1. Manuals
  2. Brands
  3. TrueTime Manuals
  4. GPS
  5. XL-DC
  6. Manual

TrueTime XL-DC Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

sales@artisantg.com
artisantg.com
(217) 352-9330 |
|
Click HERE
Find the Microsemi / Symmetricom / TrueTime 142-400-50 at our website:

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the XL-DC and is the answer not in the manual?

Questions and answers

Summary of Contents for TrueTime XL-DC

  • Page 1 (217) 352-9330 | Click HERE Find the Microsemi / Symmetricom / TrueTime 142-400-50 at our website:...
  • Page 2 Model XL-DC Serial Number__________________ September 15, 1997 Revision E...
  • Page 3 (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation I:\Notices\FCC-A.DOC Rev. H TrueTime, Inc. • 2835 Duke Court • Santa Rosa, CA 95407 707-528-1230 • F 707-527-6640 HONE www.truetime.com...
  • Page 5 Addendum for 142-603 Antenna Downconverter Assembly PHYSICAL SPECIFICATIONS Antenna Downconverter Size: 4.4 in. dia. x 2.1 in. (11.17 cm. dia. x 6.85 cm.) Note: Antenna DownConverter Units are mounted on a 12-inch long PVC nipple with a 3/4-inch Male Pipe Thread (MPT) on both ends. The above specified overall lengths of the Antenna DownConverter Units are therefore increased by approximately 11.25 inches, when the mounting nipple is included.
  • Page 6 Addendum for 142-612 Antenna Assembly PHYSICAL SPECIFICATIONS Antenna Size: 2.625 in. dia. x 1.5 in. (6.67 cm. dia. x 3.81 cm.) Note: The Antenna is mounted on a 12-inch long PVC nipple with a 3/4-inch Male Pipe Thread (MPT) on both ends. The above specified overall length of the Antenna. Units are therefore increased by approximately 11.25 inches when the mounting nipple is included.
  • Page 7 BATTERY, AS RECOMMENDED BY THE MANUFACTURER.” If the battery is replaced, it must be disposed of or recycled in accordance with all local, state, and federal laws. Batteries may be returned to TrueTime, Inc. for disposal. DISPOSAL.ADD 1 of 1...
  • Page 8 Please be advised that there may or may not be references in the text of this manual to schematic drawings. TrueTime’s general policy is to not include schematics because they may contain proprietary information. If you require copies of any schematic,...
  • Page 9 MODEL 151-XXX-XXX Installed Options Checklist GPS-XL MODULE OPTION(S) Down Converter TTL Time Code Output ) IRIG B ) IRIG E ) IRIG H TTL Frequency Output(s) ) 10 MPPS ( ) 5 MPPS ) 1 MPPS SINE Frequency Output(s) ) 10 MHz ) 5 MHz ) 1 MHz Alarm Output (open collector)
  • Page 10 RS-232/RS-422 CONNECTION 1-62 SERIAL DATA FORMAT 1-63 EXCLUSIVE USE INSTALLATION OVERVIEW PROCEDURE SPECIAL CONSIDERATIONS FOR EXTERNAL OSCILLATOR CONTROL OPTION RACK MOUNTING OPERATION INTRODUCTION GENERAL OPERATION XL-DC START-UP SATELLITE ACQUISITION 3-10 OPERATIONAL MODES 3-11 AUTO MODE 3-12 SURVEY MODE 3-13 TIME MODE...

