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User Manual - EndRun Technologies

1. Command Summary Detailed Command Descriptions EMUL ees meee errr errr rere rere 00 505 ere 00 00 o 00 0 0 i 0 00 on 00 0 0 0 0 04 17 PROMIS SA one dc Caro RL mta Rs t Moe usd house cao coe ER AL eL REACQUIRE oo dete Gr o E Er v se e eee dr to 22 RESPMODEs x Secr acr at A Le AE Se A Se esce tel T Lc CEA ar DD VER eee eee mme 25 Praecis Il User Manual Clock Emulation Moes Dex yey wg E be ER Meat eM eot Ara AE LD 29 Tr eTimg 5 5 e a se ne e eie X re 29 Trimble as sara re rem hne o IIR Sepe RITE MR TR Pere Doer dne os 29 Chapter Five Setup with NTP 3l ONCE oou ere esae ee e RN odas Ren Eo E n N eC eu MS 3l Bosch IP SelUpi ne dida uade Ranieri dett n Ped s 33 Set the Symbolic Link i e Re RR ER hm RE e ER KET ARE a eg 34 Configure NTP 5 RSS ec tae rhe tosta eee t ese e slave e ortas o Sa de 34 Palisade NIP Setup 4 coa eda eoa a Ce e ENSE RN RON S buta e ns 35 Set ihe Symbolic Link erp 8 e ERR E RE ERR EIER RR RR RR HR S 37 Configure NTP 151 DEP CER EUER e ECT RR
2. 53 NUEGACY Command fe te Ve Stats Ta a cance M etr T 54 Appendix D Specifications 55 Special Modifications Changes for Customer Requirements 59 Praecis Il User Manual EndRun CT A TECHNOLOGIES Main Features ChapterOne Introduction The Praecis II is a precision source of Universal Coordinated Time UTC and Frequency that uses CDMA cell phone signals as its time synchronization source For more information that is not in cluded in this manual please visit our website http www endruntechnologies com There you can also download firmware upgrades the latest manuals and other documentation The Praecis II is the second generation of EndRun Praecis product line The Praecis II combines the features of the Praecis Ct and Praecis Cf and is backwards compatible with those first generation products while offering improved capabilities such as the ability to operate with PCS and Japanese CDMA signals See Appendix C for detailed information on differences between the old and new Praecis ASCII Time Of Day Message The Praecis II provides an ASCII time of day message via the RS 232 serial port The transmission of the first character in the message is on time with the beginning of each second and is accurate to within one millisecond There are several different message formats to choose from some are compatible with exis
3. 5 Praecis Il User Manual CHAPTER THREE 26 Praecis II User Manual EndRun C VAN Fr TECHNOLOGIES EndRun Format Chapter our Time Of Day Messages This chapter describes the format of the native Praecis II time message called the EndRun format plus the various formats used in emulating TrueTime and Trimble time messages TIME The EndRun format is used for showing time of day information when using the TIME command or for the continuous once per second output when EMUL NONE and CTIME ON See Chapter 3 Control and Status Commands for information on TIME EMUL and CTIME This format is described below T YYYY DDD HH DD SS zZZ m CC FF lt CR gt lt LF gt T is the Time Figure Of Merit TFOM character And is one of 9 indicates error gt 10 milliseconds or unsynchronized condition 8 indicates error 10 milliseconds 7 indicates error lt 1 millisecond 6 indicates error 100 microseconds YYYY is the year DDD is the day of the year HH is the hour of the day MM is the minute of the hour SS is the second of the minute zz is the time zone or local offset in units of half hours and is non zero only when the time mode is LOCAL or LOCALMAN m is the Time Mode character and is one of G GPS L LOCAL or LOCALMAN U UTC CC is the current leap seconds FF is the future leap seconds If a leap second is pending this value will match the current leap seconds value until it is within
4. After establishing communications with the Praecis II using the desired port settings issue the fol lowing command to initiate the upload upload lt CR gt lt LF gt After issuing this command you will see the Praecis II respond with this message Waiting for download using XMODEM 1K with CRC Control X will abort download CCC 47 Praecis Il User Manual Problems With The Upgrade Upgrade Using Linux and Minicom APPENDIX B You will then see the Praecis II send the character C every three seconds while it is waiting for you to begin uploading the image file Should you need to abort the upload process now send CTRL X to the Praecis II If you abort at this time your current firmware will remain intact If you abort after the file transfer is in progress you will not retain your original firmware You will need to re upload it Otherwise start the upload using the appropriate method for your terminal program During the upload your terminal program will display some sort of status indication If the upload is successful you will see the Praecis II reboot displaying the firmware version information when it does Note the firmware version information at this time and verify that it is indeed the firmware that you intended to upload If it is you have successfully upgraded the firmware in your Praecis II Should you have difficulties with the upgrade due to a corrupt file power failure during upload or other acciden
5. To test serial communications with the Praecis II you will need a terminal program You must con figure your terminal program to use the serial I O port you used above You must also configure your terminal program to use the correct baud rate number of data bits parity type and number of stop bits Turn off any handshaking The factory default settings for the Praecis II are 8 Praecis Il User Manual BASIC INSTALLATION Q 9600 is the Baud Rate Q 8 is the Number of Data Bits Q None is the Parity Q 1 is the Number of Stop Bits RECOMMENDED TERMINAL SETUP Use ANSI terminal emulation mode and turn OFF handshaking After configuring these parameters in your terminal program apply power to the Praecis II Within a few seconds your terminal program should display a sequence of boot messages similar to these Praecis II Bootloader 6010 0062 000 v 1 00 Jun 23 2010 13 09 04 Praecis II FW 6010 0063 000 v 1 00 Jun 25 2010 10 46 22 Praecis II FPGA 6020 0008 000 v 01 The first line gives the part number and version of the Praecis II bootloader firmware and the date and time of its compilation The second line gives the part number and version of the Praecis II ap plication firmware and the date and time of its compilation The third line gives the part number and version of the Field Programmable Gate Array FPGA configuration Following these three lines factory default operation is to send a time of day message once per second
6. 0 00 OSCTYPE This command allows you to query the oscillator type for this unit This value is set at the factory and cannot be changed because it depends on the hardware configuration of your Praecis II Query OSCTYPE lt CR gt lt LF gt Praecis II response TCXO lt CR gt lt LF gt PORT This command allows you to query and set the current serial I O port settings Changes to the set tings take place immediately and are retained in non volatile FLASH memory You must change your terminal program to match these settings in order to continue to communicate with the Praecis II Restoring the factory default settings may be necessary should you forget the current settings See Chapter 6 Indicator Mode Button and LEDs for details on restoring the factory default set tings The baud rate number of data bits parity and number of stop bits may be set Baud rate may be 9600 19200 38400 57600 Number of data bits may be 7 or 8 Parity may be E even O odd or N none Number of stop bits may be 1 or 2 Query PORT CR LF Praecis II response 9600 8 N 1 lt CR gt lt LF gt Set PORT 19200 7 0 2 lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting 9600 8 N 1 PPSWIDTH This command allows you to query and set the current IPPS output pulsewidth Set value is retained in non volatile FLASH memory The value is in units of milliseconds and may be 1 to 999 or NTP The NTP setting causes t
7. LEAP lt CR gt lt LF gt Praecis II response 0 O lt CR gt lt LF gt Set LEAP 15 15 Praecis II response OK Factory Default Setting Current and future leap seconds as of the date your Praecis II ships from the factory Since the Praecis II is shipped from the factory with the proper leap second information you need take no action with this command until the next leap second transition They occur about every 2 3 years Refer to the webpage above for information on the next leap second Once you modify this setting it will stay that way regardless of whether you reset factory defaults us ing the Indicator Mode Button see Chapter 6 Indicator Mode Button and LEDs To force the Praecis II to automatically receive leap second information from the CDMA base station set LEAP 0 0 This is not recommended but may be useful for some applications LO This command allows the you to set or query the local offset setting This setting is used to compute Local Time if TMoDE LOCALMAN see TMODE command The values entered can range from 12 30 to 12 30 Positive values indicate a time zone east of Greenwich Mean Time The minutes field must be either 00 or 30 Set value is retained in non volatile FLASH memory 20 Praecis II User Manual CONTROL amp STATUS COMMANDS Query LO lt CR gt lt LF gt Praeecis II response 7 00 lt CR gt lt LF gt Set LO 2412 30 cr 1f Praecis II response OK lt CR gt lt LF gt Factory Default Setting
8. The factory default continuous once per second time of day message format in the native Praecis II format EndRun format See Chapter 4 Time of Day Messages for a description of this message Initially you will see that the first character in the message the TFOM character is a 9 When the green LED begins to flash at the 1 Hz rate you should see the character change to a 6 which means that the time 1s accurate to less than 100 microseconds and the frequency is phase locked If you do not see characters displayed by your terminal program when the unit is powered up you must troubleshoot your setup An incorrectly wired cable is the most common problem Refer to Ap pendix D Specifications for the Praecis II RS 232 signal connections It is NOT necessary to use a null modem cable or adapter with the Praecis II If you are unable to find any errors in your setup as a last resort you should restore the factory default settings to the Praecis II It is possible that its serial port parameters are incorrect so restoring the factory default settings will correct that Refer to Chapter 6 Indicator Mode Button for the proce dure to restore the factory default settings 9 Praecis II User Manual Connecting Instruments to the Praecis Il CHAPTER TWO Once you have successfully established communications with the Praecis II you may procede to in stalling and configuring the software you intend to use to synchronize yo
9. refer to the LEAP command LOCAL The LOCAL setting will cause the time of day to be displayed with the local time zone offset to UTC The local time zone offset and daylight savings time transition is determined auto matically from data contained in the CDMA signal LOCALMAN The LOCALMAN setting will cause the time of day to be displayed with the lo cal time zone offset to UTC The local time zone offset is determined manually via the user interface refer to the LO DSTSTART and DSTSTOP commands Query TMODE lt CR gt lt LF gt Praecis II response GPS lt CR gt lt LF gt Set TMODE LOCAL lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting UTC 24 Praecis Il User Manual CONTROL amp STATUS COMMANDS UPLOAD This command allows you to upload a new program to the FLASH memory of the Praecis II Refer to Appendix B Upgrading the Firmware for detailed instructions for performing the UPLOAD proce dure Command UPLOAD lt CR gt lt LF gt Praecis II response Waiting for download using XMODEM 1K with CRC lt CR gt lt LF gt Control X will abort download lt CR gt lt LF gt CCCC The C character is sent until the terminal program begins the upload VER This query only command displays the firmware and hardware versions Query VER lt CR gt lt LF gt Praecis II response Praecis II FW 6010 0063 000 v 1 00 Jun 25 2010 10 46 22 FPGA 6020 0008 000 v 01 lt CR gt lt LF gt
10. which will match that of the Praecis Cf However besides the response to the vER command there are two othe small differences that remain The unit will respond instantly to a CHANNELSET command and there are two new fault bits in re sponse to the FLTSTAT command See details in the Praecis II and Praecis Cf Differences section above Praecis Ct Mode Configuration The Praecis II version information may cause problems for some equipment that has been developed to work with the Praecis Ct The Praecis Ct Mode will solve this problem by responding to the VER command as closely as possible to the way the Praecis Ct did This should be sufficient to maintain interoperability between the Praecis II configured as Praecis Ct Mode and other equipment Version information VER command for Praecis II configured as Praecis Ct Mode Praecis Ct FW 6010 0063 000 v 1 00 Jun 25 2010 16 41 39 Praecis FPGA 6020 0008 000 v 01 lt CR gt lt LF gt In addition the EndRun time of day message will NOT have leap seconds appended to it which will match that of the Praecis Ct Also the pulse width of the 1PPS Output on DCD will be set according to the baud rate of the serial port which will match the IPPS pulse width of the Praecis Ct There fore the PPSWIDTH command is not available for the Praecis Ct Mode However besides the response to the vER command there are two othe small differences that remain The unit will respond instantly to a CHANNELSET co
