000m lt 1x101 mbar Replaceable Fusing Characteristics Rack mount units 800mA time lag HBC Cleaning Instructions To ensure long and trouble operation keep the unit free from dust and use care with liquids around the unit Be careful not to spill liquids onto the unit If the unit does get wet
47. se Per Second POWER SUPPLY 100 to 240 AC 700mA Rack Mount 12 to 15V DC 250mA 1500mA Desk Top DPLL tracking bandwidths 5mHz to 500mHz typical in 8 binary increments Default 20mHz LOCK INDICATOR Desk Top On not locked Off locked low phase error Short flash every second locked high phase error ON INDICATOR Rack Mount Amber not locked Green locked low phase error Short amber flash every second locked high phase error GPS INDICATOR Desk Top SATS USED indicates no of satellites used in time solution 1PPS Flashes when 1PPS signal is present GPS INDICATOR Rack Mount Green indicates no of satellites used in time solution Red Flashes when 1PPS signal is present INTERFACE The E8 1PPS has 3 RS232 interfaces 1 NMEA output JP4 9 6k baud RS232 8 bits no parity no handshake 2 GPS TSIP JP3 9 6k baud RS232 8 bits odd parity no handshake 3 Microprocessor JP3 9 6k baud RS232 8 bits no parity no handshake The E8 X amp E8 Y has 1 RS232 interface 1 NMEA output JP4 9 6k baud RS232 8 bits no parity no handshake The E8000 has 3 Optional RS232 interfaces 1 NMEA output JP4 9 6k baud RS232 8 bits no parity no handshake E8 1PPS Series A5 Manual 16 July 2014 Page 11 of 40 Quartzlock Model E8 1PPS Series Operation Manual 2 GPS TSIP JP3 9 6k baud RS232 8 bits odd parity no handshake 3 Microprocessor JP3 9 6k baud RS232 8 bits no parity no handshake The E8000 TT E8000A has 3 RS232 interfaces 1 NME
48. seconds and decimal seconds format Status Status V navigation receiver warning A data valid Mode Mode indicator A Valid Autonomous D Valid Differential E Invalid Estimated N Invalid Not valid cs Message checksum in hexadecimal GPGGA GPS fix data Time and position together with GPS fixing related data E8 1PPS Series A3 Manual 16 July 2014 Page 8 of 40 Quartzlock Model E8 1PPS Series Operation Manual GPGGA hhmmss sss Latitude N Longitude E FS NoSV HDOP Altref M msl M DiffAge DiffStation cs GPGGA NMEA sentence header Position Data hhmmss sss UTC Time in hours minutes seconds and decimal seconds format Latitude User datum latitude degrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North or S South Longitude User datum longitude degrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East W West FS Fix Status 0 No fix 1 Standard GPS 2 Differential GPS NoSV Number of satellites used in the position solution HDOP 2 D Horizontal Dilution of Precision 0 00 to 99 99 AltRef Altitude metres above user datum ellipsoid M Units of height metres msl Mean Sea Level M Units of Mean Sea Level meters DiffAge Age of differential correction DiffStation Differential base station ID cs Message checksum in hexadecimal GPGSA GPS DOP and Active satellites GPS receiver operating mode satellites used for navigati
49. unications port This problem is not specific to Quartzlock GPS Any NMEA Binary output device connected to a Windows computer s serial port is likely to cause this problem Below are several possible solutions to this problem Solution 1 The easiest solution is to disable the Serial BallPoint mouse in the Device Manager Of course this solution assumes that you do not need to use a Serial BallPoint mouse with your computer When the wild mouse problem occurs follow the steps below 1 Unplug the DB9 connector 2 Right click the My Computer icon on your desktop and select Properties to open the Device Manager 3 Go to the hardware tab of the resulting pop up window and click on the Device Manager button 4 Right click on Serial BallPoint Mouse and choose the option to Disable NOT uninstall this device Solution 2 Do not plug the DB9 connector into the computer until the computer is turned on and the operating system is completely booted and running Every time you use the Quartzlock GPS you will need to start the computer and operating system before making the connection between the Quartzlock GPS and the computer This solution normally works on Windows 2000 XP and Vista computers E8 1PPS Series A3 Manual 16 July 2014 Page 10 of 40 Quartzlock Model E8 1PPS Series Operation Manual Specifications OUTPUTS Sine wave 1OMHz 12dBm 2dBm into 50ohms Harmonics lt 50dBc Spurii lt 75dBc TTL 3 3V CMOS 1 Pul