  • Page 11: Table Of Contents

    TABLE OF CONTENTS (Continued) SECTION TITLE III (Cont.) OPERATION 3-20 TIME QUALITY INDICATION 3-21 FRONT PANEL INTERFACE 3-22 NUMERIC DISPLAY 3-23 ALPHANUMERIC DISPLAY 3-24 TIME PUSH-BUTTON 3-25 STATUS PUSH-BUTTON 3-26 POSITION PUSH-BUTTON 3-27 KEYPAD OPERATION 3-28 SELECTING FUNCTIONS AND ENTERING DATA 3-99 KEYPAD FUNCTION LIST 3-100...
  • Page 12 TABLE OF CONTENTS (Continued) SECTION TITLE III (Cont.) OPERATION 3-173 KEYPAD FUNCTION 73 - REQUEST/SET ALARM STATUS/CONTROL 3-179 KEYPAD FUNCTION 79 - WARM START 3-197 GENERAL SERIAL INPUT AND OUTPUT FORMAT 3-198 SERIAL ERROR MESSAGES 3-199 SERIAL FUNCTION LIST 3-201 SERIAL FUNCTION F01 - TIME ZONE ENTRY/REQUEST 3-202 SERIAL FUNCTION F02 - 12/24 HR FORMAT ENTRY/REQUEST...
  • Page 13 TABLE OF CONTENTS (Continued) SECTION TITLE CONFIGURATION/ASSEMBLY DRAWINGS NOT USED VIII IRIG B, IRIG H AND IRIG E TIME CODE FORMATS INTRODUCTION IRIG CODE FORMAT WORST-CASE TIME ERROR FLAGS 8-10 SPECIAL IRIG B TIME CODE FORMAT (EMBEDDED GPS DATA OPTION) FIGURE 8-1 IRIG B TIME CODE FIGURE 8-2 IRIG E TIME CODE FIGURE 8-3 IRIG H TIME CODE...
  • Page 14 FIBER OPTIC LINK OPTION XXVI CODE OUTPUT OPTION XXVII NTS-XL NETWORK TIME SERVER OPTION XXVIII PTTI INTERFACE OPTION XXXIX N8 FREQUENCY SYNTHESIZER NETWORK INTERFACE CARD XXXI 1, 5, 10 SINE XXXII HAVE QUICK II...
  • Page 15 However, operation to specified stability requires four or more satellites. When no satellites are in view, the XL-DC will continue to output its signals using either the internal (or OPTIONAL external) disciplined oscillator.
  • Page 16 By purchasing any product from TrueTime the Buyer consents to and agrees that the Buyer's sole and exclusive remedy for any damages or losses incurred by the Buyer as a result of TrueTime's breach of its one-year Limited Warranty for defects in materials and workmanship or otherwise in connection with any claim respecting the product shall be limited to the repair or replacement of the product or a refund of the sales price of the product.
  • Page 17 1-10 PHYSICAL SPECIFICATIONS The XL-DC is a 19” rack-mounted product with the following physical specifications: XL-DC Receiver Size: 1.75 in x 17.0 in x 9.70 in (4.45 cm x 43.18 cm x 24.64 cm) Standard 19" EIA Rack System, hardware included, slides optional.
  • Page 18 BATTERY, AS RECOMMENDED BY THE MANUFACTURER." If the battery is replaced, it must be disposed of or recycled in accordance with all local, state, and federal laws. Batteries may be returned to TrueTime, Inc. for disposal. 1-14 TIMING/FREQUENCY PERFORMANCE SPECIFICATIONS...
  • Page 19 User-selectable on Models XL-DC-601/602 from 300, 600, 1200, 2400, 4800, 9600 and 19200 bps. Fixed on Model XL-DC-600 (user-specified). Data Bits: User-selectable on Models XL-DC-601/602 from 7 or 8. Fixed on Model XL-DC-600 (user-specified). Parity: User-selectable on Models XL-DC-601/602 from even, odd or none.
  • Page 20 1 PPS pulse will be as stable as the internal (or external if so configured) oscillator of the XL-DC. The 1 PPS output is capable of driving a 50 Ω load. This output is valid whenever the XL-DC has an accurate position and is tracking at least one satellite.
  • Page 21 OUTPUT OPTIONS: (Refer to installed options checklist.) 1-30 TTL TIME CODE(S) IRIG B, IRIG E OR IRIG H (OPTION) An IRIG B, IRIG E, or IRIG H output(s) DC Level Shift Modulation output(s) are connected to rear panel BNC connector(s). Refer to Section VIII for a description of these codes. The DC level shift modulation output(s) provides TTL levels into 100 Ω...
  • Page 22 Each pulse edge is aligned to within a few nanoseconds of the XL-DC’s 1 PPS output pulse, with the rising edge at the start of the minute. The as shipped default values are:...
  • Page 23 -- either -5 to +5 VDC or 0 to +10 VDC (refer to 87-6XX configuration drawing JP5). The output impedance is 100 Ω. Refer to Keypad and Serial Functions 07 and 14 for configuring the XL-DC to support this option.
  • Page 24 (refer to 87-6XX configuration drawing JP7 -- factory default = 50 Ω). The rising edge of the pulse is measured with respect to the XL-DC time to 30 ns. Refer to Keypad or Serial Function F28 for details concerning the use of this input.
  • Page 25 1-60 SERIAL INTERFACE The Serial Port can be connected to a terminal or computer. These instructions assume that a terminal is connected. The SERIAL connection and data format are explained in the following sections. The Serial functions are explained in manual Section III. 1-61 RS-232/RS-422 CONNECTION A male 9-pin D connector (9-pin D) provides a serial, asynchronous, bi-directional data port.
  • Page 26 1-62 SERIAL DATA FORMAT The default Serial format, as shipped, is: Data Rate: 9600 bits/second Word Length: 7 bits Parity: Even Stop Bits: The format cannot be changed via the Serial Port. Factory or Keypad (see “KEYPAD FUNCTION 04 - SERIAL PORT SETUP”) configured formats available are: Baud Rates: 300, 600, 1200, 2400, 4800, 9600,19200...
  • Page 28 (about 100 km) or better. When the XL-DC has phase locked its oscillator to the GPS signals and has set its 1 PPS output to the specified accuracy, the terminating character of the Serial Function F08 continuous time output string will change from a "?"...
  • Page 29 Initially following power-up, the optional open collector alarm output will provide a high impedance to ground. When the XL-DC is tracking satellites and is controlling the local oscillator and 1 PPS output to within specified accuracy to UTC, this output will provide a low impedance to ground. Thereafter, whenever the XL-DC outputs are not within specifications, this output will provide a high impedance to ground.
  • Page 30 XL-DC. For the Model XL-DC-600, all references to the front-panel keypad and displays should be ignored as they are not available on that unit. For the Model XL-DC-601, all references to the large numeric LCD time display should be ignored as it is not available on that unit.
  • Page 31 Seconds UNLOCK Not tracking satellites After power up, the XL-DC will send continuous time with a one second update rate over the Serial Port. The format of this output string is described in section 3-208, "SERIAL FUNCTION 08 - CONTINUOUS TIME ONCE PER SECOND ENABLE". Prior to satellite acquisition the time either displayed or sent over the Serial Port is battery-backed GPS time.
  • Page 32 "MODE: AUTO 1 SAT", giving the positioning mode of the GPS core unit. The second line indicates "sats ##", giving the PRN number of the highest satellite being tracked. At this time, the position of the XL-DC may be placed in the proper hemisphere, narrowing the search for possible SV's.
  • Page 33 This will be indicated on the status display. Though these 0-D and 2-D fixes will not go into the position average, they will be used to control the time and frequency outputs of the XL-DC. When the XL-DC is synchronized to UTC using the approximate position found, the unlock and time error annunciators are extinguished, thus indicating the end of the Current Position Search phase of AUTO mode.