11. As of this writing kernel version 3 2 2 does not natively contain the timepps h file You have performed any kernel modifications and recompilations that may be needed to support 1PPS driven DCD operation on your platform If you are on the Linux platform kernel versions 2 6 38 and higher now have PPS support as a compile option for the standard kernel available from www kernel org Under Linux you will also need the dattach utility It must be a recent enough version to support the PPS line discipline Type 1dattach with no command line arguments to see a list of supported line disciplines You have performed Basic NTP Setup as described previously in this Chapter Basic NTP Setup is required because operation of the NTP with 1PPS driven DCD input measure ments is always in conjunction with one of the standard NTP reference clock drivers such as the Tru eTime driver NTP needs the time of day message from the NTP reference clock driver to determine the correct second for the rising edge of the next 1PPS Since the Praecis II supports a user selectable IPPS pulsewidth see Chapter 3 Control and Status Commands you should set it to the NTP value when you are using it for 1PPS driven DCD opera tion with NTP by issuing this command ppswidth ntp lt CR gt lt LF gt In this mode the 1PPS driven DCD pulsewidth will be set to the width of one bit at the selected baud rate of the serial I O port as required by the NTP referenc
12. EndRun Technologies shall not be liable for any direct indirect special incidental or consequential damages whether based on contract tort or any other legal theory EndRun Contact Information Address EndRun Technologies 2270 Northpoint Parkway Santa Rosa California 95407 U S A Phone 707 573 8633 Fax 707 573 8619 Sales 1 877 749 3878 or 707 573 8633 sales endruntechnologies com Support 1 877 749 3878 or 707 573 8633 support endruntechnologies com Praecis Il User Manual Praecis Il User Manual Table of Contents Pretite oss tr a e ues Sa Mot PE Sout o ou cisci depu ird i About EndRun Technologies Du a pote de oi abad e e ab ade ela ute i Trademark Acknowledgements i About This Manual se canso dra e EN Cx Ree adds ii Warranty E acy ak eat A RA eae css A RT ii Limitation of Warranty piece ey oo c ee Sae tee OR EE EN hats ade I E ii Warranty REPOR Yu tuac EE ed viaa Yes veda eco iii Repair After Warranty Expiration iii Limitation of Liability s t ace RO RC RU EPOR DDR E TRA AR iii EndRun Contact Information eee Sa Goatees iii Chapter One Introduction 1 Main Features cas ein cas tn srta ra E E e ap odd uude ASCII Time Of Day Message IPPS and 10MHz Outputs Dee Sob os a caesa be an ie uia Event Timetagding s
13. Hz rate Pulses Rapidly As the unit locks onto the CDMA signal and begins to decode the timing data the green LED will flash very rapidly about a 6 Hz rate until the data 1s fully decoded Pulses at When the unit is completely locked to UTC the green LED will One Pulse Per Second pulse at precisely a 1 Hz rate synchronized to UTC seconds with a short on duration relative to the off duration In Normal Indicator Mode the red LED is only illuminated briefly during the power up sequence and thereafter whenever any fault condition exists The nature of the fault may be determined by using the FLTSTAT serial I O command Signal Quality Indicator Mode Green LED FUNCTION The LED is off until CDMA signal is detected On The LED is on continuously once a CDMA signal has been detected Pulses Once the Praecis II begins to lock to the CDMA signal the green LED pulses on and off at a rate that is proportional to the received signal carrier to noise ratio A faster pulse rate means the signal is stronger This can be helpful in finding good loca tions for permanently mounting the Praecis II In Signal Quality Indicator Mode the red LED 1s turned on to indicate that either no Sync Channel data is available or that a Cyclical Redundancy Check CRC failure has occurred in decoding the Sync Channel data from the CDMA signal In general poor carrier to noise ratios as indicated by a slowly flashing green LED will result in a higher
14. RR RUN ERES 37 IRES NTPSIUD asas af OS ate a em are te T 38 Configure NTP 45 gsr see aere Ru e aa ele Ai len hed sir a ates 38 Chapter Six Indicator Mode Button and LEDs 4 Restoring Factory Default Settings 41 Indicator Mode Selection 114 4 c eser E or cba ta eem ei erc Re de M de 41 Appendix A Time Figure of Merit TFOM 45 Normal Indicator Mode 42 Signal Quality Indicator Mode 42 Appendix B Upgrading the Firmware 47 What You Need To Perform The Upgrade 47 Performing The Upgrade 226i ode emo E OUI EQ eta d vx OO HS TUNE RES 4 Problems With The Upgrade 48 Upgrade Using Linux and Minicom 48 Praecis Il User Manual Appendix C Backwards Compatibility 49 Praecis Il and Praecis Cf Differences 49 Praecis Il and Praecis Ct Differences 50 Legacy Product Configurations 52 Praecis Cf Mode Configuration 53 Praeds Ct Mode Configuration
15. The falling edge of the DCD output from the Praecis II is on time and the negative pulse width is set to one bit width at the selected baud rate Clear To Send CTS The Praecis II timetags with 32 nanosecond resolution the rising edge of transitions received on the CTS input For higher precision applications the Trimble Palisade NTP reference clock driver is a way around the IPPS complexity and is recommended if you find that 1PPS operation is too difficult to setup on your platform This reference clock driver asserts a Request To Send RTS on the computer s serial I O port which is connected via the supplied cable to the CTS input of the Praecis II serial I O port When configured for Trimble Palisade emulation mode the Praecis II timetags the rising edge of this CTS signal formats the timetag and returns it in a binary message that is compatible with the refer ence clock driver Trimble s web site contains extensive documentation concerning the use of the Trimble Palisade with NTP Much of this subject matter is also helpful in using the Praecis II when it is operating in Trimble Palisade emulation mode http www trimble com oem ntp Three methods of using the Praecis II with NTP on Unix like platforms will be described in increasing order of precision Basic This is the simplest and will yield a server whose timing accuracy is on the order of a few milliseconds It does not use the IPPS driven DCD output or CTS input event timeta
16. Then type this command lsz Xk binfile dev ttyS gt dev ttyS 2 gt amp 1 where binfile is the name of the file to upload and ttyS is the communication port you are using 48 Praecis Il User Manual EndRun C ANN Fr TECHNOLOGIES Praecis Il and Praecis Cf Differences AppendixC Backwards Compatibility The Praecis II is a second generation in a product series First generation products were the Prae cis Ct and the Praecis Cf The Praecis II replaces both the Praecis Ct and Praecis Cf This appendix is for those customers who were previous users of these older models and want to know exactly what the differences are For those customers who cannot tolerate any change in the operation of the Praecis because they have a software interface written specifically for the older models there is a special configuration of the Praecis II that will mimic as closely as possible the Praecis Ct or the Praecis Cf These special configurations are described at the end of this appendix North American PCS The major difference between the Praecis II and the Praecis Cf is that the Praecis II can synchronize to both North American CDMA cellular frequencies 800 MHz and PCS frequencies 1900 MHz The Praecis Cf would only use the cellular frequencies Adding the capability to use the North American PCS frequencies is a big benefit as the Praecis will now operate in some areas where it previously could not The channelset command has been c
17. at power up and thereafter whenever a serious fault condition exists In Signal Quality Mode it indicates the failure rate for decoding timing information from the CDMA signal The Indicator Mode Button 1s used for toggling between the LED Normal Mode and LED Signal Quality Mode or for restoring factory default settings This SMA jack connector provides a 1 PPS signal capable of driving 50 ohms at TTL levels This SMA jack connector provides a 10 MHz squarewave signal capable of driving 50 ohms at TTL levels This RJ 45 connector provides the RS 232 transmit and receive signals as well as the two special timing signals needed to operate with the NTP reference clock drivers see Chapter 5 Setup with NTP This 3 5 mm phone jack connector provides power Praecis Il User Manual Performing an Initial Site Survey BASIC INSTALLATION This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruc tion manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be re
18. communicate with the Praecis II and know which serial I O device on your host computer you are using You have installed NTP version 4 on your host computer and the Truetime reference clock driver is compiled into the ntp daemon To complete the setup these general steps will be performed The example which follows gives the detailed step by step instructions 1 Issue the command to the Praecis II to set it to emulate the TrueTime clock type Then make sure that the Praecis II serial I O port parameters are compatible with the TrueTime NTP reference clock driver Refer to Chapter 3 Control and Status Commands for detailed information on using the serial I O port with the Praecis II 2 Next create a symbolic link in your dev directory which points to the serial I O port to which your Praecis II is connected The symbolic link must be called true0 when you are using the Tru eTime NTP reference clock driver 3 Finally edit the ntp conf file so that NTP will use the TrueTime NTP reference clock driver EXAMPLE The following example will set up NTP on a Linux system First stop the power up default con tinuous once per second time of day message output by sending this command from your terminal program to the Praecis II ctime off lt CR gt lt LF gt The Praecis II will respond OK lt CR gt lt LF gt Now send this command to change the time of day message format to TrueTime emulation emul truetime lt CR gt lt LF gt
19. does not have these fields as shown below T YYYY DDD HH DD SS zZZ m For detailed information on each field in the time of day messages and the other message formats available see Chapter 4 Time Of Day Messages 51 Praecis II User Manual Legacy Product Configurations APPENDIX C Changing Channelset In the Praecis Ct if the unit is locked when you enter the cHANNELSET command then you also need to enter a REACQUIRE command in order to force the unit to start searching for a new CDMA signal See Chapter 3 Control and Status Commands for details on CHANNELSET and REACQUIRE In the Praecis II even if the unit is locked it will automatically start searching for a new CDMA signal as soon as you enter the CHANNELSET command Additional Favlt Indicators Two new fault indicators have been added to the FLTSTAT command response These are the Time Input Fault and the Main Osc Failure See FL TSTAT in Chapter 3 Control and Status Commands for details Version Information In response to the vER command the Praecis sends firmware and FPGA version information This message is slightly different between the Praecis II and the Praecis Ct See Chapter 3 Control and Status Commands for a description of this command Praecis II version information Praecis II FW 6010 0063 000 v 1 00 Jun 25 2010 16 41 39 FPGA 6020 0008 000 v 01 lt CR gt lt LF gt Praecis Ct version information Praecis Ct FW 6010 0001 000 v 1 00 Sep 18
20. driver which you have just configured You should verify that is is being reached You may have to continue issuing the peers command for a minute or two before you will see the reach count increment If you have other peers configured verify that the offset information for the Tru eTime peer and your other peers is in agreement to within a few milliseconds assuming that the other peers are synchronized to that level of accuracy It may also be useful to start the NTP daemon in debug mode ntpd d to confirm successful con figuration Refer to the NTP documentation for detailed usage of these debug utilities Setup using the Trimble Palisade emulation mode is not much more complicated than basic setup if You have been able to successfully communicate with the Praecis II and know which serial I O device on your host computer you are using You have installed NTP version 4 on your host computer and the Trimble Palisade reference clock driver is compiled into the ntp daemon To complete the setup these general steps will be performed The example which follows gives the detailed step by step instructions 1 Issue the command to the Praecis II to set it to emulate the Trimble Palisade clock type Then make sure that the Praecis II serial I O port parameters are compatible with the Trimble Palisade NTP reference clock driver Refer to Chapter 3 Control and Status Commands for detailed information on using the s