50. usly on If it is flashing the processor is not getting an external clock Check U31 U28 TCXO version Link3 4 Operation of the interface must first be checked Connect a PC with RS232 to JP3 Only pins 6 TXD pin4 RXD and pin 2 ground need to be connected Start a general terminal program set the interface to 9600baud Istart bit no parity and check that the microcontroller responds to commands by sending OS Connect a second RS232 port to JP3 Only pins 5 TXD pin3 RXD and pin 1 ground need to be connected Start the appropriate GPS control software This is Trimble GPS Studio or NavSync WinOncore The GPS receiver should start operating within a few seconds of power up and should communicate with the control program The EEPROM must be set to default values using command EDx to match the controlled oscillator type fitted See Appendix F for EEPROM defaults This only needs to be done after reloading the firmware If the 1PPS holdover option is not fitted connect the external PPS source to CONN at this point LED1B should flash at a 1Hz rate The state should change to S1 and then S2 The board test E8 1PPS Series A5 Manual 16 July 2014 Page 33 of 40 Quartzlock Model E8 1PPS Series Operation Manual software should be started when in state 2 DO NOT allow the state to reach S4 and then commence the OCXO calibration This cannot be done when an external 1PPS source is being driven from the E8 1PPS board
51. y the performance measures The software will go through its start up procedure with the display of successive states ending in state 4 After 30 minutes the performance figures should be typically 1 2000E 08 1 2017E 08 0000000 00000 00001 5 8970E 13 5 8973E 13 Note that the Kalman phase estimate is almost identical to the time tag the mean square measurement error is zero the filtered performance indicator is zero the S1 multiplier is 1 the last frequency estimate and the mean frequency estimate is small This last figure will further reduce with time If the user 1PPS offset is stepped 10ns the effect on the performance parameters may be seen A single phase step will be rapidly tracked out with minimum effect on the frequency After this test reset the 1PPS base to the Kalman estimate by using the command OSP02 followed by EU E8 1PPS Series A5 Manual 16 July 2014 Page 39 of 40 Quartzlock Model E8 1PPS Series Operation Manual Quartzlock UK Ltd Web www quartzlock com E mail sales quartzlock com E8 1PPS Series A5 Manual 16 July 2014 Page 40 of 40
52. y time a 1PPS pulse is present If the red lock LED should start to flash at about 1Hz rate this indicates that the phase error between the GPS signal and the internal 20MHz oscillator is greater than a pre programmed threshold This does not indicate that the 1OMHz output is unlocked During normal operation the GPS receiver estimates the accuracy of the timing solution using the TRAIM algorithm Time Receiver Autonomous Integrity Monitoring If the predicted timing error is greater than the programmed limit the receiver will switch into holdover and the red lock LED will turn on The 10MHz output and 1PPS output will then drift according to the ambient temperature and aging of the internal oscillator The unit should never go into holdover during normal operation The most likely reason for doing so is a major antenna fault E8 1PPS Series A5 Manual 16 July 2014 Page 6 of 40 Quartzlock Model E8 1PPS Series Operation Manual GPS interface The GPS receiver interface uses NMEA format In order to use this a freeware program such as Trimble Studio should be installed on the user s PC Connect the unit to the PC and start the program It may be necessary to set the port and baud rate 9600 The various windows available from the program should show current satellite data etc GPS interface E8 X NavSync Version Only The Internal GPS receiver interface uses Motorola binary format In order to use this a freeware program such
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