  • Page 34: Time Quality Indication

    If the XL-DC determines that it has been moved by more than 1 km, it will automatically set itself into the AUTO mode of operation.

  • Page 35: Front Panel Interface

    3-21 FRONT PANEL INTERFACE The primary user interface on Model XL-DC-600 is the Serial Port (refer to the section on Serial functions). On Models XL-DC-601 and XL-DC-602, the front panel is the primary user interface. Input is via three front panel push-buttons and a 16-key keypad, output is via a two line 32-character alphanumeric display that provides status and various function information.

  • Page 36: Time Push-Button

    3-24 TIME PUSH-BUTTON The large numeric display shows time-of-year continuously. However, pressing the TIME push-button places the equivalent time-of-year and the date on the alphanumeric display. The format of the date is day-of-week, month, day-of-month, year. 3-25 STATUS PUSH-BUTTON The STATUS push-button is used to place current clock status on the alphanumeric display. Additionally, PRESSING THE STATUS BUTTON WILL ABORT ANY KEYPAD FUNCTION CURRENTLY IN PROGRESS.

  • Page 37: Keypad Operation

    The third time the POSITION button is pressed, the display will show: Altitude Altitude +000050 Meters +000152 Feet The fourth time the POSITION button is pressed, the display will show: Pdop +2.06 which is the position dilution of precision (PDOP). Each press of the POSITION button will cause the display to scroll through these four readings.

  • Page 38: Selecting Functions And Entering Data

    Use the left or right arrow keys to move the cursor beneath the character that you wish to edit. Use the up or down arrow keys to scroll through the possible choices for that character. 3-28 SELECTING FUNCTIONS AND ENTERING DATA The various keypad functions are listed in the following KEYPAD FUNCTION LIST.

  • Page 39: Keypad Function 00 - Keypad Help Function

    3-100 KEYPAD FUNCTION 00 - KEYPAD HELP FUNCTION Use keypad Function 00 to obtain a short description of all keypad functions available. Press "FUNC ENTR", then "0" "0". The display will show: up, down keys to view list... Press any key to see the next display: Func/enter key to call function Press any key to see the next display, the first entry in the keypad function description list:...

  • Page 40: Keypad Function 03 - Time/Date Entry

    Press "FUNC/ENTR", then "0" "2". The display will show: 12/24 hr Format or 12/24 hr Format Press the up or down arrow keys to toggle between 24 and 12. When the display shows the desired format, press "FUNC/ENTR" to enter your choice. 3-103 KEYPAD FUNCTION 03 - TIME/DATE ENTRY Use Function 03 to enter time and date.