21. each rising edge of the CTS serial I O input sig nal The Event time message format is T YYYY DDD HH MM SS sssssssss zZZ m lt CR gt lt LF gt See the Chapter 4 Time Of Day Messages for details on the EndRun time message format Factory Default Setting OFF FLTMSG This query only command displays the current fault status of the Praecis II as one or more human friendly messages When operating in the Normal LED Mode see Chapter 6 Indicator Mode Button and LEDs then any fault condition will also illuminate the red LED For more detailed information on each fault see the fault descriptions in FLTSTAT below Query FLTMSG lt CR gt lt LF gt Praecis II response No faults or CDMA synchronization signal not found FLTSTAT This query only command displays the current fault status of the Praecis II The fault status is shown as contained in sixteen bits which are displayed in four hexadecimal characters Each bit of each hexadecimal character indicates the status of a Praecis II component When operating in the Normal Mode see Chapter 6 Indicator Mode Button and LEDs then any fault condition will also illumi nate the red LED FLASH Write FPGA Config No Signal DAC Control Fault Fault Time Out Over Range 1 Main Osc Time Input Fault Local Osc Failure Local Osc PLL Failure Fault DAC Control Over Range This bit indicates that the electronic frequency control DAC for the oscillator has reached either the high 55000 or
22. incidence of CRC failures as indicated by a larger ratio of red LED on time to off time 42 Praecis Il User Manual INDICATOR MODE BUTTON AND LEDs In general it is advisable to return the Praecis II to the Normal Indicator Mode when you have finished your site selection and installation Otherwise you may not be able to verify that your Praecis II is operat ing properly by simple observation of the red LED However when the Praecis II is being used in a frequency standard application it may be more important to know the CDMA locking status as you are performing measurements based upon the Praecis II output frequency This is due to the holdover characteristics of the TCXO which are not good enough for many precision applications In these situations it may be desirable to operate the Praecis II in the Signal Quality Mode which gives a real time indication of the CDMA signal tracking status 43 Praecis Il User Manual CHAPTER SIX 44 Praecis Il User Manual EndRun ANE EN TECHNOLOGIES Appendix Time Figure of Merit TFOM This appendix describes the Time Figure of Merit TFOM number The EndRun time of day mes sage sent by the Praecis II contains a character that indicates the level of accuracy that should be included in the interpretation of the time of day contained in the message This is called the TFOM and ranges from 6 to 9 time error is lt 100 microseconds time error is lt 1 milliseconds time error is lt 1
23. large ambient temperature swings may occur Equipment capable of meeting these requirements is at the current state of the art The CDMA time and frequency engine in the Praecis II receives the same initialization signals trans mitted by the base stations that are used by the mobile telephones to establish their synchronization to system time The mobile telephones cannot communicate in the system until they have established synchronization with the received spread spectrum encoded waveform Unlike the mobile tele phones once this synchronization has occurred the CDMA time and frequency engine in the Praecis II has all of the information that it needs to perform its function of delivering accurate UTC time to a network of computers The mobile telephone must decode much more information establish 2 Praecis Il User Manual Where to Use It INTRODUCTION two way communications with the base station and be a paid subscriber to performs its function of placing and receiving calls All of this means that during normal operation the quality of the timing information being trans mitted from each of the base stations is virtually a repeat of that directly obtainable from the GPS The big difference is that the received signal strengths from the base stations are a minimum of 30 dB larger than those from the GPS satellites which is why you can usually talk on your cell phone indoors Due to the nature of the IS 95 spread spectrum CDMA modulation s
24. low 10000 limit while locked to the CDMA sig 18 Praecis Il User Manual CONTROL amp STATUS COMMANDS nal Unless the unit is being subjected to out of specification environmental conditions this would indicate that the oscillator frequency has drifted near to the end of life region This should normally only occur after about ten years of operation The unit will continue to function until the oscillator frequency finally reaches one of the actual DAC endpoints The unit should be returned to the factory for oscillator replacement at the customer s convenience No Signal Time Out This bit indicates that the unit has not been able to acquire a CDMA signal for one hour while the Time Figure of Merit has been 9 see Appendix A TFOM This could be due to a variety of reasons If there are no other faults that could explain the inability to receive a signal then there could be a base station outage or antenna failure If the condition persists indefi nitely and a problem with the antenna is not evident the unit may need to be returned to the factory for repair FPGA Config Fault This bit indicates that the microprocessor was unable to configure the FPGA This would be a fatal fault and the unit should be returned to the factory for repair FLASH Write Fault This bit indicates that the microprocessor was unable to verify a write to the FLASH non volatile parameter storage area This should not occur under normal operation The unit shou
25. of synchronizing the base stations throughout the network so that neighboring cells do not interfere with each other and so that calls can be efficiently transferred between the base stations without inter ruption as the mobile user traverses the cell coverage areas This soft hand off feature means that the mobile telephone must be able to hitlessly drop one base station and pick up the next one To do this the telephone must be able to calculate the relative difference in time between the codes that modulate the signals from each of the base stations which again requires that the base stations be synchronized The system designers chose the Global Positioning System GPS which is itself a CDMA based system as the means of maintaining synchronization and they defined system time to be GPS time Each base station throughout the system contains one or more high performance GPS timing receiv ers with sophisticated algorithms that control either an extremely stable ovenized quartz crystal oscil lator or a Rubidium vapor atomic frequency standard Such elaborate means are needed to meet the very difficult operating specifications required by the TIA EIA IS 95 standard The base station time synchronization must remain within 10 microseconds of GPS time over periods as long as twenty four hours during which GPS satellite signals might not be available typically due to antenna cable failure damage or vandalism and in an environment where
26. shell command where x is the serial device number to which your Praecis II is connected ln s dev ttySx dev true0 Configure NTP Now you must edit the ntp conf file which ntpd the NTP daemon looks for by default in the the etc directory Add these two lines to the ntp conf file server 127 127 5 0 prefer fudge 127 127 5 0 refid CDMA The first line tells ntpd to use the TrueTime reference clock driver and to prefer it over all other serv ers which might be declared in the ntp conf file The trailing zero in the server address is the unit id and in this case tells ntpd to use the device pointed to by the symbolic link true0 The second line tells ntpd to replace the default reference identification field for the TrueTime reference clock driver with the characters CDMA This reference identification field is transmitted in the NTP server reply 34 Praecis Il User Manual Palisade NTP Setup SETUP WITH NTP packets that are sent in response to NTP client request packets It identifies the source of your NTP server s reference time Re start ntpd to have it begin using the Praecis II as the preferred synchronization peer Use the NTP utility ntpq to check that ntpd is able to communicate with the Praecis II After issuing the command ntpq you will see the ntpq command prompt ntpq gt Use the command peers to display the NTP peers which your computer is using One of them should be the TrueTime refer ence clock
27. the EMUL command 8 Not Connected S lt 56 Praecis II User Manual SPECIFICATIONS DCD 1 Pulse Per Second Output Characteristics Signal RS 232 levels falling edge is on time Accuracy Same as the IPPS Timing Accuracy above CTS Input Event Timetagging Characteristics Signal RS 232 levels Rising edge can be captured with 32 nanosecond resolution Accuracy Same as the IPPS Timing Accuracy above Resolution 32 nanoseconds Pulse Width 100 nanoseconds minimum Re Arm Delay 1 milliseconds i e the first event during any millisecond will be timetagged Buffering No events are buffered Events occurring at a rate higher than 10 Hz will be discarded due to system loading and serial I O transmission limitations Power Connector 3 5mm phone jack 6 VDC 400 mA Universal AC AC wall adapter is included Size Case 4 85 L x 2 68 W x 1 18 H Weight 1 2 pound 270 grams Helical Antenna 4 25 L x 0 40 diameter Mag Mount Antenna 2 diameter at base by 14 H Environmental Temperature 0 to 70 C Humidity 0 to 95 non condensing Compliance FCC Part 15 Subpart B Class A 57 Praecis Il User Manual APPENDIX D 58 Praecis Il User Manual EndRun CT R mw TECHNOLOGIES Special Modifications Changes for Customer Requirements From time to time EndRun Technologies will customize the standard Praecis II CDMA Timing Mod ule for special customer requirements If your unit has been modified then this se
28. to be set For example in the United States the DST start date is the second Sunday in March at 2 00 a m To set this the command would be DSTSTART 4 1 2 You may disable DST by setting either the DSTSTART or DSTSTOP parameters to 0 For example DSTSTART 0 0 0 Month is 1 12 Sunday is 1 4 for 1 2 39 4 or L for last Hour is 0 23 where O is midnight Query DSTSTART lt CR gt lt LF gt Praecis II response 4 1 2 lt CR gt lt LF gt 16 Praecis II User Manual CONTROL amp STATUS COMMANDS Set DSTSTART 4 1 2 lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting 0 0 0 DSTSTOP This command allows you to query and set the stop time for the Daylight Savings Time transition This setting is used to compute Local Time if TMoDE LOCALMAN see TMODE command Set value is retained in non volatile FLASH memory Syntax for the command is psTSTOP m s h The month of the year the Sunday of the month and the hour of the transition all need to be set For example in the United States the DST stop date is the first Sunday in November at 2 00 a m To set this the command would be pststop 10 L 2 You may disable DST by setting either the DSTSTART or DSTSTOP parameters to 0 For example DsTSTOP 0 0 0 Month is 1 12 Sunday is 1 4 for 1 2 3 4 or L for last Hour is 0 23 where O is midnight Query DSTSTOP lt CR gt lt LF gt Praecis II response 10 L 2 lt CR gt lt LF gt Set DSTSTOP 10 L 2 C
29. 0 milliseconds time error is gt 10 milliseconds unsynchronized state if never locked to CDMA I ON In all cases the Praecis II reports this value as accurately as possible even during periods of CDMA signal outage where the Praecis II is unable to directly measure the relationship of its timing outputs to UTC During these CDMA outage periods assuming that the Praecis II had been synchronized prior to the outage the Praecis II extrapolates the expected drift of the its timing signals based on its knowledge of the characteristics of the internal Temperature Compensated Crystal Oscillator TCXO The extrapolated TFOM is based on a conservative estimate of the performance of the TCXO and should be considered worst case for a typical benign ambient temperature environment Due to this extrapolation behavior brief removal of the antenna from a normally operating Praecis II II will not induce an immediate alarm condition If the antenna is removed for long enough periods you should see the TFOM character change to indicate a gradually deteriorating accuracy of the timing outputs If the signal loss condition persists longer then the final unsynchronized state will eventually be reached If the Praecis II is unable to achieve re synchronization within one hour after reaching this state the red LED will illuminate Queries using the FLTSTAT or FLTMSG commands see Chapter 4 Control and Status Commands will indicate a loss of signal t
30. 10 milliseconds 7 indicates error lt 1 millisecond 6 indicates error lt 100 microseconds is the year is the day of the year is the hour of the day is the minute of the hour is the second of the minute is the sub seconds information is the time zone or local offset in units of half hours and is non zero only when the time mode is LOCAL or LOCALMAN is the Time Mode character and is one of G GPS L LOCAL or LOCALMAN U UTC is the current leap seconds is the future leap seconds If a leap second is pending this value will match the current leap seconds value until it is within 24 hours of the transition Within 24 hours of a leap second transition it will show the actual future leap seconds value lt CR gt lt LF gt is an ASCII carriage return CTRL M 0x0D and line feed CTRL J 0x0A 28 Praecis Il User Manual Clock Emulation Modes TIME OF DAY MESSAGES The following formats are used only for the continuous once per second time of day output Use the EMUL command to select the various formats If EMUL NONE then the EndRun format will be used see above Use the CTIME command to turn the continuous time output ON or OFF TrueTime This format is sent once each second with the CR being the on time character which is sent during the first millisecond of each second The Time Mode is always UTC in this emulation mode SOH DDD HH MM SSQ lt CR gt lt LF gt lt SOH gt is the ASCII S
