Page 1 ET6000, ET6010, ET6500 ExacTime GPS Time Code And Frequency Generator Covering Configurations: ET6000, ET6010, ET6500-TCXO ET6000, ET6010, ET6500-OCXO ET6000, ET6010, ET6500-RB1 Revision C User’s Guide 8500-0105 June, 2005...
Page 2: Table Of Contents
ET6000, ET6010, and ET6500 EXACTIME GPS TIME CODE AND FREQUENCY GENERATOR TABLE OF CONTENTS SECTION PAGE CHAPTER ONE GENERAL INFORMATION 1.0 INTRODUCTION ........................ 1-1 1.1 USER'S GUIDE SUMMARY ....................1-1 1.2 NAVSTAR/GPS DESCRIPTION ..................1-2 1.3 PRODUCT DESCRIPTION ....................1-3 1.4 SPECIFICATIONS.......................
Page 3 3.3.7 EXTERNAL FREQUENCY MEASUREMENT MENU SCREEN ....3-17 3.3.8 SINGLE EVENT LOG MENU SCREEN ............3-18 3.3.9 50/60HZ MEASUREMENT SCREEN ............... 3-19 3.3.10 AUTO DAYLIGHT SAVINGS MENU SCREEN ........... 3-20 3.3.11 MUX OUTPUT MENU SCREEN ..............3-21 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 4 3.4 CONFIGURATION OF REAR PANEL BNC CONNECTORS J4-J9......3-26 CHAPTER FOUR I/O PORT DATA INPUT/OUTPUT 4.0 INTRODUCTION ........................ 4-1 4.1 SYMMETRICOM FIRMWARE VERSION................ 4-3 4.2 UTC SYNC........................... 4-4 4.3 GPS SYNC..........................4-4 4.4 PRINT FREQUENCY OFFSET................... 4-4 4.5 PRINT TIME, STATUS, ERROR CODE, AND SATELLITE VEHICLE NUMBERS..4-4 4.6 PRINT POSITION........................
Page 5 5.2.4 LOCKED LED DOES NOT ILLUMINATE ............5-5 5.2.5 UNIT DOES NOT TRACK SATELLITES, ERROR MESSAGE/CODE – ANTENNA UNDERCURRENT ................5-5 5.2.6 COLD RESET ....................... 5-5 5.3 THEORY OF OPERATION....................5-6 5.3.1 GPS SYSTEM OPERATION................5-6 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 6 F ..............................B-4 G..............................B-4 H..............................B-5 I ..............................B-5 J ..............................B-6 K..............................B-6 L ..............................B-6 M ..............................B-7 N..............................B-7 O..............................B-8 P ..............................B-8 Q..............................B-9 R..............................B-9 S ..............................B-9 T ..............................B-10 U..............................B-10 V..............................B-10 W..............................B-11 X..............................B-11 Y..............................B-11 Z ..............................B-11 Symmetricom Inc ET6xxx ExacTime GPS TCode & FG (Rev C)
Page 7 GPS Option Motherboard (w/1 BNC output) ........C-75 GPS Opt 40B/40BP GPS Option Motherboard (w/3 BNC outputs) ........C-77 GPS Opt 48 Pulse Rate Module ................C-79 APPENDIX D ANTENNA REPLACEMENT KIT Antenna Replacement Kit ..............D-1 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 8: Chapter One General Information
Positioning System (GPS) Time Code and Frequency Generator (TC&FG). Excluding options and size, the only difference between the different configurations is the oscillator. The following are the available configurations and their respective oscillators: ET6000-TCXO 10MHz Voltage Controlled Temperature Compensated Crystal Oscillator. ET6010-TCXO...
Page 9: Navstar/Gps Description
Each satellite transmits a unique C/A code that reflects the satellite identity for acquisition and tracking. The C/A PRN code is a gold code of 1023 bits repeating at a one-millisecond rate. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 10: Product Description
GPS 1pps and an externally input 1pps (or it can measure an external frequency input – Models ET6000 and ET6010 only). It contains an RS-232 printer port. Optional features listed in Appendix C are available to meet specific requirements. Refer to the GPS Option/Connector Configuration sheet located in this manual for the options supplied with this instrument.
Page 11: Specifications
To change the outputs from the factory set standard configuration, see the paragraph titled “Timing Outputs” in Chapter Two and the paragraph titled “Optional Pulse Rate Outputs” in this section of the User’s Guide. Each output is via a 50Ω driver. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 12 (2) microseconds wide, positive edge on-time. It is capable of driving 10 LSTTL loads. To enable this output, on the GPS Main Assembly 100015, jumper J17 pins 7-8 (only). See Figure 2-3 in Chapter Two. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 13 100Hz 10Hz/1PPH* .1Hz 1PPM Models ET6000 and ET6010 output 10KHz and 10Hz. Model ET6500 outputs 2PPH and 1PPH. For further clarification and/or configuration of the above outputs, See Chapters Two and Three. ET6xxx ExacTime GPS TC & FG (Rev C)
Page 14: Accuracy
Second Menu Screen. Refer to Chapter Three. Also see paragraphs entitled, “Enable Time Interval,” “Disable Time Interval,” and “Request Time Interval,” in Chapter Four of this User’s Guide. EXTERNAL FREQUENCY MEASUREMENT (MODELS ET6000 AND ET6010 ONLY) Frequency Range 1Hz to 10MHz (discrete, whole numbers - not fractional parts).
Page 15: J12 Rs-232 I/O Interface
10MHz Sine Wave. OUTPUT AMPLITUDE OF CRYSTAL OSCILLATOR 1.0 volt peak-to-peak minimum clipped sine wave into 20KΩ load. Harmonics - 20dBc maximum. AGING RATE 1E-7 per day or ±1.0PPM maximum per year. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 16 TEMPERATURE STABILITY ±1 x 10 over a temperature range of –20ºC to +75ºC. OPERATING TEMPERATURE –20ºC to +75ºC. ALTITUDE Sea level to +50,000 feet. ELECTRICAL TUNING ±1PPM (minimum) / ±2PPM (maximum). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 17 0.55VRMS ±0.05VRMS into 50 ohms. AGING RATE ≤5 x 10 per month, 5 x 10 per year. OPERATING TEMPERATURE –20ºC to +70ºC measured at the base plate. STORAGE TEMPERATURE -55ºC to +85ºC 1-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 18: Primary Power
100KHz -147 dBc/Hz 1.4.7 PRIMARY POWER Models ET6000 and ET6010 utilize a Power Entry Module and the Standard Power Supply. Input Voltage AC = 85 to 264 VAC (47-440 Hz) @ less than thirty watts. DC = +120 to 373 VDC...
Page 19 Timing Relay - Common Contact TB1-7 Timing Relay - Normally Closed Contact TB1-8 50/60Hz Measurement Input - HI TB1-9 50/60Hz Measurement Input - LO TB1-10 Not Used TB1-11 Not Used TB1-12 Not Used 1-12 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 20: Dimensions
ExacTime Unit: C to +50 Antenna/Preamp: C to +85 STORAGE TEMPERATURE ExacTime Unit: C to +70 Antenna/Preamp: C to +100 HUMIDITY ExacTime Unit 95% (non-condensing) up to 40 Antenna/Preamp Unlimited. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 1-13...
Page 21: Additional Specifications
After 200 averages, the unit will have acquired its position and will switch automatically to the S (Stationary) mode. The number of position averages is user selectable via the RS-232 I/O. See paragraph titled “Number of Averages” in Chapter Four. 1-14 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 22: Signal Interruption