  • Page 41: Keypad Function 05 - Time Quality Enable/Setup

    The default values on power-ups will be those in use prior to power-down. Press "FUNC/ENTR, then "0" "4". The display will show: Ser port setup Baud rate 9600 Press the up or down arrow keys to scroll through the possible baud rate choices. When the display shows the desired baud rate, press "FUNC/ENTR"...

  • Page 42: Keypad Function 06 - Keypad Lockout Enable

    Press the up or down arrow keys to toggle between "on" and "off". When the display shows the desired state, press "FUNC/ENTR". The display will show: First tq flag: 00000001000ns or the current value. Press the right or left arrow keys to position the cursor beneath the digit that you want to change.

  • Page 43: Keypad Function 07 - External Oscillator Enable (Option)

    If the XL-DC acquired valid time, but subsequently lost lock to the satellite signals, the time output will begin to drift. This drift is dependent on the stability of the internal or the optional external oscillator and the accuracy to which it had been set on frequency prior to the outage.
  • Page 44 60 C temperature stability of the external oscillator that is being controlled. This value is used by the XL-DC to determine the optimal control loop averaging time so that ° performance under environmental stress of up to 8.3 C per hour temperature change does not degrade the output frequency stability significantly below that of the GPS system stability.

  • Page 45: Keypad Function 16 - Emulation Mode Enable

    The emulation mode cannot be enabled or disabled via either communications port. The Mark II command set is composed of selected commands used on earlier TrueTime synchronized clocks. Therefore, most Serial programs written for use with these earlier models may be used with the current Mark III.

  • Page 46: Serial Port Emulation Commands

    GPS-DC Mark II GPS Synchronized Clock. Most customer programs written to interface with the Mark II Serial Port will also interface with the XL-DC Serial Port if the emulation mode is enabled with Keypad Function 16. Refer to the following table for the available emulation mode commands.

  • Page 47: Mode F - Format The Time Message

    The time quality character prior to satellite signal acquisition will be "?". Refer to SERIAL FUNCTION F13 - WORST-CASE TIME ERROR REQUEST for an explanation of worst-case error. The carriage return character <CR> start bit begins on the second, +0 to +1 bit period or +1 ms, whichever is larger. To halt the output of time once each second, send another command character to the Serial Port.

  • Page 48: Mode R - Reset To Default And Mode C

    Sample Entry: FDDD/HH:MM:SS.mmmQ<CR> Response: <SOH>360/22:01:25.602*<CR><LF> Sample Entry: FXXX hh,mm,ss XXXX<CR> Response: <SOH> 22,01,25 <CR><LF> Sample Entry: FDDDAXXT<CR> Response: <SOH>360A:01:25.602*<CR><LF> 3-116.4 MODE R - RESET TO DEFAULT AND MODE C Use Mode R to reset to the default format and return to Mode C. Send the command character R to the Serial Port and the port will respond by outputting time in the default format once per second.

  • Page 49: Keypad Function 17 - Slow Code Setup (Option)

    If a command character T is sent to the Serial Port prior to the acquisition of time, the Serial Port will output time elapsed from power-up. 3-117 KEYPAD FUNCTION 17 - SLOW CODE SETUP (OPTION) Use Function 17 to control the Slow Code output. This output provides one pulse per minute, primarily for placing timing marks on drum recorders.

  • Page 50: Keypad Function 18 - Software Version Request

    PPS input. In this mode the reported time interval is expressed as the fractional part of a second between the XL-DC 1 PPS which starts the count and the external 1 PPS which stops it. The Event Timing (ET) mode is suited to randomly occurring events whose time of occurrence is needed to a high accuracy.

  • Page 51: Keypad Function 29 - Frequency Measurement Input (Option)

    Press "FUNC/ENTR", "2","9". The display will show: External Freq 10 MHz Use the up or down arrow keys to select the correct input frequency for the XL-DC to measure. Press "FUNC/ENTR" to enter the selection. The display will now show: Meas Interval...

  • Page 52: Keypad Function 50 - Position Entry/Request

    GPS core receiver at new installations or after loss of non-volatile RAM back-up power. The as-shipped default for position is that of the TrueTime factory in Santa Rosa, California. The position value on power-up will be that in use prior to power-down.

  • Page 53: Keypad Function 51 - Antenna Cable Delay Entry/Request

    Use Function 52 to request or enter a fixed delay to be used for compensating the timing outputs for distribution cable delays between the XL-DC and the point of use of the timing signals. Antenna cable delay compensation should not be performed using this function. Use Function 51 for antenna cable delay.

  • Page 54: Keypad Function 55 - Altitude Units Entry/Request

    This function provides a means of setting an accurate, surveyed position for use in the TIME mode of operation. Positions provided to the XL-DC via Function 56 should be more accurate than 10 meters, otherwise better results may be obtained via AUTO mode (unless satellite visibility at the site is too poor to provide three dimensional positioning).