31. 2007 16 41 39 FPGA 6020 0001 000 v 01 lt CR gt lt LF gt Additional Commands The following commands are new and did not exist in the Praecis Ct FL TMSG PPSWIDTH and com mand specific HELP See Chapter 3 Control and Status Commands for more information on these new commands The Praecis Ct and the Praecis Cf have been produced for many years As such over the years there has been developed equipment by other manufacturers intended to interface with these older prod ucts In order to avoid disrupting this relationship the Praecis II may be configured to mimic as closely as possible these older legacy products 52 Praecis II User Manual BACKWARDS COMPATIBILITY Praecis Cf Mode Configuration Not too many differences exist between the Praecis II and the Praecis Cf However the version in formation may cause problems for some equipment that has been developed to work specifically with the Praecis Cf The Praecis Cf Mode will solve this problem by responding to the VER command as closely as possible to the way the Praecis Cf did This should be sufficient to maintain interoperabil Ity between the Praecis II configured as Praecis Cf Mode and other equipment Version information VER command for Praecis II configured as Praecis Cf Mode Praecis Cf FW 6010 0063 000 v 1 00 Jun 25 2010 10 46 22 Praecis FPGA 6020 0008 000 v 01 lt CR gt lt LF gt In addition the EndRun time of day message will NOT have leap seconds appended to it
32. 24 hours of the transition Within 24 hours of a leap second transition it will show the actual future leap seconds value lt CR gt lt LF gt is an ASCII carriage return CTRL M 0x0D and line feed CTRL J 0x0A When this message is received in response to the TIME command it will show the exact time at the point when the Praecis II receives TIME lt CR gt lt LF gt When this message is received in the continuous once per second time of day output the T at the beginning of the message is the on time character This means that this character is transmitted at the beginning of each second within 1 millisecond of the second roll over 27 Praecis Il User Manual CHAPTER FOUR EVENT This version of the EndRun format is used for showing time of day information when using the event input capability This time of day message shows the exact time of the receipt of an when an event signal occurs See Chapter 3 Control and Status Commands for information on the EVENT com mand See Appendix D Specifications for details on the event input signal The only difference between this and the previous EndRun format is the addition of sub seconds information T YYYY DDD HH DD SS sssssssss ZZZ m CC FF lt CR gt lt LF gt YYYY DDD HH MM SS SSSSSSSSS zz CC FF is the Time Figure Of Merit TFOM character And is one of 9 indicates error gt 10 milliseconds or unsynchronized condition 8 indicates error lt
33. EndRun c man 2 7ECHNOLOGIES Smarter Timing Solutions Preecis II CDMA Timing Module User Manual Pr cis II CDMA Timing Module User Manual Preface Thank you for purchasing the Praecis II Our goal in developing this product is to bring precise Universal Coordinated Time UTC and Frequency to your system quickly easily and reliably Your new Praecis II is fabricated using the highest quality materials and manufacturing processes available today and will give you years of trouble free service About EndRun Technologies EndRun Technologies is dedicated to the development and refinement of the technologies required to fulfill the demanding needs of the time and frequency community The instruments produced by EndRun Technologies have been selected as the timing reference for a variety of industries and applications computer networks satellite earth stations power utilities test ranges broadcast and telecommunications systems and more EndRun Technologies is committed to fulfilling your precision timing needs by providing the most advanced reliable and cost effective time and frequency equipment available in the market today Trademark Acknowledgements UNIX and Trimble Palisade are registered trademarks of the respective holders Part No USM3002 0000 000 Revision 5 April 2013 Copyright EndRun Technologies 2010 2013 Praecis Il User Manual About This Manual This manual will guide you through simple installa
34. LF gt Set RESPMODE TERSE lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting TERSE SETTINGS This query only command displays the current status of all of the user configurable settings These settings are held in non volatile FLASH memory 22 Praecis Il User Manual CONTROL amp STATUS COMMANDS Query SETTINGS CR LF Praecis II response Cal 0 000000000 lt CR gt lt LF gt Channelset NORTH AMERICA CELLULAR lt CR gt lt LF gt Ctime OFF lt CR gt lt LF gt DSTStart 0 0 0 lt CR gt lt LF gt DSTStop 0 0 0 lt CR gt lt LF gt Emul NONE lt CR gt lt LF gt Event OFF lt CR gt lt LF gt Leap 15 15 lt CR gt lt LF gt Lo 0 00 lt CR gt lt LF gt Port 57600 8 N 1 lt CR gt lt LF gt PPSwidth 1 lt CR gt lt LF gt Respmode TERSE lt CR gt lt LF gt Tmode UTC lt CR gt lt LF gt SPSTAT This query only command displays the current status of selected signal processor parameters This is a fixed length message formatted as shown SPS CHAN PNO AGC VCDAC SNR FERR lt CR gt lt LF gt Where SPS is the Signal Processor State one of ACQ Acquiring DET Signal Detected LKG Code Locking TKG Carrier Locking LKD Locked CHAN is the CDMA frequency channel being used For North American frequencies the reported channel will be PRIA PRIB SECA or SECB These stand for Primary A Primary B Secondary A or Secondary B channels For Korean frequencies the reported ch
35. R LF Praecis II response OK lt CR gt lt LF gt Factory Default Setting 0 0 0 EMUL This command allows you to query and set the current clock emulation mode for the continuous once per second time of day message output There are four allowable emulation modes NONE TRIMBLE and TRUETIME Set value is retained in non volatile FLASH memory See Chapter 4 Time Of Day Messages for details Query EMUL lt CR gt lt LF gt Praecis II response NONE lt CR gt lt LF gt Set EMUL trimble lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting NONE EVENT This command allows you to query and set the status of the CTS input event timetagging The status may be set to either ON or OFF Set value is retained in non volatile FLASH memory When the clock emulation mode is set to TRIMBLE using the EMUL command the CTS input event timetag ging status is forced to ON TRIMBLE and any attempt to change this using the EVENT command will be ignored If CTIME is ON its output takes priority over these event timetags It is recommend 17 Praecis Il User Manual CHAPTER THREE ed that CTIME be turned OFF during event timetagging operation Refer to Appendix D Specifica tions for event input details Query EVENT lt CR gt lt LF gt Praecis II response OFF lt CR gt lt LF gt Set EVENT 0n lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Then an Event time message will be sent following
36. STSTART 0 0 0 will disable the Daylight Savings Time user override The time mode must be LOCALMAN in order for the Praecis II to use the DSTSTOP information See TMODE EMUL With no parameter x this command shows the emulation EMUL x mode for the continuous once per second time of day output see CTIME With a parameter this command sets the emulation mode where x may be NONE TRUETIME or TRIMBLE EVENT With no parameter x this command shows the current setting EVENT x for the event timetagging function With a parameter this command enables or disables the event timetagging function where x is ON or OFF FLTMSG This command shows the system fault status as human friendly messages FLTSTAT This command shows the system fault status as a machine EE l friendly hexadecimal code HELP With no parameter x this command shows a list of all avail HELP x able commands With a parameter this command will show help information specific to x where x is another command For example HELP FLTMSG will show help information specific to the FLT MSG command LEAP With no parameters this command shows the current setting for LEAP c f the user override leap second information With parameters this command will override the leap second information as transmitted by the CDMA base station and use the leap second information as entered where c is the current leap seconds fis the future leap seconds LEAP 0 0 will force the Pra
37. The Praecis II will respond OK lt CR gt lt LF gt Now you need to make sure that the serial I O port parameters of the Praecis II are compatible with those expected by the TrueTime NTP reference clock driver 9600 8 N 1 You can check the cur rent settings by sending port lt CR gt lt LF gt The Praecis II should respond 9600 8 N 1 lt CR gt lt LF gt If the PORT command responds with different settings then you must change them using PORT com mand with the appropriate arguments 33 Praecis II User Manual CHAPTER FIVE port 9600 8 n 1 lt CR gt lt LF gt If you had to change the port settings you will now need to change the settings in your terminal program to match the new ones in order to be able to continue communicating with the Praecis II Now turn the time of day message output back on ctime on lt CR gt lt LF gt You should now see a time of day message in the TrueTime emulation format issued once per sec ond lt SOH gt DDD HH MM SSQ lt CR gt lt LF gt The Praecis II is now configured for operation with the True Time NTP reference clock driver Shut down your terminal program now so that it does not interfere with the NTP reference clock driver later Set the Symbolic Link Now you must define a symbolic link in your dev directory that points to the serial I O port to which the Praecis II is connected The name of this link is used by the NTP reference clock driver For Linux you might issue this
38. accuracy due to increase propagation delay Stability TDEV lt 50 ns t lt 104 seconds Connector SMA bulkhead jack 10 MHz Frequency Characteristics Signal Positive TTL pulse 500 Accuracy 10 to UTC for E hour averaging times when locked Stability o 1 10 for v 10 seconds oy 1 lt 10 C for t gt 10 seconds Connector SMA bulkhead jack I O Signals DCD Output at RS 232 levels See DCD 1 Pulse Per Second Output Characteristics below CTS Input at RS 232 levels See CTS Input Event Timetagging Characteristics below Serial I O RXD TXD at RS 232 levels User selectable parameters 9600 19200 38400 57600 baud 7 or 8 data bits odd even or no parity 1 or 2 stop bits Connectors RJ 45 Connector RJ 45 to DB9F adapter cable assembly included RJ 45 Pin DBOF Pin Signal Name on Praecis II on Adapter 1 1 Data Carrier Detect DCD DCD is driven by the 1PPS signal from the Praecis II Falling edge is on time 2 2 Transmit Data TXD H H NI Receive Data RXD RXD is driven by the host computer E E comes 000007 Ground GND GND is connected to the power supply ground on the Praecis II 6 6 Not Connected S 7 7 Clear To Send CTS CTS is driven by Request To Send RTS from the host computer The Praecis II timetags the rising edge of CTS when the Event timetagging function is ON see the EVENT command or if the Praecis II 1s operating in Trimble Palisade emulation mode see
39. al interface that allows for 100 microsecond synchro nization or better for critical computer time synchronization applications using the Network Time Praecis Il User Manual CDMA Timing How It Works CHAPTER ONE Protocol NTP These signals are a IPPS output on the RS 232 Data Carrier Detect DCD and an event input on the RS 232 Clear To Send CTS which is described above See Chapter 5 Setup With NTP for how to use these signals with NTP See Appendix D Specifications for RS 232 serial port specifications and details on the event input and the IPPS output Easy Installation Its small size and integrated antenna make installation a snap compared to competing direct GPS products Once the unit is placed near the instrument or computer requiring synchronization con nected the needed signals and plug in the AC adapter See Chapter 2 Basic Installation Free FLASH Upgrades Firmware 15 stored in non volatile FLASH memory so the Praecis II can be easily upgraded in the field using the local RS 232 port We make all firmware upgrades for our products available to our customers free of charge See Appendix B Upgrading the Firmware for more information The CDMA time and frequency engine in the Praecis II receives transmissions from base stations also known as cell sites that are operating in compliance with the TIA EIA IS 95 standard for Code Division Multiple Access CDMA mobile telecommunications This system requires a means
40. ameter this command will set the respmode of the Praecis II where x is TERSE or VERBOSE SETTINGS Shows a list of all user setable commands and their current settings SPSTAT Shows current status and information for the CDMA signal processor TIME Shows the current time in the EndRun time message format See Chapter 4 Time of Day Messages 14 Praecis Il User Manual Detailed Command Descriptions CONTROL amp STATUS COMMANDS TMODE With no parameter x this command shows the current time TMODE x mode used for calculating time With a parameter this command will set the time mode where xis GPS UTC LOCAL or LOCALMAN The time mode setting affects time information shown in the EndRun format only Other formats are shown in UTC time mode only See Chapter 4 Time Of Day Messages UPLOAD Forces the Praecis II to begin the FLASH upload process Shows the Praecis II firmware and FPGA versions CAL This command allows you to query and set the value of a calibration offset that the Praecis II can make to the Praecis II timing outputs It can be useful for compensating various delays present in a system The units for the offset are seconds The allowable range is 0005 seconds to 4 0005 sec onds where a positive calibration offset means that the Praecis II timing outputs will be advanced in time The Praecis II performs this adjustment with a resolution of approximately 32 5 nanoseconds The example response indicate