RPU to the GPS ExacTime Processor. The position data is three dimensional and available in a latitude, longitude, and altitude (WGS-84) coordinate frame. The GPS solutions are computed at typically less than one second intervals. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 1-15...
Page 23: Dynamic Capability
DYNAMIC mode calculating an average latitude, longitude, and altitude when there are at least four satellites in view. The factory set default number of averages is 200. These position averages are loaded into battery backed memory for future use. 1-16 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 24: Elevation Angle Mask
The system default is that set by the user. Refer to Chapter Four, paragraph titled “ENTER ELEVATION MASK ANGLE” for instruction on selecting elevation mask. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 1-17...
Page 25 Time Quality 1111 = clock failed, data unreliable. Time Quality PARITY Parity on all preceding data bits. Not Used Unassigned. Not Used Unassigned. Not Used Unassigned. Position identifier number eight. 1-18 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 26: Chapter Two Installation
The GPS Timing Unit is packaged in one shipping container. Inspect the unit for visible damage (scratches, dents, etc.). If the instrument is damaged, immediately notify both Symmetricom Inc and the responsible carrier. Keep the shipping container and packing material for the carrier’s inspection.
Page 27: Reduced Air Flow
(such as Belden 9913) must be used. Note: The GPS antenna and cable described in this manual have been replaced as described in “Appendix D: Antenna Replacement Kit” on page D-1. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 28: Primary Power Connection
Chapter One of this User’s Guide. Models ET6000 and ET6010 utilize a power cord that plugs into a Power Entry Module. Note: Check the AC line fuses located in the power entry module on the rear panel and assure the correct fuse is installed for the AC Line voltage being used to power the unit.
Page 29 If this unit is provided with a power supply other than the standard, its specifications will be found in the Option Description envelope located on the inside cover of this User’s Guide. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 30 1. Material* PVC or CPVC Schedule 80, Gray Color. Note: The GPS antenna and cable described in this manual have been replaced as described in “Appendix D: Antenna Replacement Kit” on page D-1. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 31: Gps Timing Unit Interface Connections
The RS-232 I/O interface uses a standard PC compatible one-to-one cable using nine Pin D type connectors. Handshaking is not used. Pin 6 (DSR) and pin 8 (CTS) on J12 are internally set high. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 32: Printer Output Port J11
J8 IRIG B (AC) Jumper J18 3 and4, and J28 1 and 2. J9 IRIG B (DC) Jumper J19 1 and 2, and J29 1 and 2. J10 1pps Input (Time Interval Measurement). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 33: 1Pps Input
LPRO For the TCXO, no jumpers are installed. For the OCXO, jumper pins 1-2. For the Rubidium LPRO, jumper pins 3-4. For the Rubidium X-72, jumper pins 1-2, and 3-4. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 34 INSTALLATION Figure 2-3 GPS Main Assembly 100015 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 35 Antenna Cable with Type N Connector Note: The GPS antenna and cable described in this manual have been replaced as described in “Appendix D: Antenna Replacement Kit” on page D-1. 2-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 36: Chapter Three Operation
(refer to the Main Menu Screen – this chapter). When satellites are acquired and ready for time solution, the TRACKING LED will illuminate signifying that the unit is tracking satellites. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 37 Based upon the type of internal 10MHz oscillator installed in the unit, the LOCKED LED will remain illuminated until the internal elapsed time counter has timed out. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 38: Initialization (Known Position)
Numbers” respectively). If DAC value number has approached either one of its extremes (00000 or 65535), the internal oscillator needs to be nulled/calibrated. Refer to the “Internal Oscillator Calibration” procedure in Chapter Five of this User’s Guide. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 39: Operational Characteristics
ID followed by four digits that correspond to the serial number of the unit. After approximately 5 seconds, the display then switches to the Main Menu Screen. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 40 (using the TIME INTERVAL CALIBRATION MENU screen) or inaccurate time interval measurements will result. The following is the normal MAIN MENU that is displayed. It contains the following information: Symmetricom Firmware Version. Synchronization. Time (Seconds through Days). Status and Error Messages.
Page 41 Status and error messages are displayed in Row One, starting at Column Fifteen. The status and error messages alternate every ten seconds. At initial power-up, this area will display the Symmetricom firmware version for a few seconds. ET6xxx ExacTime GPS TC & FG (Rev C)
Page 42 The number starts at the maximum number programmed (default is 200) and counts down to 0000. This message is applicable only in the AUTO MODE of operation. Refer to the paragraph titled “Number of Position Averages” for selection of number of averages. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 43 (+) or minus (-) followed by a four digit number expressed in parts to 10 or 10 (the E-exponent). Note: The GPS antenna and cable described in this manual have been replaced as described in “Appendix D: Antenna Replacement Kit” on page D-1. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 44: Position Menu Screen
Row One starting at Column thirty-three. It is a two digit value which reflects the geometry of the satellites currently being tracked. The four digit GPS week number is displayed at the start of Row Two. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 45: Set-Up Menu Screen
If more than four satellites are in view and useable, a set of four based on optimal satellite (minimum PDOP) geometry is automatically selected for use. 3-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 46 Depressing the “5” keyboard switch selects the “FLYWHEEL” mode and the “Operating Mode” changes to “FLYWHEEL.” Pressing the MENU keyboard switch returns the display to the SET-UP MENU SCREEN. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-11...