  • Page 55: Keypad Function 60 - Satellites List Request

    Enter average position? No This choice will only be made available if the XL-DC is operating in the TIME mode. Use the up or down arrow key to toggle to the desired response and press "FUNC/ENTR" to either cancel entry or complete it.

  • Page 56: Keypad Function 65 - Satellite Select

    Use Function 65 to select specific satellites for the receiver to track and to deselect satellites, i.e., instruct the XL-DC to ignore certain satellites. Selections will be retained in non-volatile memory. Press "FUNC/ENTR", then "6" "5". The display will show:...
  • Page 57 DST function. Some local jurisdictions enter and leave DST at times other than those set by U.S. federal law. Therefore, TrueTime has included a "Manual" choice which allows the user to override the times of entry into and exit from DST by selecting his own. If "Manual" is selected for the...

  • Page 58: Keypad Function 68 - Year Entry (Gps Epoch Management)

    assuming the entry time was 2:00 a.m.. The sequence upon exit from DST is: 01:59:58 01:59:59 01:00:00 01:00:01 assuming the exit time was 2:00 a.m.. If the DST function is enabled or disabled when DST is already in effect, the display will take several seconds to respond.

  • Page 59: Keypad Function 69 - Select Local/Standard/Gps/Utc Time

    3-169 KEYPAD FUNCTION 69 - SELECT LOCAL/STANDARD/GPS/UTC TIME Use Function 69 to select between LOCAL, STANDARD, GPS or UTC time. The selected time type will be displayed and sent out on the IRIG B and Serial Ports. The as-shipped default is the UTC time format.

  • Page 60: Keypad Function 72 - Fault Status Request

    3-172 KEYPAD FUNCTION 72 - FAULT STATUS REQUEST Keypad Function 72 displays the status of certain fault detectors within the XL-DC. These are currently limited to the status of the Antenna feed circuit, the PLL synthesizer lock status and GPS lock status.

  • Page 61: Keypad Function 73 - Request/Set Alarm Status/Control

    where XXX is one of "OK", "OPEN", or "SHORT". Pressing the up or down arrow keys or "FUNC/ENTR" will display the next status indicator: Fault Status PLL: XXXXXXXX where XXXXXXXX is either "OK" or "UNLOCKED". Pressing the up or down arrow keys or "FUNC/ENTR"...
  • Page 62 The remaining items are fault conditions, which can be individually enabled or disabled from affecting the alarm output(s). The <en> field is either "En" or "Dis" and can be toggled with the Up/Down arrow keys to Enable or Disable each fault condition. These mask settings will be changed only if requested at the end of all of the fault items.
  • Page 63 where <timeout> is in seconds between 0 and 86400 (1 day). This number sets the delay from when the time error threshold is exceeded and when the Timeout fault occurs. Minor Alarm: <en> Time Error: <TE status> <TE status> can be "OK" or "Fault" and indicates that the estimated time error (available through Function 13) exceeds the alarm time error threshold.
  • Page 64 Models XL-DC-600 and XL-DC-601 have a Red/Green LED on the front panel. In general, faults only affect the LED if they are enabled. However, even if there is no enabled major or minor fault, the presence of the time error fault is indicated by a solid Green LED (if BLINK = ENABLE).

  • Page 65: Keypad Function 79 - Warm Start

    In all Models of the XL-DC, the 87-6XX GPS-XL sub-assembly open collector alarm output at P46B pin 1 has the following states: (High Z) Power off (High Z) Error, major or minor enabled alarm fault. (Low Z) Normal, no major or minor enabled alarm faults.

  • Page 66: General Serial Input And Output Format

    Press the up or down arrow keys to toggle between "No" and "Yes". When the display shows the choice you desire, press "FUNC/ENTR". If you choose "yes" this will initiate a warm start. To exit this function without performing a warm start press the "STATUS" key. 3-180 through 3-196 reserved SERIAL FUNCTIONS 3-197 GENERAL SERIAL INPUT AND OUTPUT FORMAT...

  • Page 67: Serial Error Messages

    Incorrect entry may result in an error message as described under "SERIAL ERROR MESSAGES". Correct entries are acknowledged with OK<CR><LF>. 3-198 SERIAL ERROR MESSAGES The Serial Port will respond with the message "ERROR 01 VALUE OUT OF RANGE" if the input string was in the correct format but contained a value, probably numeric, that was out of the range of acceptable values.