41. annel will be PRKA PRKB SEKA or SEKB These stand for Primary A Primary B Secondary A or Secondary B chan nels For Indian frequencies the reported channel will be 1851 2261 2671 3081 3691 4101 4511 or 492 There are multiple primary and secondary channels in the Indian channelset so the channel number is being used PNO is the base station PseudoNoise Offset O to 511 in units of 64 PseudoNoise code chips AGC Is the Automatic Gain Control DAC byte 0 to 255 with larger numbers implying higher RF gain Typical range is 150 to 220 VCDAC isthe TCXO Voltage Control DAC word 0 to 65535 with larger numbers implying higher TCXO frequency Typical range is 20000 to 38000 SN R is the carrier Signal to Noise Ratio 0 00 to 99 9 measured in the Sync Channel symbol rate bandwidth Typical range is 2 5 to 11 0 F ERR is the Sync Channel Frame Error Rate 0 000 to 1 000 with a higher number imply ing more Cyclical Redundancy Check failures when processing the Sync Channel message frames Higher numbers will correlate with lower Signal to Noise Ratios 23 Praecis II User Manual CHAPTER THREE Query SPSTAT lt CR gt lt LF gt Praecis II response LKD PRIB 132 161 28495 6 9 0 000 lt CR gt lt LF gt TIME This query only command displays the current time of day in the EndRun format See Chapter 4 Time Of Day Messages for details about this format The example response shows the local time and indicates a local offset to UTC o
42. asine rs Y N ec Dm Foe e nr wee Sue RR ee TER Ea RS 232 Signals For Use With NTP asas prods pum EEE tay es Qe C gu pa Easy Installation aoc oo arara sa a bU YE ee RU e en aia der A od ae 2 Free FLASH Upgrades 5i oe RR CEDE eR RECS S SUE reese ede AR SEE ne 2 CDMA Timing How It Works 2 Where to Use a e Des a nta ee DX Rea anre AR eam ib ada 3 Chapter Two Basic Installation 5 Checking and Identifying the Hardware 5 Praecis Il Physical Description 6 Performing an Initial Site Survey 2 544 ua nana X CU se 7 Connecting Computers to the Praecis Il 8 Mountithe Praecis 1L ost e cepas Tom eme eee Ret e ae eR Wea ale deeds 8 Conned the Serial Port s uo ette IE ete da N EA EEE E E EE R 8 Test the Serial Port 2 2 34 4e ses sieno RE AERE EEE AE eR e Re 8 Connecting Instruments to the Praecis Il 10 Praecis Il User Manual apter Three Control and Status Commands 11 11 i 12 15 D recie A da E tn dt L CHANNEDSET ote aces ae rane de La ecd pu eed ace Fes A date Lg General Serial 1 0 Operation
43. cheme this timing information may be extracted by a well designed receiver with a precision of a few nanoseconds The CDMA time and frequency engine in the Praecis II does just that and for this reason we call our technology indirect GPS First the Praecis II must be deployed in a cellular or PCS IS 95 CDMA coverage area Cellular is a commonly used term implying that the frequency band for the base station carrier transmissions is 824 895 MHz This is in contrast to PCS which implies operation in the 1850 1990 MHz frequency band If available the Praecis II uses the cellular frequency band because it provides much better propagation characteristics in regards to building penetration and maximum receivable range from the transmitter In regions lacking cellular coverage the unit can be set to receive the PCS signals In general if your CDMA telephone works where you plan to install the Praecis II then your Praecis II will work properly there 3 Praecis Il User Manual CHAPTER ONE 4 Praecis Il User Manual EndRun C VAN Fr TECHNOLOGIES Checking and Identifying the Hardware Chapter Two Basic Installation This chapter will guide you through the most basic checkout and physical installation of your Praecis II Subsequent chapters and appendices will give you the information needed to configure your in stallation for the maximum performance in your operating environment Unpack and check all the items using the shipment
44. ction will describe what those changes are This section is blank 59 Praecis Il User Manual SPECIAL MODIFICATIONS 60 Pr eris II User Manual EndRun TECHNOLOGIES Smarter Timing Solutions 2270 Northpoint Parkway Santa Rosa CA 95407 TEL 1 877 749 3878 FAX 707 573 8619 www endruntechnologies com
45. d be the TrueTime refer ence clock driver which you have just configured You should verify that it is being reached You may have to continue issuing the peers command for a minute or two before you will see the reach count increment You should also see the PPS refclock in the peer list If you have other peers con figured verify that the offset information for the TrueTime and PPS peers and your other peers is in agreement to within a few milliseconds assuming that the other peers are synchronized to that level of accuracy It may also be useful to start the NTP daemon in debug mode ntpd d to confirm successful configuration Refer to the NTP documentation for detailed usage of the debug utilities 39 Praecis Il User Manual CHAPTER FIVE 40 Praecis II User Manual EndRun C VAN Fr TECHNOLOGIES Restoring Factory Default Settings Indicator Mode Selection ChapterSix Indicator Mode Button and LEDs This chapter describes the Indicator Mode Button and its two functions One function is to restore factory default settings for all parameters The other function is to toggle between two operating modes for the LEDs called the Normal Indicator Mode and the Signal Quality Indicator Mode The Indicator Mode Button is located on the same end plate of the Praecis II where the antenna input jack and indicator LEDs are mounted It is accessed through a small hole in the endplate to the left of the LEDs A paper cl
46. dding a new parameter p to force the Prae cis to search PCS channels channelset p Additional Outputs There are two new outputs on the Praecis II that did not exist in the Praecis Ct These are a 1 Pulse Per Second 1PPS and 10 MHz both on SMA connectors Specifications are shown in Appendix D Specifications Pulse Width The factory default setting for the IPPS signal is one millisecond wide in the Praecis II In the Prae cis Ct the 1PPS pulse width was dependent upon the baud rate of the serial port The 1 PPS signal is output on the RS 232 Data Carrier Detect DCD line and the new SMA connector To change the IPPS pulse width to match that of the old Praecis Ct simply use the PULSEWIDTH command as PPSWIDTH NTP This setting will be saved in non volatile memory so you will not need to do this again unless you reset factory default settings using the Indicator Mode Button as described in Chapter 6 Time of Day Message The EndRun time of day message has been changed to add leap seconds information This is the message format for the response to the TIME command is used for event timetagging see EVENT and is one of the selections for the continuous once per second output see CTIME Refer to Chap ter 3 Control and Status Commands for a description of these commands Praecis II time of day message T YYYY DDD HH DD SS zZZ m CC FF The last fields CC and FF are the current and future leap seconds The Praecis Ct
47. e clock drivers On Linux platforms you must load the PPS kernel modules modprobe pps core pps ldisc and you must start the dattach daemon ldattach PPS dev trueO To complete the setup it only remains to edit the ntp conf file so that NTP will use the 1PPS kernel measurements Configure NTP Having performed the setup steps in Basic NTP Setup now you must edit the ntp conf file which ntpd the NTP daemon looks for by default in the etc directory Find the two lines which you added previously in Basic NTP Setup and insert these lines immediately after them 38 Praecis Il User Manual SETUP WITH NTP server 127 127 22 0 minpoll 4 maxpoll 4 fudge 127 127 22 0 flag2 1 flag3 1 These lines tell ntpd to use timetags that the kernel captures on the positive transitions of the DCD line of the serial I O port pointed to by dev true0 It will associate these IPPS measurements with the reference clock driver which has the prefer keyword In this example that would be the Tru eTime reference clock driver that was setup in Basic NTP Setup Restart ntpd to have it begin using the Praecis II as the preferred synchronization peer with 1PPS measurement capability enabled Use the NTP utility ntpq to check that ntpd is able to communicate with the Praecis II After issuing the command ntpq you will see the ntpq command prompt ntpq gt Use the command peers to display the NTP peers which your computer is using One of them shoul
48. e following manner Code 1 Static 1 Sat Timing Mode is set when the time error is lt 1 ms Code 2 Approximate Time is set when the time error is lt 10 ms Code 3 Startup is set when the time error is gt 10 ms 29 Praecis Il User Manual CHAPTER FOUR Do Praecis H User Manual EndRun C VAN Fr TECHNOLOGIES Overview Chapter ive Setup with NTP This chapter describes the basic procedure for setting up the Praecis II to work with various Network Time Protocol NTP reference clock drivers on Unix like platforms To configure your Unix like computer to use your Praecis II you must have successfully completed the installation procedures in Chapter 2 Basic Installation This manual is not a How To on in stalling and using NTP Basic approaches to NTP configuration for operation with the Praecis II will be described It is expected that you are or have access to a capable Unix Linux system administra tor and know more than a little about installing distributions from source code and re compiling your kernel Installation must be performed by a user with root priviledges on the system If you have never used NTP then you should spend some time reading the on line documents especially the Dis tribution Notes FAQ and Reference Clock Driver subject matter which are available at http www ntp org Many problems may also be solved by the helpful people who participate in the Internet news group devoted to NTP n
49. e sure the RMA number is clearly identified on the shipping container Our policy is to repair the unit within 5 business days If it is necessary to order parts or if other circumstances arise that require more than 5 days an EndRun service technician will contact you Loaner units are not included as part of the standard warranty Repair After Warranty Expiration If the warranty period has expired we offer repair services for equipment you have purchased from EndRun Call and ask for a customer service agent It is important to contact us first as many prob lems may be resolved with a phone call Please have the serial number of the unit and the nature of the problem available before you call Ifitis determined that the equipment has failed and you want EndRun to perform the repairs we will issue you an RMA number Ship the unit prepaid in the original container or a container of sufficient strength and protection to EndRun Technologies EndRun will not be responsible for damage incurred during shipping to us Customer is responsible for shipping costs to and from EndRun Technologies Be sure the RMA number is clearly identified on the shipping container After the equipment has been received we will evaluate the nature of the problem and contact you with the cost to repair parts and labor and an estimate of the time neces sary to complete the work Limitation of Liability The remedies provided herein are Buyer s sole and exclusive remedies
50. e unit will light the red LED for about ten seconds 2 Then it will continuously light the green LED 3 When the unit has detected a CDMA signal the green LED will begin to flash very slowly about a 4 Hz rate 4 As the unit locks onto the CDMA signal and begins to decode the timing data the green LED will flash very rapidly about a 6 Hz rate until the data 1s fully decoded 5 Then the green LED will pulse at precisely a 1 Hz rate synchronized to UTC seconds with a short on duration relative to the off duration 7 Praecis Il User Manual Connecting Computers to the Praecis Il CHAPTER TWO At this point the unit is fully synchronized and you may procede to permanently mounting it in the desired location If this sequence has not occurred within twenty minutes you should move the unit and or change its orientation and re try If you are unable to find a location where the unit will acquire the CDMA sig nals you may not have cellular coverage in your area or the signal might be too weak in your facility The Praecis II is shipped from the factory to search for CDMA signals in the cellular frequency band You can use the channelset command see Chapter 3 Control and Status Commands to force the Praecis II to search for CDMA signals in the PCS frequency band If you are still unable to re ceive signals you should continue trying for at least a day since CDMA base stations are taken down for service from time to time If