Page 47 Pressing the menu key of the keyboard while the “SET TIME” display is selected leads to a sub menu display as follows: 1>SYNC XXX XXX is UTC or GPS 3-12 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 48 GPS Reference Sphere (WGS-84). Note: If a mistake has been made while entering this data, press the MENU keyboard switch to exit, then return to this selection and reenter the data. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-13...
Page 49 (see Chapter Five). When keyboard switch 6 is pressed, it allows the user to enter a five digit DAC value, the midrange being 32767. 3-14 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 50: Rs232 I/O Configuration Menu Screen
(trigger) of this measurement. Sequentially pushing the switch produces the following: On 1 (selecting the rising edge as the on-time point) On 0 (selecting the falling edge as the on-time point) Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-15...
Page 51: Multiple Time Code Outputs Menu Screen
CHAPTER THREE 3.3.5 MULTIPLE TIME CODE OUTPUTS MENU SCREEN (MODELS ET6000 and ET6010 only) If the MENU keyboard switch is pushed again, the LCD will display the Multiple Time Code Outputs Menu Screen which is shown on below. Although this screen is displayed, it is only applicable if the TC&FG is configured and furnished with the Multiple Time Code Outputs...
Page 52: External Frequency Measurement Menu Screen
OPERATION 3.3.7 EXTERNAL FREQUENCY MEASUREMENT MENU SCREEN (MODELS ET6000 and ET6010 only) Subsequent pushing of the MENU keyboard switch will display the External Frequency Measurement Menu Screen which is shown below and contains the following choices: Column: Row 1 EXT FRQ:+0000E-14 / +0000E+00 SEC * Row 2 1>ENTER FRQ...
Page 53: Single Event Log Menu Screen
The one or zero appearing in the first and second digits is ignored in this option, therefore the contents of these digits will not be important to the unit. Pushing keyboard switch “4” starts the events log. 3-18 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 54: 50/60Hz Measurement Screen
At that point, it won’t be operational again until “LOCKED” has been achieved. This function is always available in “FLYWHEEL” mode. Operation of the 50/60Hz measurement feature is as follows: Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-19...
Page 55 Pushing the number six key of the keypad selects either 50Hz or 60Hz. 50Hz or 60Hz selection can only be done when the unit is not doing measurements. OFF is displayed in the lower right hand corner of the LCD display. 3-20 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 56: Auto Daylight Savings Menu Screen
Pushing the “1” front panel keyboard switch cycles through the output channels (1-4). Channel One controls MUX outputs on J4 and J9. Channel Two controls MUX outputs on J5 and J8. Channel Three controls MUX outputs on J6. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-21...
Page 57 Tracking output is a TTL low when not tracking and a TTL high when tracking. Locked output is a TTL low when not locked and a TTL high when locked. * Models ET6000 and ET6010 output 10KHz and 10Hz. Model ET6500 outputs 2PPS and 1PPH.
Page 58: Printer Port Configuration Menu Screen
Subsequent pushing of the MENU keyboard switch will display the Printer Port Configuration Menu Screen, which is shown below and contains these choices: Column: Row 1 PRINTER :<1> 9600<2>NONE<3>8BIT<4>1 STP Row 2 <5> STANDARD MODE Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-23...
Page 59 M0 - mode (start-up mode) * S00 = status code (doing GPS corrections) * E00 = error code (system check OK) 25 00 00 00 = tracking satellite vehicle 25 3-24 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 60 The on-time point is at the beginning of the Carriage Return character. Quality Indicator: This indicator is an estimation of the accuracy of the unit’s 1PPS compared to the GPS system 1PPS. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-25...
Page 61: Ieee-488 I/O Interface Menu Screen
< 100 microseconds < 1 millisecond > 1 millisecond (unknown) 3.3.13 IEEE-488 I/O INTERFACE MENU SCREEN (MODELS ET6000 AND ET6010 ONLY) If the keyboard switch is pushed again, the LCD will display the IEEE-488 I/O Interface Menu Screen, which is shown below. Although this screen is displayed, it is only applicable if the TC&FG is configured and furnished with the IEEE-488 I/O Interface option, GPS Opt 14...
Page 62 1 and 2 shorted pins 5 and 6 shorted 10MHz sine wave output pins 1 and 2 shorted pins 7 and 8 shorted unused pins 3 and 4 shorted Event 2 input Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 3-27...
Page 63 CHAPTER THREE This Page Intentionally Left Blank 3-28 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 64: Chapter Four I/O Port Data Input/Output
Table 4-1 shows the command options available. The ASCII character is shown following its HEX equivalent. Following the table, each command is described with the necessary steps for execution. Table 4-1 is located on the following page. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 65 *External Frequency Measurement – Select Input Frequency *External Frequency Measurement – Enable/Disable *External Frequency Measurement – Request Data * Models ET6000 and ET6010 only. The remainder of Table 4-1 is continued on the following page. ET6xxx ExacTime GPS TC & FG (Rev C)
Page 66: Symmetricom Firmware Version
** Optional. Refer to the Option Description in Appendix C. SYMMETRICOM FIRMWARE VERSION This command outputs the Symmetricom firmware version installed in the unit. • The user inputs $`(HEX 24/HEX 60). • The unit will respond with eight characters followed by CR/LF.
Page 67: Utc Sync
Codes are shown in Table 4-2 and the Error Codes are shown in Table 4-3. Table 4-2 Status Codes Characters Definition Doing GPS Correction. GPS time not acquired. Waiting for almanac. Unit stabilizing. Table 4-2 continued on next page. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 68 The unit is doing GPS corrections. The system check is OK. The unit is tracking satellites 3, 13, 20, and 26. • If the user inputs $ = (HEX 24/HEX 3D). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 69: Print Position
2 digits of degrees latitude (space). 2 digits of minutes latitude. 4 digits of ten thousandths of minutes latitude. N or S (space). 3 digits of degrees longitude (space). 2 digits of minutes longitude. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 70: Clear Event Data
If that happens, the fact that an event has been missed will be reported in the event status. Table 4-4 shows the possible event status codes. Table 4-4 Event Status Codes Code Definition Normal. Missed event Channel One. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 71: Request One Event Log Data
Where: bb = event status aaa = requested event number xx = event channel number ddd = days hh = hours mm = minutes ss = seconds cc = subseconds ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 72: Enable Single Event Log