  • Page 68: Serial Function List

    3-199 SERIAL FUNCTION LIST At power-up, the Serial Port outputs time once per second as described in Function F08 until it receives a CTRL-C character (Hex 03). Then any of the following commands may be used: POWER-UP FUNCTION DESCRIPTION AS SHIPPED DEFAULT Time Zone Entry/Request Last Entry...

  • Page 69: Serial Function F01 - Time Zone Entry/Request

    Use Serial Function F01 to select or determine the time zone offset. NOTE: Function 01 will provide time zone offset only when the XL-DC is in LOCAL or STANDARD time mode (refer to Function 69). To request the offset, send F01<CR> to the Serial Port. The port will respond with the following character string: F01<SEP><SIGN><HH>:<MM><LT>...

  • Page 70: Serial Function F03 - Time/Date Entry/Request

    Sample request: F02<CR> Response: F02 12<CR><LT> To select 24 hour format, send the following character string: Sample entry: F02 24<CR> Response: OK<CR><LF> 3-203 SERIAL FUNCTION F03 - TIME/DATE ENTRY/REQUEST Use Serial Function F03 to enter or request time and date. To request time and date, send F03<CR> to the Serial Port.

  • Page 71: Serial Function F05 - Time Quality Enable/Setup

    1000ns, 10000ns, 100000ns and 1000000ns. The XL-DC will retain the values in use at power-down and use them for subsequent power-ups. The acceptable threshold value range is 200 ns to 40000000000 ns.

  • Page 72: Serial Function F06 - Keypad Lockout Enable

    3-206 SERIAL FUNCTION F06 - KEYPAD LOCKOUT ENABLE Use Serial Function F06 to enable or disable the keypad lockout feature. As shipped, the keypad lockout is disabled. The state of the keypad lockout on power-up will be the same as it was at power- down.

  • Page 73: Serial Function F08 - Continuous Time Once Per Second Enable

    To enable or disable the external oscillator, send a character string with the following format: Sample entry: F07 OFF<CR> or F07 ON<CR> Response: OK<CR><LF> 3-208 SERIAL FUNCTION F08 - CONTINUOUS TIME ONCE PER SECOND ENABLE The Internal Trimble SVeeSix time will output once per second at the Serial Port prior to acquisition of satellite signals.

  • Page 74: Serial Function F09 - Time On Request Enable

    3-209 SERIAL FUNCTION F09 - TIME ON REQUEST ENABLE When the Serial Port receives the command string F09<CR>, it waits for a request in the form of an upper-case ASCII character T to output the time-of-day string. After a T is received, the current time is saved (with a resolution of 1 ms) in a buffer and is then transmitted to the port.
  • Page 75 day-of-year hours minutes seconds ASCII decimal point milliseconds colon separator time quality character position characters for this position are: < >, <.>, <*>, <#> and <?> If non-volatile memory is corrupted due to battery failure or other cause, the format string will be set to the "null"...

  • Page 76: Serial Function F13 - Worst-Case Time Error Request

    00.000000200 seconds. Time error begins to accumulate when the receiver loses contact with the satellite signal. The XL-DC calculates the worst-case time error based on the stability of the time base in use, either the internal or optional external oscillator (refer to Function 14), and the time elapsed since loss of lock.

  • Page 77: Serial Function F14 - External Oscillator Parameter Entry/Request

    Sample request: F13<CR> Response: F13 40.000000000<CR><LF> 3-214 SERIAL FUNCTION F14 - EXTERNAL OSCILLATOR PARAMETER ENTRY/REQUEST (OPTION) Use Serial Function F14 to set or determine the external oscillator parameters. These parameters are used to properly configure the input circuitry and to calculate the control coefficients for disciplining the external oscillator.

  • Page 78: Serial Function F17 - Slow Code Setup (Option)

    The lengths can range from 0 to 59 seconds, whole numbers only. A length of 0 means that the pulse is absent. Each pulse edge is aligned to within a few nanoseconds of the XL-DC’s 1 PPS pulse, with the rising edge at the start of a minute.

  • Page 79: Serial Function F18 - Software Version Request

    Send the string: F18<CR> and the XL-DC Serial Port will respond with a string no longer that 80 characters. example: TRUETIME Mk III sys ver 020 GPS-XL v1.036 182-6007v015<CR><LF> This string indicates that the system software is version 20, the GPS-XL version is 1.036 and the XL-DC specific software part number is 182-6007 version 015.
  • Page 80 <SEP> one or more separator characters: either space, comma or tab <START TIME> = time to start the pulse, formatted like: <DAY>:<HOURS>:<MIN>:<SEC>.<MSEC> <STOP TIME> = time to stop the pulse, formatted like: <DAY>:<HOURS>:<MIN>:<SEC>.<MSEC> <CR> ASCII Carriage Return character (HEX 0D) <LF>...