51. ecis II to use the leap second info as transmitted by the CDMA base station 13 Praecis II User Manual CHAPTER THREE With no parameter x this command shows the current local offset setting With parameters this command will override the local offset information as transmitted by the CDMA base station and use the local offset info as entered where x is a value from 12 30 to 12 30 and is for time zones east of Greenwich Mean Time The seconds field must be either 0 or 30 The time mode must be LOCALMAN in order for the Praecis II to use the LO information See TMODE OSCTYPE Shows the installed oscillator type PORT With no parameters this command shows the current serial port PORT b d p s settings With parameters this command will set the serial port settings where bis baud rate 9600 19200 38400 57600 dis data bits 7or8 pis parity o e or n for odd even or none s is stop bits 1 or 2 PPSWIDTH With no parameter x this command shows the current setting PPSWIDTH x for the pulse width of the IPPS Output With a parameter this command sets the pulse width for the IPPS Output where x is 1 to 999 for 1 to 999 milliseconds or NTP REACQUIRE Forces the Praecis II to start over in its search fora CDMA synchronization signal RESET This command will reset the unit RESPMODE With no parameter x this command will show the current set RESPMODE x ting for the response mode With a par
52. erial I O port with the Praecis II 35 Praecis II User Manual CHAPTER FIVE 2 Now create a symbolic link in your dev directory which points to the serial I O port that your Praecis II is connected to The symbolic link should be called palisade0 3 Now edit the ntp conf file so that NTP will use the Trimble Palisade NTP reference clock driver EXAMPLE The following example will set up NTP on a Linux system First stop the power up default con tinuous once per second time of day message output by sending this command from your terminal program to the Praecis II ctime off lt CR gt lt LF gt The Praecis II will respond OK lt CR gt lt LF gt Now send this command to change the time of day message format to Trimble Palisade emulation emul trimble lt CR gt lt LF gt The Praecis II will respond OK lt CR gt lt LF gt Now you need to make sure that the serial I O port parameters of the Praecis II are compatible with the Trimble Palisade NTP reference clock driver 9600 8 O 1 by sending port lt CR gt lt LF gt The Praecis II should respond 9600 8 0 1 lt CR gt lt LF gt If the port command responds with different settings then you must change them using the port command port 9600 8 0 1 lt CR gt lt LF gt The Praecis II is now configured for operation with the Trimble Palisade NTP reference clock driver Shut down your terminal program now so that it does not interfere with the NTP reference clock driver late
53. etained in non volatile FLASH memory PCS Korean and Indian users will need to change the default setting as below Query CHANNELSET lt CR gt lt LF gt Praecis II response NORTH AMERICA lt CR gt lt LF gt Set CHANNELSET P lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting NORTH AMERICA This is the setting as shipped by the factory but will not be affected by resetting factory defaults using the Indicator Mode Button see Chapter 6 Indicator Mode Button and LEDs Once you modify this setting it will stay that way CTIME This command allows you to query and set the status of the continuous once per second time of day message output The status is either ON or OFF Set value is retained in non volatile FLASH memory Query CTIME lt CR gt lt LF gt Praecis II response Off CR LF Set CTIME on lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Then the continuous once per second time of day output message starts in the format previously selected using the EMUL command Factory Default Setting ON DSTSTART This command allows you to query and set the start time for the Daylight Savings Time transition This setting is used to compute Local Time if TMoDE LOC ALM AN see TMODE command Set value is retained in non volatile FLASH memory Syntax for the command is DSTSTART m s h The month of the year the Sunday of the month and the hour of the transition all need
54. ews your_news_server comp protocols time ntp All instructions given here assume that you are using NTP Version 4 Version 4 is required for operation using the Trimble Palisade emulation capabilities of the Praecis Il If you are planning to use the 1PPS ca pabilities of the Praecis II upgrading to NTP Version 4 is also recommended In NTP Version 4 an attempt has been made to reduce some of the platform dependency in using the 1PPS measurements You should determine which features are available for your platform that pertain to specific NTP reference clock drivers In particular use of the 1PPS input timetagging capabilities of the NTP is somewhat messy and very platform dependent Some platforms support the 1PPS input timetagging capability natively others require additional code and a kernel re compile You must determine what you need for your platform If you only need a few milliseconds of precision then all platforms will support synchronization us ing the standard NTP reference clock drivers which merely timetag the receipt of a specific on time 31 Praecis Il User Manual CHAPTER FIVE character in the clock s time of day message This is the easiest path to setting up an NTP server and is recommended for all but the most demanding applications This mode of operation does not make use of the two special signals on the Praecis II serial I O connector Data Carrier Detect DCD The Praecis II drives this signal from its IPPS output
55. f 11 5 hours meaning that local time is 11 5 hours ahead of UTC So for this example UTC time of day would be 02 15 01 The leap seconds fields show that 15 leap seconds is the value for both current and future leap seconds This means there is no leap second pending Query TIME lt CR gt lt LF gt Praecis II response 6 2000 155 13 45 01 23 L 15 15 lt CR gt lt LF gt TMODE This command allows the user to query and set the current clock time mode Set value is retained in non volatile FLASH memory The setting of the time mode has no effect on the continuous once per second time of day messages sent when emulating the Trimble or TrueTime clock types They are always sent in UTC time The time mode setting affects the time of day messages that are in the EndRun format only There are four available time modes GPS The GPS setting will cause the time of day to be displayed without the leap seconds which have been inserted between the UTC and GPS timescales since the beginning of GPS time January 6 1980 At the time of this writing 15 leap seconds have been applied to UTC since the GPS epoch so GPS time is currently 15 seconds ahead of UTC time UTC The UTC setting will cause the time of day to be displayed as UTC time UTC time is GPS time with the addition of leap seconds Leap seconds can be determined by the unit automati cally from data contained in the CDMA signal Leap seconds can also be determined manually via the user interface
56. gging capabilities of the Praecis II It does not require special modifications to the kernel and you should be able to use a pre compiled NTP distribution if one is available for your platform NTP beginners and 1PPS users should always perform this setup first Palisade This method is simpler than the IPPS driven DCD method and uses the CTS input event timetagging capability of the Praecis II The precision attainable is comparable to the IPPS driven DCD output method and is under 100 microseconds Since this NTP reference clock driver is fairly new your NTP distribution may not include it If not you should download an up to date NTP dis tribution and install it Recommended for most users due to the relatively simple set up and high precision attainable IPPS This is more complicated and will yield a server with precision less than 100 microsec onds It uses the IPPS driven DCD output capability of the Praecis II You will have to do more in depth research and study to understand the interworking between the NTP and the Unix like kernel It may require Unix Linux kernel modifications to support its operation You may have to re compile NTP to take advantage of any kernel modifications you made to support IPPS Recommended only for experienced NTP users who are unable to use the Trimble Palisade driver 32 Praecis Il User Manual Basic NTP Setup SETUP WITH NTP Basic setup is relatively simple if You have been able to successfully
57. hanged slightly by adding a new parameter p to force the Prae cis to search PCS channels channelset p Time of Day Message The EndRun time of day message format has been changed to add leap seconds information This is the message format for the response to the TIME command is used for event timetagging see EVENT and is one of the selections for the continuous once per second output see CTIME Refer to Chapter 3 Control and Status Commands for a description of these commands Praecis II time of day message T YYYY DDD HH DD SS zZZ m CC FF The last fields CC and FF are the current and future leap seconds The Praecis Cf does not have these fields as shown below T YYYY DDD HH DD SS zZZ m For detailed information on each field in the time of day messages and the other message formats available see Chapter 4 Time Of Day Messages 49 Praecis Il User Manual Praecis Il and Praecis Ct Differences APPENDIX C Changing Channelset In the Praecis Cf if the unit is locked when you enter the CHANNELSET command then you also need to enter a REACQUIRE command in order to force the unit to start searching for a new CDMA signal See Chapter 3 Control and Status Commands for details on CHANNELSET and REACQUIRE In the Praecis II even if the unit is locked it will automatically start searching for a new CDMA signal as soon as you enter the CHANNELSET command Additional Favlt Indicators Two new fault indicators ha
58. he 1PPS pulsewidth to be automatically set to one bit width at the currently selected baud rate of the serial I O port This is for use with the IPPS on DCD NTP reference clock drivers See Chapter 5 Setup with NTP for more information on PPSWIDTH NTP Query PPSWIDTH lt CR gt lt LF gt Praecis II response 1 lt CR gt lt LF gt 21 Praecis Il User Manual CHAPTER THREE Set PPSWIDTH 500 CR LF Praecis II response OK lt CR gt lt LF gt Factory Default Setting REACQUIRE With this command you can force the CDMA receiver to start over in its search for a valid CDMA signal This is generally only used for debugging Command REACQUIRE lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt RESET This command allows you to perform a software reset of the unit Command RESET lt CR gt lt LF gt Praecis II response OK RESPMODE This command allows you to query and set the current serial I O command response mode Set value is retained in non volatile FLASH memory In the factory default TERSE mode all responses to que ry commands are as described in this Chapter When the response mode is set to VERBOSE a string consisting of the command name a space character the equals sign character and a space character 1s prepended to the TERSE response string for all query commands except HELP and sETTINGS Query RESPMODE lt CR gt lt LF gt Praecis II response RESPMODE VERBOSE lt CR gt lt LF gt or TERSE lt CR gt lt
59. ill be stored in FLASH and remain configured as a Praecis Cf until you specifically change it using the LEGACY command Praecis Il User Manual EndRun DS EN TECHNOLOGIES AppendixD Specifications CDMA Receiver Cellular Mobile Receive Band 869 894 MHz Standard North American PCS Mobile Receive Band 1930 1990 MHz Standard Japanese Cellular Mobile Receive Band 860 875 MHz Optional Configuration TIA EIA IS 95 CDMA Pilot and Sync Channels Magnetic Mount Antenna SMA plug Zin 50 ohms Dual Band 824 896 MHz 1850 1990 MHz Magnetic base monopole with integral 12 ft RG 58 U cable and SMA plug Extension cables and low noise pre amplifiers are available as options Helical Antenna SMA plug Zin 50 ohms Dual Band 824 896 MHz 1850 1990 MHz Local Oscillator TCXO is standard 2 5x10 over 20 to 70 C Option OCXO 4x10 over 0 to 70 C Time to Lock 5 minutes typical TCXO 10 minutes typical OCXO Indicators Lock LED Green LED pulses to indicate CDMA acquisition and lock status Alarm LED Red LED indicates a fault condition Indicator Mode Button Dual Functions restores factory defaults and selects LED mode Normal or Signal Quality 5B Praecis I User Manual APPENDIX D Pulse Per Second 1PPS Timing Characteristics Signal Positive TTL pulse 500 Accuracy 10 microseconds to UTC typical when locked Fringe area reception may degrade the absolute timing
60. ime out condition 45 Praecis Il User Manual APPENDIX A 46 Praecis II User Manual What You Need To Perform The Upgrade Performing The Upgrade EndRun ANNE EN TECHNOLOGIES Appendix Upgrading the Firmware Periodically EndRun Technologies will make bug fixes and enhancements to our products available for download from our website All such downloads are freely available to our customers without charge After you have downloaded the appropriate FLASH binary image file you are ready to per form the upgrade to your Praecis II You will need a terminal program which supports file uploading using the XMODEM 1K protocol with CRC This is a very common file transfer protocol and should be supported by virtually any terminal program You may perform the upload using any of the supported serial 1 0 parameter combinations except that 8 data bits must be used You must use 8 data bits because the FLASH image you vill be uploading to the Praecis Il is in a binary format Using the higher baud rates will reduce the time needed to transfer the image file to the Praecis II The current image requires about one minute to transfer when using a baud rate of 57600 Configure your terminal program and the Praecis II to communicate at the desired baud rate by using the settings facility for your terminal program and the port command for the Praecis II Refer to Chapter 3 Control and Status Commands for details on using the port command