This command allows the user to select the mode of operation. This one digit command indicates the following modes: 0 = AUTO Mode. 1 = Stationary Mode (Timing Mode). 4 = Dynamic. 5 = Flywheel Mode. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 73: Enable Time Interval
• The user inputs $u (HEX 24/HEX 75). • The unit responds with 134276.512 CR/LF. 4-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 74: Request Elevation Mask Angle
• The unit responds with OK CR/LF. 4.19 DISABLE DISCIPLINING This command allows the user to disable the discipline feature. • The user inputs $ { (HEX 24/HEX 7B). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-11...
Page 75: Enter Position
Four digits of altitude in meters. • • The user inputs $ } (HEX 24/HEX 7D) 3348824N11753397W+0026 • The unit responds with OK CR/LF. The above example is entering Symmetricom’s position of: Latitude 33 48.824 N. Longitude 117 53.397 W.
Page 76: Request Dac Value
• The user inputs $| (HEX 24/HEX 7C) 07.0. • The unit responds with OK CR/LF. The above example (07.0) inputs a local time offset to correspond to daylight savings time in the Pacific Time Zone. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-13...
Page 77: Enter Cable Delay
GPS on-time 1pps pulse. This command must be issued if the antenna cable length is changed and subsequently a new cable delay is entered. • The user inputs $W (HEX 24/HEX 57). • The unit responds with OK CR/LF. 4-14 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 78: Select Default Values
Leading zeros are required to be entered. • The unit responds with OK CR/LF. Example: $Y01000000 CR/LF The above example illustrates selecting an input frequency of 1MHz. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-15...
Page 79: External Frequency Measurement - Enable/Disable
SNR. This format will be printed for each satellite in view. If the signal SNR is 0.00, the satellite has not been acquired. The last satellite’s information will be followed by CR/LF. 4-16 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 80: Request Unit Operating Parameters
The address (17) of the IEEE-488 interface. This number will be meaningful only if the option is installed. 1 = Unit Locked 0 = Unit Unlocked The last response is CR/LF. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-17...
Page 81: 50/60Hz Selection
$D 023.406 The above example illustrates entering a time error offset of –20.346 seconds. Note: The time error offset can only be entered if the 50/60Hz measurement option is OFF. 4-18 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 82: Request 50/60Hz Measurement Data
This command allows the user to set-up the printer configuration. It is applicable to both the Standard RS232 Printer Output and the One Second Burst RS232 ASCII Time Output. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-19...
Page 83: Printer - Request Configuration
This command allows the user to specify the printer mode or output format . The selection is either “Standard” or “One Second Burst”. For a detailed description of these two formats, refer to Chapter Three – Operation. 4-20 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 84: Printer - Select Output Rate
PRINTER – ENABLE/DISABLE & DATA SELECT This command is applicable only to the Standard RS232 Printer Output. • User inputs $n (HEX 24/HEX 6E) followed by three (3) digits. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-21...
Page 85 94 027.17:04:43 M0 S00 E00 25 00 00 00 -0019-E12 33 48.8270N 117 53.3864W +0028 T1 705337.512 94 027.17:04:48 M0 S00 E00 25 00 00 00 -0019-E12 33 48.8270N 117 53.3864W +0028 T1 705337.512 4-22 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 86: Enter Preset Coincidence Time
300 nanoseconds (or 3 tenths of a microsecond). The preset coincidence pulse occurs 200 nanoseconds late. It’s pulse width is approximately two microseconds wide, positive edge on-time. It is capable of driving ten LSTTL loads. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-23...
Page 87: Request Mux Output
1pps DC Code * 10KHz is output in Models ET6000 and ET6010. 2PPH is output in Model ET6500. ** 10Hz is output in Models ET6000 and ET6010. 1PPH is output in Model ET6500. See Chapter One of this User’s Guide for specifications.
Page 88: Set Mux Output
2 characters representing year. • The user enters $< (HEX 24/HEX 3C) followed by two digits. • The unit responds with OK CR/LF. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-25...
Page 89: Automatic Daylight Savings Time
This command allows the following daylight savings time intervals to be loaded into memory. If you want the unit to automatically increment/decrement, the following command must be proceeded by the ENABLE command. • The user inputs F (HEX 46). 4-26 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 90: Request Auto Daylight Savings Time Interval
If the stop time is less than the start time, then the stop time is assumed to be in the next year. Performing a “Cold Reset” will disable the Daylight Savings time feature and load in the ten default time intervals. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) 4-27...
Page 91: Request Unit Serial Number
This command allows the user to request the unit’s serial number (the same serial number that is on the rear panel). • The user inputs $@ (HEX 24/HEX 40). • The unit will respond with four characters followed by CR/LF. 4-28 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 92: Chapter Five Maintenance/Troubleshooting
2. Sync one trace of an oscilloscope on the known frequency standard. Using the other trace, monitor the 10MHz output of the unit. Remove the top cover of the unit. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 93 If a known frequency standard is not available, the oscillator may be nulled as follows: 1. Set the unit to operate in the STATIONARY mode. Wait until the unit is LOCKED. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 94: Lcd Adjustment
The duty cycle (symmetry) of the 10MHz square wave output can be adjusted to approximate 50/50% using potentiometer R60. When making this adjustment, monitor the 10MHz square wave at the rear panel BNC output. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 95: Troubleshooting
5.2.3 TRACKING LED DOES NOT ILLUMINATE • Antenna/preamp is defective. • Cable or connections between the antenna/preamp and the unit are open or intermittent. • OnCore GPS Module (55182) is defective. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 96: Locked Led Does Not Illuminate
Note: If new software has been installed in the unit, a cold reset will automatically be performed the first time power is applied. The following message will appear on the LCD for approximately four seconds: COLD RESET DONE, UNIT SET TO DEFAULT Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 97: Theory Of Operation