  • Page 81: Serial Function F28 - Time Interval/Event Timing Input (Option)

    Either the Start Time or the Stop Time may be replaced with a semicolon, in which case that item will be unchanged by the command. Sample entry: F26 ; XXX:XX:10:00.000<CR> Response: OK<CR><LF> This entry will leave the Start Time set to whatever it was before, and will change the Stop Time to 10 minutes after the hour.

  • Page 82: Serial Function F29 - Frequency Measurement Input (Option)

    This function provides the capability to measure the frequency of an externally applied 1, 5, or 10 MHz signal very accurately with respect to the disciplined XL-DC oscillator. The resolution of the measurements is 6 parts in 10 divided by the Measurement Interval.
  • Page 83 An important feature of this implementation is that "zero dead time" frequency measurements are performed. In essence the position in XL-DC internal time of a zero crossing of the externally applied frequency being measured is recorded, or "timestamped", once per measurement interval with 60 picosecond resolution.
  • Page 84 This mode is useful in matching the data rate of some other process which is concurrently being logged and is not necessarily periodic or synchronized with the XL-DC. The measurement returned in either the QUERY or PERIODIC modes is sent in this format:...

  • Page 85: Serial Function F50 - Position Entry/Request

    GPS core module at new installations or after loss of non- volatile RAM back-up power. The as-shipped default for position is that of the TrueTime factory in Santa Rosa, California. The position on power-up will be the same as it was prior to power-down. To determine the present position send F50<CR>...

  • Page 86: Serial Function F51 - Antenna Cable Delay Entry/Request

    Sample request: F50<CR> Response: F50 N 38d23'51.3" W 122d42'53.2" 58m pdop 2.69<CR><LF> To enter a position send a character string with the following format. Latitude, longitude or altitude may be omitted in the string provided they are replaced with a semicolon (;) character. The altitude units may be feet or meters.

  • Page 87: Serial Function F52 - Distribution Cable Delay Entry/Request

    Use Serial Function F52 to enter or request the distribution cable delay for compensating the timing outputs for delays between the XL-DC and the point of use of the timing signals. Antenna cable delay compensation should not be performed using this function. Use Function F51 for antenna cable delay.

  • Page 88: Serial Function F53 - Operational Mode Entry/Request

    3-253 SERIAL FUNCTION F53 - OPERATIONAL MODE ENTRY/REQUEST Use Serial Function F53 to select the operational mode, either AUTO, SURVEY (STATIC or DYNAMIC) or TIME. For an explanation of these modes refer to section 3-10, "OPERATIONAL MODES". The power-up default is the mode in use at power-down. To request the present mode, send F53<CR> to the Serial Port.

  • Page 89: Serial Function F56 - Average Position Entry/Request

    This function provides a means of setting an accurate, surveyed position for use in the TIME mode of operation. Positions provided to the XL-DC via Function F56 should be more accurate than 10 meters, otherwise better results may be obtained via AUTO mode, unless satellite visibility at the site is too poor to provide three-dimensional positioning.

  • Page 90: Serial Function F60 - Satellites List Request

    COUNT <NNNNN> / 90000 NNNNN is the total number of fixes in the average, 90000 is the total number of fixes required to complete the position average process. ENTERED Indicates that the current averaged position was obtained via operator entry. <LT>...

  • Page 91: Serial Function F65 - Satellite Selection

    3-261 through 3-264 reserved 3-265 SERIAL FUNCTION F65 - SATELLITE SELECT Use Serial Function F65 to select specific satellites for the receiver to track or to deselect, i.e., instruct the XL-DC to ignore certain satellites. Send the string of the form: F65<SEP><REQUEST><SEP>NN<SEP>NN<SEP>NN<CR> F65<SEP><REQUEST>ALL<CR>...

  • Page 92: Serial Function F66 - Daylight Saving Enable

    Use of any other satellite number will result in the error message "ERROR 04 EXCLUSIVE USE". NOTE: The XL-DC Receiver requires 24 hours after turn-on to complete the satellite list. 3-266 SERIAL FUNCTION F66 - DAYLIGHT SAVING ENABLE Use Serial Function F66 to enable, disable or set the entry or exit times for DST. The as-shipped default is "Off".

  • Page 93: Serial Function F68 - Year Entry (Gps Epoch Management)

    where: = time to enter DST in 24-hour format <INHOUR> <SEP> = one or more separator characters, either space comma or tab characters. For output strings this will be a single space character = which week to enter DST, 1, 2, 3, 4 or 0 (for last). <INWEEK>...