61. ip or other small diameter blunt tool is a good way to gently depress the button Do not use an excessive amount of force in depressing the Indicator Mode Button Damage to the switch and or its connection to the printed circuit board could result from such excessive pressure Should you wish to reset the Praecis II to its factory default settings follow this procedure Press and hold in the Indicator Mode Button for at least five seconds The Praecis II will acknowl edge the factory default restoration by flashing both of the LEDs together three times All command settings are now reset to factory default settings See Chapter 3 Control and Status Commands for the factory default setting for each command Some command settings CHANNEL SET and LEAP are not affected by resetting factory defaults After power has been applied pressing the Indicator Mode Button will toggle the Indicator Mode between the Normal and Signal Quality modes of operation On power up the Praecis II is always in the Normal Indicator Mode which means that the current synchronization status 1s indicated using the green LED as described in Chapter 2 Basic Installation Performing a Site Survey 41 Praecis Il User Manual CHAPTER SIX Normal Indicator Mode Green LED FUNCTION On The green LED is on continuously until a CDMA signal is detected Pulses Slowly When the unit has detected a CDMA signal the green LED will begin to flash very slowly about a 4
62. l set where x may be A for North America Cellular K for North America Korea Cellular I for India or P for North America PCS For Japanese units the channel set cannot be altered and will always show CHANNELSET J for Japan Cellular With no parameter x this command shows the status of the continuous once per second output With a parameter this command enables or disables the con tinuous output where x may be ON or OFF With no parameters this command shows the current settings for the Daylight Savings Time DST user override With parameters this command will override the DST informa tion as transmitted by the CDMA base station and use the DST info as entered where m is month of DST start point s is Sunday of the month of DST start point h is hour of the transition of DST start point DSTSTART 0 0 0 will disable the Daylight Savings Time user override The time mode must be LOCALMAN in order for the Praecis II to use the DSTSTART information See TMODE Praecis Il User Manual CONTROL amp STATUS COMMANDS DSTSTOP With no parameters this command shows the current settings DSTSTOP m s h for the Daylight Savings Time DST user override With parameters this command will override the DST informa tion as transmitted by the CDMA base station and use the DST info as entered where m is month of DST stop point s is Sunday of the month of DST stop point h is hour of the transition of DST stop point D
63. ld be returned to the factory for repair Local Oscillator PLL Fault This bit indicates that the local oscillator phase locked loop PLL synthesizer is unlocked This condition should not normally occur unless the unit is subjected to out of specification environmental conditions Otherwise this would be a fatal fault and the unit should be returned to the factory for repair Local Oscillator Failure This bit indicates that the local oscillator phase locked loop PLL synthesizer has failed This condition should not normally occur unless the unit is subjected to out of specification environmental conditions Otherwise this would be a fatal fault and the unit should be returned to the factory for repair Time Input Fault This bit indicates that the microprocessor received an erroneous time input from the CDMA engine If the condition persists please report it to the factory Main Oscillator Failure This bit indicates that the main oscillator has failed This condition should not normally occur unless the unit is subjected to out of specification environmental condi tions Otherwise this would be a fatal fault and the unit should be returned to the factory for repair The example response indicates that there has been a period without tracking a CDMA signal that exceeded the time out period that there was a FLASH Write Fault and that there is a Local Oscillator PLL fault Query FLTSTAT lt CR gt lt LF gt Praecis II response 0x001A l
64. manufacturer from date of shipment Limitation of Warranty The foregoing express warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer or User Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site prepa ration or maintenance TO THE EXTENT PERMITTED BY LAW THIS WARRANTY AND REMEMDIES SET FORTH ABOVE ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES REMEDIES AND CONDITIONS WHETHER ORAL OR WRITTEN STATUTORY EXPRESS OR IMPLIED AS PERMITTED BY APPLICABLE LAW ENDRUN SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE Praecis Il User Manual Warranty Repair If you believe your equipment is in need of repair call EndRun Technologies and ask for a customer service agent It is important to contact us first as many problems may be resolved with a phone call Please have the serial number of the unit and the nature of the problem available before you call If it is determined that your equipment will require service we will issue an RMA number You will be asked for contact information including your name address phone number and e mail address Ship the unit prepaid in the original container or a container of sufficient strength and protection to EndRun Technologies EndRun will not be responsible for damage incurred during shipping to us B
65. mmand and there are two new fault bits in re sponse to the FLTSTAT command See details in the Praecis II and Praecis Ct Differences section above 53 Praecis II User Manual APPENDIX C LEGACY Command This is a special command intended only for those who require changing the configuration of the Praecis II to one of the legacy product configurations Praecis Cf or Praecis Ct Once this has been changed it will not be affected by resetting factory defaults see Chapter 6 Indicator Mode Button When you change the LEGACY setting the unit will automatically reset factory defaults You will need to type a RESET command to restart the unit and properly set up hardware for your new configu ration LEGACY 1s not shown in the Praecis II HELP menu nor as part of the response to the SETTINGS command Syntax is LEGACY x where x is 1 for Praecis II 2 for Praecis Cf Mode and 3 for Prae cis Ct Mode Query Praecis II response Query Praecis II response Set Praecis II response 54 LEGACY CR LF LEGACY 1 Praecis II Unless specified at time of order all Praecis II are shipped with this configuration HELP LEGACY lt CR gt lt LF gt Information related to the LEGACY command is displayed LEGACY 2 CR LF OK The unit will automatically reset factory defaults to those of Praecis Cf Mode You will need to type a RESET command in order to properly set up the hardware The new LEGACY setting w
66. ntpq command prompt ntpq gt Use the command peers to display the NTP peers which your computer is using One of them should be the Trimble Palisade reference clock driver which you have just configured You should verify that is is being reached You may have to continue issuing the peers command for a minute or two before you will see the reach count increment If you have other peers configured verify that the offset information for the Palisade peer and your other peers is in agreement to within a few milliseconds assuming that the other peers are synchronized to that level of accuracy It may also be useful to start the NTP daemon in debug mode ntpd d to confirm successful con figuration Refer to the NTP documentation for detailed usage of the debug utilities 37 Praecis Il User Manual IPPS NTP Setup CHAPTER FIVE You are ready to setup using the 1PPS driven DCD capability of the Praecis II if You have been able to successfully communicate with the Praecis II and know which serial I O device on your host computer you are using You have installed an up to date NTP version 4 on your host computer and the Truetime reference clock driver is compiled into the NTP daemon You must also have the Atom reference clock driver compiled into the daemon For Linux you must have the PPS related header include files present on your system in order to compile the NTP daemon with the Atom reference clock driver
67. packing list Contact the factory if anything is missing or damaged The Praecis II shipment typically contains where x variable number Praecis II part 3002 x00x 00x Praecis II User Manual part USM3002 0000 000 on CD part 5102 0001 000 Praecis II Antenna Kit part 0610 0011 000 consisting of Helical antenna part 0502 0015 000 Magnetic mount antenna cable assembly part 0502 0007 000 Praecis II Accessory Kit part 0648 0010 000 consisting of AC to 6VDC Universal AC Power Supply part 0623 0002 000 RJ 45 to RJ 45 CAT 5 patch cable 2 meters part 0501 0000 000 RJ 45 to DB9F adapter part 0501 0001 000 2 Self adhesive velcro dots part 0100 0055 000 and 0100 0055 001 5 Praecis II User Manual CHAPTER TWO Praecis Il Physical Description Antenna Sync Alarm Indicator Input Status Status Mode Jack LED LED Button Sa S EndRun TECHNOLOGIES ln Preecis II NE T3 10 MHz Power Serial 1 PPS Output Input VO Output Jack Jack Jack Jack Antenna Jack Lock LED Alarm LED Indicator Mode Button PPS Output Jack 10 MPPS Output Jack RS 232 Jack Power Input Jack This SMA jack connector mates with either one of the supplied antennas In Normal Mode this green LED flashes to indicate the synchronization status In Signal Quality Mode it flashes to indicate the received signal quality In Normal Mode this red LED illuminates briefly
68. quired to correc the interference at his own expense Using the status LED indicators it s easy to find out if your Praecis II will work in your desired loca tion 1 Screw the magnetic mount antenna cable onto the SMA antenna jack of the Praecis II Two differ ent antennas are shipped with the Praecis II Try the magnetic mount antenna first as it 1s better able to receive weak signals Once you have the Praecis II working with this antenna then you may switch to the other antenna if you prefer 2 Plug the supplied AC to 6VDC power supply into a 115 VAC outlet 3 Plug power input 3 5 mm phone plug into the 3 5 mm phone jack on the Praecis II Place the antenna on a flat preferably metallic surface while the unit is searching for a signal Make sure that it is not blocked by large metallic objects closer than one meter You may hold the Praecis II in your hand or place it next to the antenna Although the unit should normally be installed with the antenna oriented vertically usually multipath conditions due to signal reflections indoors cause at least some of the signal to be horizontally polarized so do not be surprised if you find that the unit will work either way Multipath conditions can also cause another effect signal cancellation Since the wavelength of the signal is only about thirty centimeters movement of the antenna just a few centimeters can sometimes cause significant signal strength changes Initially upon power up 1 Th
69. r am Praecis I User Manual SETUP WITH NTP Set the Symbolic Link Now you must define a symbolic link in your dev directory that points to the serial I O port to which the Praecis II is connected The name of this link is used by the NTP reference clock driver For Linux you might issue this shell command where x is the serial device number to which your Praecis II is connected ln s dev ttySx dev palisadeO Configure NTP Now you must edit the ntp conf file which ntpd the NTP daemon looks for by default in the the etc directory Add these lines to the ntp conf file server 127 127 29 0 prefer fudge 127 127 29 0 refid CDMA The first line tells ntpd to use the Palisade reference clock driver and to prefer it over all other serv ers The trailing zero in the server address is the unit id and in this case tells ntpd to use the device pointed to by the symbolic link palisade0 The second line tells ntpd to replace the default reference id field for the Palisade reference clock driver with the characters CDMA This reference id field is transmitted in the NTP server reply packets that are sent in response to NTP client request packets It identifies the source of your NTP server s reference time Re start ntpd to have it begin using the Praecis II as the preferred synchronization peer Use the NTP utility ntpq to check that ntpd is able to communicate with the Praecis II After issuing the command ntpq you will see the
70. s that are terminated with either an ASCII Carriage Return CTRL M 0x0A control character denoted by lt CR gt or an ASCII Carriage Return CTRL M 0x0A Line Feed CTRL J 0x0D pair of control characters denoted by lt CR gt lt LF gt The Praecis II terminates all status messages that it sends in response to commands with a lt CR gt lt LF gt pair The Praecis II does not echo any user input The Praecis II responds to invalid commands with ERROR lt CR gt lt LF gt or INVALID OPERATION lt CR gt lt LF gt At power up with factory default settings the Praecis II outputs a time of day message once per sec ond The factory default emulation mode is NONE and the Praecis II sends the time of day message in its native EndRun format See Chapter 4 Time Of Day Messages for details on the various clock emulation message formats RECOMMENDED TERMINAL SETUP Use ANSI terminal emulation mode and turn OFF handshaking 11 Praecis Il User Manval Command Summary CHAPTER THREE COMMAND FUNCTION CAL CAL x CHANNELSET CHANNELSET x CTIME CTIME x DSTSTART DSTSTART m s h With no parameter x this command shows the timing calibration factor With a parameter this command sets the timing calibration factor where x may be 0 0005 to 0005 and advances the timing outputs With no parameter x this command shows the selected CDMA receiver channel set With a parameter this command sets the channe