No correction to the time or frequency are done by the unit, it simply continues from the last information in terms of the DAC value, position data, output selection, etc. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 98 Stationary mode, load the average position into the receiver, set time and begin normal Stationary mode of operation. We will discuss this normal mode of operation in more detail later. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 99: Exactime Internal Configuration
This board provides the mounting for the LCD display as well. The LCD provides all of the operator information, menu selections, and operator feedback of entries. The interface is through two multi-pin ribbon cables to the Main Assembly. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 100: Microcomputer Program Theory Of Operation
When the unit turns on the LOCK LED, the current BIAS information is measured again and the difference (after much filtering) is used to control the frequency of the internal oscillator. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 101 “disciplined” to the GPS reference information. Both the integration (filtering) of the information in the computer as well as the oscillator stability form a very stable system especially when the oscillator is a rubidium oscillator. 5-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 102 3 Bad LCD Change LCD with a known good one. 4 LCD Drivers Bad Change 100015 main board with a known good one. (Contact Symmetricom for repair). 1 Bad Oncore (GPS Receiver Swap Oncore with a known good one. Time Does Not...
Page 103 Interface Cable Not Check cable 812515-3 for proper seating. Push Buttons Don’t Work Connected Bad Switch Swap front panel assembly with a known good one. (Contact Symmetricom for repair). 5-12 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 104 MAINTENANCE/TROUBLESHOOTING Figure 5-1 ET6000 Block Diagram LCD Front Panel Front Panel Display Keypad 100015 Main Assembly PRINTER PORT 1PPS INPUT IRIG B 1PPS (ref) (DC) Receiver RS-422 I/O IRIG B (AC) Buffer and I/O 10MHz Microprocessor Interface Clock 1PPS LOCKED...
Page 105 CHAPTER FIVE This Page Intentionally Left Blank 5-14 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 106: Part One
ETB (^W) CAN (^X) EM (^Y) SUB (^Z) ESC (^[ ) FS (^ \ ) GS (^ ] ) RS (^^) US (^_ ) Note: First ^ denotes the Control Key. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 107: Part Two
APPENDIX A ASCII Character Code Table Part Two CHAR ” & ’ < > ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 108: Part Three
ASCII CHARACTER CODE TABLE ASCII Character Code Table Part Three CHAR Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 109: Part Four
APPENDIX A ASCII Character Code Table Part Four CHAR ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 110 APPOS Approximate Position. ASCII American Standard Code for Information Interchange. Azimuth The angle for true North of the horizontal projection of the line of sight vector measured clockwise. Azimuth. Symmetricom Inc ET6xxx ExacTime GPS TC&FG (Rev C)
Page 111 The difference between the clock’s indicated time and true universal time. Control Segment A world-wide network of GPS monitoring and control stations that ensure the accuracy satellite positions and their clocks. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 112 Data Terminal Equipment (See RS-232-C). - E - ECEF Earth Centered - Earth Fixed. Electronic Industries Association. Elevation Angle The angle between the line of sight vector and the horizontal plane. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 113 Greenwich Mean Time. GMT Offset/Local Time Offset An example of the difference between local time and GMT time is: EST (Eastern Standard Time) minus GMT time is five hours. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 114 (latitude and longitude) and the vertical position (altitude). For 2-D position fixes HDOP is all that counts. - I - Interface Control Document. Identification. Interface. Input/Output. Ionosphere/Ionospheric. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 115 The primary L-Band signal radiated by each NAVSTAR satellite at 1575.42 MHz. The L1 beacon is modulated with the C/A and P codes with the NAV message. L2 is centered at 1227.60. Latitude. Longitude. Least Significant Bit. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 116 This information is used to process GPS signals to obtain the users position and velocity. NAVSTAR The name given to GPS satellites. NIST National Institute of Standards Technology. ns/nsec Nanosecond. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 117 Pseudo-range differs from actual range because the satellite and user clocks are offset from GPS system time by propagation delays and other errors. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 118 When implemented, it is the largest source of error in the GPS system. Schedule. Spherical Error Probable. Standard Positioning Service. The normal civilian positioning accuracy obtained by using the single frequency C/A code. Space Segment. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 119 Universal Time Coordinated. The time standard maintained by the U.S. Naval Observatory. GPS Time is directly related to UTC time. - V - No glossary terms have been defined for “V.” B-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 120 No glossary terms have been defined for “X.” - Y - No glossary terms have been defined for “Y.” - Z - No glossary terms have been defined for “Z.” Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) B-11...
Page 121 APPENDIX B This Page Intentionally Left Blank. B-12 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 122: Three Channel Encoder
Note: Changing the Code Output selection may change the output amplitude. See Table 01-2 for amplitude and modulation ratio controls. 1.2.1 OUTPUT AMPLITUDE (MODULATED) Nominal 3 volts peak-to-peak into a 50Ω load (adjustable) 1.2.2 MODULATION RATIO Nominal 3:1, adjustable from 2:1 to 6:1 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 123 BNC connector J3a or J3d. Refer to the GPS Option/Connector Configuration Sheet in the User’s Guide. If a cold reset was performed and the Three Channel Encoder was not programmed afterwards, all three Channels will output IRIG B. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 124 Closed IRIG E112 Open Closed Open Closed IRIG H122 Closed Open Open Closed Closed Closed Closed Open 2137 Closed Closed Closed Open NASA 36 Open Closed Closed Open Binary Weight Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C)
Page 125 (BNC J5) (BNC J6) Modulation Ratio Amplitude Detailed definitions and specifications for each of the time codes that are generated by the Three Channel Encoder are provided on the following pages. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 126 Occurs first, except for fractional seconds information, which occurs following the day-of-year information. Element Rates Available • 1000 per second (basic element rate). • 100 per second (POSITION IDENTIFIER rate). • 10 per second (frame rate). Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C)