  • Page 94: Serial Function F69 - Select Local/Standard/Gps/Utc Time

    Local time requires the setting of Daylight Saving Time with F66, (Daylight Saving Enable). Use Serial Function F69 to request or set the XL-DC time format. To request the current time type used, send F69<CR> to the Serial Port. The port will respond with the following character string: F69<SEP><HH><LT>...

  • Page 95: Serial Function F71 - Oscillator Statistics Request

    where: ASCII character F function number <SEP> = one or more separator characters; either space, comma or tab <TT> = Time Type. Either STANDARD, LOCAL, GPS or UTC <LT> = line terminator, either a carriage return and line feed for output strings or a carriage return only for input strings Sample request: F69 STANDARD<CR>...

  • Page 96: Serial Function F72 - Fault Status Request

    3-272 SERIAL FUNCTION F72 - FAULT STATUS REQUEST This function displays the current status of faults in the XL-DC sub-systems. Currently, the status of the antenna, PLL synthesizer lock status and the GPS lock status are the only such faults being monitored.
  • Page 97 Position Unknown, Highly Degraded Accuracy and Stability, Not Locked Position and Time Unknown, Not Locked Auto Mode Time Mode Survey Mode Differential Mode Number of Current Satellites used in solutions thru No timing source GPS is timing source AUX is timing source IRIG is timing source Currently not used Currently not used...
  • Page 98 Currently not used Currently not used Currently not used <CR> ASCII carriage return character <LF> ASCII line feed character Sending: F73<SP>LATCH<CR> returns: F73<SP>LATCH<SP>M12345678<SP>m12345678<CR><LF> which shows the latched faults, if any, that have occurred since the last time that the latch was cleared. These may or may not continue to be present in the non-latched indications.
  • Page 99 Oscillator Tuning Voltage Alarm Enabled Oscillator Tuning Voltage Alarm Disabled Non-Volatile RAM Battery Voltage Alarm Enabled Non-Volatile RAM Battery Voltage Disabled Initial Acquisition Mode Alarm Enabled Initial Acquisition Mode Alarm Disabled Currently not used Currently not used Currently not used The command returns: OK<CR><LF>...
  • Page 100 OK<CR><LF> Model XL-DC-600 and XL-DC-601 have a Red/Green Status LED that is controlled by Function 73. In general, faults only affect the Status LED if they are enabled. However, even if there is no enabled major or minor fault, the presence of the time error fault is indicated by a solid Green Status LED if BLINK = ENABLE (default).

  • Page 101: Serial Function F79 - Warm Start

    enables the LED to blink under the conditions given above. The response is: OK<CR><LF> if successful. Sending: F73<SP>BLINK DISABLE<CR> disables the LED from blinking in all but the processor reset mode as given above. Minor Alarm conditions may be delayed if power-on Minor Alarm SUPPRESS is set to a value (in seconds).
  • Page 102 Send the string F79<CR> and the Serial Port will respond by initiating a warm start. Sample entry: F79<CR> Response: OK<CR><LF>...
  • Page 103 (BCD) notation. The second segment encodes control functions. This segment is generally available for data of the user's choice. In the IRIG B code output of Model XL-DC, this segment may encode worst-case time error flags as explained below. Neither the IRIG H (OPTION) or IRIG E (OPTION) output from Model XL-DC encode control functions.
  • Page 104 GPS data may be encoded in the control function segment of the IRIG B code. This data, along with the worst-case time error flags (STANDARD), are present in the IRIG B code if this special option is ordered. This special IRIG B format is used as a timing source for TrueTime’s Model MAC-SG (560-5700).
  • Page 105 Figure 8-1 IRIG B Time Code TIME TIME FRAME 1 SECOND ON TIME TIME IN 0.01 SE CONDS B CD TIME-OF-Y EAR CONTROL FUNCTIONS SE CONDS MINUTES HOURS DA YS RE F 100 200 W EIGHTED CONTROL 10ms (TYP ICAL) DIGITS 5ms TY PICAL 0.1 SE COND P OS ITION B INARY 1 (TYP ICAL)
  • Page 106 Figure 8-3 IRIG H Time Code TIME TIME FRAME 1 MINUTE TIME IN SECONDS ON TIME BCD TIME-OF-YEAR MINUTES HOURS DAYS CONTROL FUNCTIONS 10 20 20 40 80 100 200 1-SEC WEIGHTED CONTROL DIGIT TYPICAL 10-SECOND POSITION IDENTIFIER TYPICAL 0.5 SEC TYPICAL 0.5 SEC DURATION 0.8 SECONDS BINARY 1 (TYPICAL)

This manual is also suitable for:

151-600151-601151-601-178-1151-602151-650151-652 ... Show all

Table of Contents

Save PDF