71. s that the outputs are currently retarded by 123 452 microseconds rela tive to UTC as received from the CDMA base station In urban areas distances to base stations should normally be less than two miles It could make sense to set the calibration offset to perhaps 5 microseconds half of the approximate light speed transit time over two miles to improve the absolute accuracy of the Praecis II If you have some way of knowing how far the closest base station is from your site you could make a more educated adjust ment using the approximate propagation delay of one nanosecond per foot or 3 3 nanoseconds per meter and the CAL command Set value is retained in non volatile FLASH memory Query CAL lt CR gt lt LF gt Praecis II response 000123452 lt CR gt lt LF gt Set CAL 00015 lt CR gt lt LF gt Praecis II response OK lt CR gt lt LF gt Factory Default Setting 0 Numerical inputs are accepted in any standard format for this command For example you may enter 1 5e 4 for the number 0 00015 CHANNELSET This command allows you to set the frequency channels that the CDMA receiver searches in order to find a timing signal Most users will not need to use this command as the default setting is for the North American Cellular frequency channel set There are four allowable entries A for North Amer 15 Praecis II User Manual CHAPTER THREE ica Cellular P for North America PCS K for Korea and I for India Cellular Set value is r
72. t do not be alarmed Even though you may have lost the existing application program the Praecis II bootloader program will remain intact On boot up it will check to see if a valid ap plication program is in the FLASH memory If there is not it will immediately go into the waiting for download mode sending the C character every three seconds You may then re try the upload procedure after you have corrected the original problem It is possible for the bootloader program to be fooled by a corrupted application program that has been previously downloaded into FLASH In this case it will attempt to start the application pro gram Generally this will result in a failure that will force a watchdog initiated reboot This process will be repeated indefinitely unless you intervene If the bootload application launch sequence appears to be caught in a loop type recover right after the bootloader version string is displayed This will cause the bootloader to ignore the presence of what it thinks is a valid application program in FLASH and to initiate the XMODEM upload se quence When you see the character C being displayed every three seconds you may initiate the upload of a new application program file Using minicom to perform the upgrade can be problematic Follow this procedure 1 Use minicom to talk to the unit Issue the upload command and wait for the c characters to start 2 Now exit from minicom with CTRL A Q
73. t CR gt lt LF gt HELP This query only command displays a menu of the available status and control commands supported by the Praecis II along with the syntax of their usage Command specific help is also available 19 Praecis Il User Manual CHAPTER THREE Query HELP lt CR gt lt LF gt Praecis II response Full menu of available commands is displayed Query HELP LEAP lt CR gt lt LF gt Praecis II response Information related to the LEAP command is displayed LEAP This command allows the user to set the current and future leap seconds Set value is retained in non volatile FLASH memory The CDMA mobile phone system does provide a mechanism for automatic UTC leap second insertion However there are some locations where this has not been implemented to the precision needed for a smooth leap second transition This command overrides the UTC leap second information received from the CDMA base station In so doing your Praecis II will properly perform a leap second transition at UTC midnight Leap seconds are inserted at UTC midnight on June 30 or December 31 only If there is no leap second pending at the next transition point then enter the command with current future If there is a leap second pending then enter the command with current future 1 The EndRun Technologies website maintains a page devoted to notifying users of the appropriate current and future leap second values at http www endruntechnologies com leap htm Query
74. tart of Header CTRL A 0x01 control character DDD is the day of year HH is the hour of the day MM is the minute of the hour SS is the second of the minute Q is the Time Quality character and may be one of the following indicates the unsynchronized condition indicates error lt 50 ms indicates error 5 ms indicates error lt 1 ms indicates error lt 1 ms space character lt CR gt lt LF gt is an ASCII carriage return CTRL M 0x0D and line feed CTRL J 0x0A Trimble This format is only useful in conjunction with the Trimble Palisade NTP reference clock driver as it is not human readable See Chapter 5 Setup with NTP for more information It is sent in Trimble Standard Interface Protocol TSIP using a binary packet format Primary NTP Pkt 8F AD The Event Timetag function is forced to ON TRIMBLE and any attempt to change this using the EVENT command will be ignored The Praecis II will send packets at every event occurrence on the RS 232 CTS assertion events and will also send once per second packets if CrIME ON It is recommended that CTIME OFF when using this emulation mode These packets contain a timestamp with 32 nanosecond resolution The time information in this message is always UTC regardless of what the time mode is see TMODE Byte 18 Receiver Status of NTP Pkt 8F AD contains the synchronization status information The Praecis II uses three of these codes and they are set in th
75. ting Network Time Protocol NTP reference clock drivers See Chapter 4 Time Of Day Messages for information on the various formats See Chapter 5 Setup With NTP for information on using the time of day messages with reference clock drivers See Appendix D Specifications for information on the RS 232 serial port signals IPPS and 10MHz Outputs The Praecis II provides a 1 PPS pulse per second and 10 MHz output via SMA connectors Instru mentation applications may use these signals to achieve time synchronization to typically less than 10 microseconds and frequency syntonization to less than one part in 10 See Chapter 2 Basic Installation Connecting Instruments to the Praecis II for more information See Appendix D Specifications for details on the IPPS and 10 MHz outputs Event Timetagging The Praecis II has an input available for timetagging events The rising edge of this signal can be captured with 32 nanosecond resolution and with 10 microseconds accuracy typical when the Praecis II is locked These events are not buffered and there is a limit to how fast they can be pro cessed These specifications are detailed in Appendix D Specifications The ASCII format for the time of day message is shown in Chapter 4 Time Of Day Messages Instructions for turning the event input capability on or off is in Chapter 3 Control amp Status Commands RS 232 Signals For Use With NTP The Praecis II has two special signals on the seri
76. tion and set up procedures Introduction The Praecis II how it works where to use it its main features Basic Installation How to connect configure and test your Praecis II Console Port Description of the console commands for use over the serial port If you detect any inaccuracies or omissions please inform us EndRun Technologies cannot be held responsible for any technical or typographical errors and reserves the right to make changes to the product and manuals without prior notice Warranty This product manufactured by EndRun Technologies is warranted against defects in material and workmanship for a period of one year from date of shipment under normal use and service During the warranty period EndRun Technologies will repair or replace products which prove to be defec tive For warranty service or repair this product must be returned to EndRun Technologies Buyer shall prepay shipping charges to send product to EndRun Technologies and EndRun Technologies shall pay shipping charges to return product to Buyer However if returned product proves to be operating normally not defective then Buyer shall pay for all shipping charges If Buyer is located outside the U S A then Buyer shall pay all duties and taxes if any Products not manufactured by EndRun Technologies but included as an integral part of a system e g peripherals options are warranted for ninety days or longer as provided by the original equipment
77. ur computer s clock to UTC The Praecis II provides two precision output signals capable of driving properly terminated coaxial cables IPPS and 10 MHz These two signals are DC coupled and sourced from Advanced CMOS ACMOS drivers which are able to maintain output TTL levels into a 50 ohm load They are ac cessed via the two SMA jacks on the same end of the Praecis II that the RS 232 and power input jacks are located Care should be taken not to short circuit these outputs or to connect them to other voltage sources If your primary application for the Praecis II is as a frequency standard you should consider operat ing the LED indicators in the Signal Quality Mode Refer to Chapter 6 Indicator Mode Button details In this mode you will always know whether the Praecis II is currently locked to a CDMA signal while you are performing measurements based on its 10 MHz output frequency The holdover accuracy of the standard TCXO will degrade to the 5 x 10 level fairly quickly following CDMA signal loss depending upon the ambient temperature environment 10 Praecis Il User Manual EndRun C VAN Fr TECHNOLOGIES General Serial 1 0 Operation Chapter Three Control and Status Commands This chapter will describes the ASCII protocol supported by the Praecis II For the RS 232 serial I O port physical and electrical characteristics see Appendix D Specifications The Praecis II commands are NOT case sensitive It accepts input command
78. ve been added to the FLTSTAT command response These are the Time Input Fault and the Main Osc Failure See FL TSTAT in Chapter 3 Control and Status Commands for details Version Information In response to the vER command the Praecis sends firmware and FPGA version information This message is slightly different between the Praecis II and the Praecis Cf See Chapter 3 Control and Status Commands for a description of this command Praecis II version information Praecis II FW 6010 0063 000 v 1 00 Jun 25 2010 16 41 39 FPGA 6020 0008 000 v 01 lt CR gt lt LF gt Praecis Cf version information Praecis Cf FW 6010 0001 000 v 1 00 Sep 18 2007 16 41 39 FPGA 6020 0001 000 v 01 lt CR gt lt LF gt Additional Commands The following commands are new and did not exist in the Praecis Cf FLTMSG and command specific HELP See Chapter 3 Control and Status Commands for more information on these new com mands North American PCS The major difference between the Praecis II and the Praecis Ct is that the Praecis II can synchronize to both North American CDMA cellular frequencies 800 MHz and PCS frequencies 1900 MHz The Praecis Ct would only utilize the cellular frequencies Adding the capability to use the North American PCS frequencies is a big benefit as the Praecis will now operate in some areas where it previously could not 50 Praecis II User Manual BACKWARDS COMPATIBILITY The channelset command has been changed slightly by a
79. you have a cellular CDMA phone see if it will work in digital mode If it will then your Pr cis II may be damaged and should be returned to the factory for repair or exchange Mount the Praecis II Place the Praecis II in the previously surveyed location near the computer Make sure that the antenna is not blocked by metallic objects that are closer than about one meter Ideally it should be mounted vertically as the transmitted signals are vertically polarized When indoors however mul tipath conditions may exist This means that reflected signals may be present with either vertical or horizontal polarization so your unit might work in either orientation After mounting the unit verify that it will still acquire and track the CDMA signals Connect the Serial Port 1 Shutdown the computer and disconnect power from the Praecis II 2 Connect one end of the RJ 45 CAT 5 patch cable to the RS 232 jack on the Praeis II Connect the other end of the RJ 45 CAT 5 patch cable to the RJ 45 jack on the RJ 45 to DB9F adapter connector 3 Connect the DB9F connector to the appropriate serial I O port on the computer If the serial I O port on your computer does not have a DB9M connector you may need to use an adapter Refer to Appendix D Specifications for details on the RS 232 signal wiring Remember which port you are using because you will need to know that in order to set up the terminal software 4 Power up the computer Test the Serial Port

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