Page 127 IDENTIFIER ELEMENTS (seven for seconds, seven for minutes, six for hours, ten for days) until the CODE WORD is complete. A POSITION IDENTIFIER occurs between decimal digits in each group to provide separation for visual resolution. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 128 Binary One = 50 µS Binary Zero = 20 µS Reference = 80 µS Time Frame = 0.01 Second 0.01 Sec Control Functions P0 PR 100µS (Element Rate = 10 KPPS) Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C)
Page 129 (The “on-time” point, to which the CODE WORD refers, is the leading edge of the second POSITION IDENTIFIER.) Resolution 0.10 milliseconds (unmodulated): 0.01 millisecond (modulated). Carrier Frequency 100kHz when modulated. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 130 • REFERENCE MARKER: One per 10 seconds. Two consecutive POSITION IDENTIFIERS. (The “on-time” point, to which the CODE WORD refers, is the leading edge of the second POSITION IDENTIFIER.) Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C)
Page 131 • “On-Time” reference point for each element is its leading edge. • INDEX MARKER duration: 0.2 seconds. (Binary Zero or uncoded Element.) • CODE DIGIT duration: 0.5 seconds. (Binary One.) C-10 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 132 • 25 per second (basic element rate). Four consecutive pulses missing at the end of the frame. • One per second (frame rate). Element Identification • “On-Time” reference point for each element is its trailing edge. • Binary zero duration: 12 milliseconds. Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-11...
Page 133 • 25 per second (basic element rate). Four consecutive pulses missing at the end of the frame. • One per second (frame rate). Element Identification • “On-Time” reference point for each element is its trailing edge. • Binary zero duration: 12 milliseconds. C-12 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 134 DIGIT occurs between decimal digits in each group to provide separation for visual resolution. Least Significant Digit Occurs first. Element Rates Available • 100 per second (basic element rate). • One per second (frame rate). Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-13...
Page 135 INDEX MARKER. (The “on-time” point, to which the CODE WORD refers, is the leading edge of the INDEX MARKER following the four POSITION IDENTIFIERS.) Resolution 10 milliseconds (unmodulated). One millisecond (modulated). Carrier Frequency 1kHz when modulated. C-14 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 136 OPTION DESCRIPTIONS ASSEMBLY 55116 Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-15...
Page 137: Mhz Sine Wave Shaper
50Ω load. OUTPUT AMPLITUDE ADJUSTMENT The output amplitude of this signal can be adjusted to the desired amplitude using LEVEL potentiometer R13, on the Sine Wave Shaper assembly. C-16 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 138: Mhz Sine Wave Shaper
50Ω load. OUTPUT AMPLITUDE ADJUSTMENT The output amplitude of this signal can be adjusted to the desired amplitude using LEVEL potentiometer R13, on the Sine Wave Shaper assembly. Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-17...
Page 139: Vdc Dual Power Input
TC&FG. Internal Fuses: F1 protects DC input from connector J1A. F2 protects DC input from connector J1B. Fuses are 4 amp, slow blow, 5x20 millimeters (located on Assembly 100002). C-18 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 140 DC Input 1 Return (Signal Ground) Input 2 J1B pin 1 DC Input 2 J1B pin 2 Chassis Ground J1B pin 3 DC Input 2 Return (Signal Ground) Pin 1 Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-19...
Page 141 APPENDIX C ASSEMBLY 100002 C-20 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 142: Vdc Power Supply
25watts Internal Fuses: F1 protects DC input from Input A. F2 protects DC input from Input B. Fuses are 1 amp, fast blow, 5x20 millimeters (located on Assembly 55193). Symmetricom Inc ET6 ExacTime GPS TC & FG (Rev C) C-21...
Page 143 TEMPERATURE The operating temperature of the unit should not exceed +40°C. This limitation is due to the fact that there is no forced air flow over the DC-DC converter. C-22 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 144: Vdc Power Supply
Timing Relay - Normally Closed Contact TB1-8 50/60Hz Measurement Input - HI TB1-9 50/60Hz Measurement Input - LO TB1-10 DC In 2 (optional) TB1-11 DC In 2 Return (optional) TB1-12 Chassis Ground (optional) Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-23...
Page 145 1pps pulses from the GPS receiver. The phase angle measurement is made by calculating where the 1pps pulse occurs in relationship to the 50/60Hz sine wave. C-24 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 146 This command allows the user to enable or disable the 50/60Hz measurement feature. • The user inputs $B (HEX 24, HEX 42) followed by either a zero or a one. Zero turns the option OFF, and one turns the option ON. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-25...
Page 147 CR/LF. Example: 60.1324Hz + 1.357SEC 180.2DEG + 1.206 OFFSET CR/LF The above response states that the frequency measurement is 60.1324Hz, and the accumulated time error is +1.206 seconds. C-26 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 148 (such as a noise spike), the measurement is ignored, and an error is counted. If 1,000 successive errors are read, the message ERR appears, and the 60Hz measurement option is turned OFF. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-27...
Page 149: Low Phase Noise Oscillator
There are two methods to null/calibrate the internal oscillator. CALIBRATION - FIRST METHOD The oscillator can be nulled against a known frequency standard with an oscilloscope or other suitable means by using the following steps: C-28 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 150 If the DAC value is 65535, turn the oscillator adjustment counterclockwise which will decrease the frequency and the DAC value. If the DAC value is 00000, turn the oscillator adjustment clockwise which will increase the frequency and the DAC value. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-29...
Page 151 7. Install the screw in the oscillator adjustment access hole. 8. If after approximately one hour, the DAC value has changed by more than ±5,000 from 32767, repeat steps one through six. C-30 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 152: Parallel Bcd Output (Days – Milliseconds)
Two sample time pulses are provided in the connector J3B. One sample time pulse is at the least significant bit (LSB) rate: Connector J3B Pin 38 is 1pps (STP 1P). Connector J3B Pin 48 is 1kpps (STP 1K). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-31...
Page 153 The three selectable pulse rates can be programmed from the front panel using the keypad. Cycle through the various menu screens using the MENU switch until the PULSE RATES screen appears. • Sequentially pushing keyboard Switch One will cycle through the three channels. C-32 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 154 The user enters $G (HEX 24/HEX 47). Channel (output) number Space Four digits of pulse rate followed by pps space (the above is repeated for each channel followed by CR/LF). Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-33...
Page 155 Rear Panel Connector Pin Assignments Signal Signal D100 mS10 D200 mS20 mS40 ST1P mS80 mS100 mS200 UNLOCKED mS400 mS800 ST1K * True when unit is unlocked. Low when unit is locked. C-34 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 156 OPTION DESCRIPTIONS ASSEMBLY 55128 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-35...
Page 157: Ieee-488 I/O Interface
Address can also be selected via the RS-232 I/O port. The user inputs $CXX. (The XX corresponds to a two digit device address number). The unit will respond with OK CR/LF (carriage return/line feed). C-36 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 158 MLA (my listen address containing the address of the controller) TAG (talker address group containing the address of our interface). Our interface will always respond with specific data followed by CR/LF. MAINTENANCE No routine maintenance is required. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-37...
Page 159 APPENDIX C Table One IEEE-488 Bus Interface Connector Pin Assignment J13 Pin Signal D101 D102 D103 D104 NRFD NDAC D105 D106 D107 D108 C-38 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 160 OPTION DESCRIPTIONS Table Two Applicable Command/Character ID ASCII Description Format/ Char Char Response Symmetricom Firmware Version User’s Guide UTC Sync User’s Guide GPS Sync User’s Guide Print Frequency Offset User’s Guide Print Time, Status, Error Code and Satellite Vehicle User’s Guide...
Page 161 Note 3: 115VAC/125VDC Power Supply with 50/60Hz Measurement Option, Option 08AE must be installed. See GPS Option Description 08AE. Note 4: External Frequency Measurement Option, Option 02 must be installed. See GPS Option Description 02. C-40 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 162 OPTION DESCRIPTIONS ASSEMBLY 55115 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-41...
Page 163 Operating Temperature: C Base Plate to +70 C Base Plate Storage Temperature: C to +85 Altitude: -200 feet to +20,000 feet Trim Range: > +1 x 10 C-42 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 164 • Disable disciplining. Refer to Chapter Four, “Disable Disciplining” in the User’s Guide. Set the DAC value to it’s midpoint 32767. Refer to Chapter Four ,“Enter DAC Value” in the User’s Guide. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-43...
Page 165 Keep adjusting the oscillator in the appropriate direction until the DAC value is approximately at its midpoint (32767). If after approximately one hour, the DAC value has changed by more than ±5,000 from 32767, repeat steps one through six. C-44 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 166 FREQ CTRL VSS (Power and Signal Return) 1PPS IN 1PPS OUT LOCK (if low, Rb oscillator locked) FXQ (VCXO freq. output) FACMOS RTN FACMOS OUT FSINE RTN FSINE OUT Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-45...
Page 167 5 minutes to lock (accuracy @ lock ≤ 5 x 10 Warm-up Time: 7.5 minutes (accuracy ≤ 1 x 10 The following specifications apply to the Selected 10 MHz Output (from the ET6000 etc.) at a 13dbm output level: Harmonics:...
Page 168: Mhz Sine Wave Shaper
50Ω load. OUTPUT AMPLITUDE ADJUSTMENT The output amplitude of this signal can be adjusted to the desired amplitude using LEVEL potentiometer R13, on the Sine Wave Shaper assembly. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-47...
Page 169 1565 to 1586 MHz Return Loss > 20dB from 1565 to 1586 MHz Insertion Loss < 0.5 dB from 1565 to 1585 MHz 50 Ω Impedance Connector Type N C-48 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 170 • When connecting the cable from the antenna to the Lightning Arrestor, install a drip loop before it enters the arrestor. This keeps any large amounts of moisture from coming down the cable and collecting at the connector, causing a loss and/or failure. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-49...
Page 171 Arrestor. Also, do not install or inspect the Lightning Arrestor during an electrical storm. When connecting the Lightning Arrestor or when changing the gas capsule arrestor, make sure that the connecting equipment and components are disconnected or switched off. C-50 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 172 To Antenna Access to Non-radioactive Gas Capsule Arrestor 73 Z-0-0-448 Ground Terminal 1/4" Outside Copper Ground Strap Lightning Arrestor (Customer Furnished) 3403.17.0016 Ground Terminal 1/4" Mounting Plate Inside (Customer Furnished) Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-51...
Page 173 ANTENNA 1.122 2.5129 (28.5) (64) 2.1654 (55) EQUIPMENT 0.3346 Clearance Hole Mounting Hole (8.5) On Mounting 0.1732 Max. Plate (4.4) NOTE 0.625 Number in ( ) is Millimeters (16) C-52 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 174: Signal Distribution
All other modules input selection is similar. Out1, Out 2, Spare 1, Spare 2, and Spare 3 can be optionally jumpered to other signals dependent on customer requirements. PD6 and PD7 are software controlled optional signals. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-53...
Page 175 This pulse buffer plug in module outputs a 0 to +10 volt positive going signal. Dash numbers determine the input on-time edge selection and pulse width. Example: 35000-110 Triggers on input negative/falling edge. 20µs pulse width. 35000-210 Triggers on input positive/rising edge. 20µs pulse width. C-54 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 176 OPTION DESCRIPTIONS ASSEMBLY 55143 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-55...
Page 177: Mhz Square Wave Output
The square wave is output only while the unit is in the LOCK mode S3 open/up The square wave will be output regardless of whether the unit is locked or not. C-56 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 178 The DS1 signal is switch selectable to provide various features. (See Table One below). • Down is the closed (0) position. • Up is the open (1) position. • Switch 1-1 selects between T1 and E1 functions. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-57...
Page 179 533 - 655 Feet DSX - Cross Connect * The normal, as shipped position of each switch. Table Three is a list of specifications applicable to GPS Option 33B (T1 Assembly 55155) C-58 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 180 Multi-frame Multi-frame Frame Bits 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FDL bits are all zeros. Appropriate CRC check sums are generated. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-59...
Page 181 The CEPT signal is switch selectable to provide various features. (See Table Four). • Down is the closed (0) position. • Up is the open (1) position. • Switch 1-1 selects between T1 and E1 functions. C-60 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 182 *AMI Coding HDB3 Coding T1 Output *E1 Output *Disable CRC4 Multi-frame Enable CRC4 Multi-frame Enable CAS Multi-frame *Disable CAS Multi-frame * The normal, as shipped position of each switch. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-61...
Page 183 CEPT Format (Sixteen Frames/Multi-Frame) Multi-Frame Multi-Frame 10 11 12 13 14 15 Frame Number Table Five is a list of specifications applicable to GPS Option 33C (E1 Assembly 55155-1). C-62 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 184 CEPT Signal Type CEPT, Balanced Frequency 2.048 MHz Format Framed All 1’s Jitter <0.05 U.I. Connector See Note Note: See the GPS Option/Connector Sheet in the ExacTime User’s Guide. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-63...
Page 185 APPENDIX C ASSEMBLY 55155 C-64 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 186 Alarm Relay Normally Open Contact. Alarm Relay Common Contact. Alarm Relay Normally Closed Contact. Not Used. SYNC Input. Sync Input Return. 8kHz TTL Output. GND. 1.544MHz TTL Clock Output Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-65...
Page 187 See Table Two below. See Table Two below. *Inhibit Bit 7 Stuffing. Enable Bit 7 Stuffing. Inhibit B8ZS Enable B8ZS * The normal, as shipped position of each switch. C-66 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 188 TTL compatible, active low Frequency 8 kHz or sub-multiple of 8 kHz Connector See Note Monitor Summary Alarm Contact Closure Contact Rating 2 A at 30 V dc (maximum) Connector See Note Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-67...
Page 189 Multi-frame Multi-frame Frame Bits 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FDL bits are all zeros. Appropriate CRC check sums are generated. C-68 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 190 All three of these optional outputs are frequency locked to an internal 10MHz reference. The CEPT signal is switch selectable to provide various features. (See Table Four). • Down is the closed (0) position. • Up is the open (1) position. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-69...
Page 191 *AMI Coding HDB3 Coding T1 Output *E1 Output *Disable CRC4 Multi-frame Enable CRC4 Multi-frame Enable CAS Multi-frame *Disable CAS Multi-frame * The normal, as shipped position of each switch. C-70 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 192 Monitor Summary Alarm Contact Closure Contact Rating 2 A at 30 V dc (maximum) Connector See Note Note: See the GPS Option/Connector Configuration Sheet in the ExacTime User’s Guide. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-71...
Page 193 30 31 CEPT Format (Sixteen Frames/Multi-Frame) Multi-Frame Multi-Frame 10 11 12 13 14 15 Frame Number Note: For a top assembly view of this module, see the previous section C-72 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 194 Each of the above outputs is provided via a 250 milliampere high speed buffer/driver. The gain of the buffer is 1:1 so the output amplitude is dependent on the input and the load. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 195 APPENDIX C For GPS Option 40P, the signal connections provided at J2 of the 35007 Motherboard Assembly are as follows: J2 PIN SIGNAL LOCK\ TRK\ OUT5 OUT6 EXTFREQ VDD (+5) C-74 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 196 The above output is provided via a 250 milliamphere high speed buffer/driver. The gain of the buffer is 1:1 so the output amplitude is dependant upon the input and the load. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 197 APPENDIX C For GPS Option 40AP, the signal connections provided at J2 of the 35007 Motherboard Assembly are as follows: J2 PIN SIGNAL LOCK\ TRK\ OUT5 OUT6 EXTFREQ VDD (+5) C-76 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 198 BNC are J19/J23 and J18/J22. Rear Panel Output Connector designations and signal characteristics are described in the GPS Option/Connector Configuration sheet located at the front of the ExacTime User’s Guide. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-77...
Page 199 1:1 so the output amplitude is dependent on the input and the load. For GPS Option 40BP, the signal connections provided at J2 of the 35007 Motherboard Assembly are as follows: J2 PIN SIGNAL LOCK\ TRK\ OUT5 OUT6 EXTFREQ VDD (+5) C-78 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 200: Pulse Rate Module
Note 2: The specific Motherboard BNC designation is dependant on which Motherboard option area the Pulse Rate Module is installed. Refer to the GPS Option/Connector Configuration sheet in the ExacTime User’s Guide for connector designations and locations. Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-79...
Page 201 Open Open Open 240PPS Open Open Open Open Open 500PPS OUTPUT SPECIFICATIONS Form Factor: Square Wave (50/50% duty cycle). On-Time Edge: Rising edge. Characteristics: TTL levels into 50 ohms. C-80 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 202 OPTION DESCRIPTIONS ASSEMBLY 100001 Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C) C-81...
Page 203 APPENDIX C This Page Intentionally Left Blank C-82 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 204: Antenna Replacement Kit
• For cable runs longer than 300 feet, an optional GPS Down/Up Converter kit is available Other GPS Antenna Options: • A Lightning Arrestor kit • A 1:2 splitter (distributes the signal from a single antenna to two GPS receivers) Symmetricom Inc ET6xxx ExacTime GPS TC & FG (Rev C)
Page 205 APPENDIX D This Page Intentionally Left Blank. ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc...
Page 206 SYMMETRICOM TIMING & TEST For more information about the complete range of Quality MEASUREMENT Timing Products from the Symmetricom group of companies 3750 Westwind Blvd. call 1-800-544-0233 in the US and Canada. Santa Rosa, California 95403 USA Tel: 707-528-1230 Or visit our site on the world wide web at Fax: 707-527-6640 http://www.Symmetricom.com...

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Et6500-tcxo Et6500-ocxo Et6010 Et6500-rb1

Symmetricom ET6000 User Manual

1 Introduction

Chapter One General Information

2 Introduction

Chapter Two Installation

3 Introduction

Chapter Three Operation

4 Introduction

Chapter Four I/O Port Data Input/Output

5 Maintenance

Chapter Five Maintenance/Troubleshooting

Appendix A

APPENDIX C Three Channel Encoder

Appendix D

Antenna Replacement Kit

Quick Links

Troubleshooting

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