Symmetricom ATS-6501 Tflex User manual

DOC06501_Revision F
ATS-6501 Users Guide
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ATS-6501 Tflex
GPS Time & Frequency Standard
Users Guide
Revision F
For Software Version 3.6.X
MAR 2010

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DOC06501Rev F
Revision History
Revision Description Date Approved
A Initial release 02/10/09
B Command updates 05/23/09 GAR
C Add 4395A-5, NASA 36 10/02/09 GAR
D Added support contact
information
11/10/09 GAR
E Add 4372A, DC power
correction
2/24/10 GAR
F Add C of C 3/29/10 GAR

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Table of Contents
1General Information ............................................................................................. 1
1.1Introduction .......................................................................................................... 1
1.2Ordering Information ........................................................................................... 1
2Installation............................................................................................................ 3
2.1Powering on the ATS-6501.................................................................................. 3
2.2Communicating with the ATS-6501 .................................................................... 4
2.2.1DHCP............................................................................................................ 4
2.2.2Static IP Addresses ....................................................................................... 4
2.2.2.1Network..................................................................................................... 4
2.2.2.2Console Cable ........................................................................................... 4
2.2.3Setting a Static IP Address............................................................................ 5
2.2.4USB Ports...................................................................................................... 5
2.3Antenna Installation ............................................................................................. 6
2.3.1Antenna Location.......................................................................................... 6
2.3.2Setting the Antenna Voltage ......................................................................... 8
2.3.3Outdoor Antenna Grounding ........................................................................ 9
2.3.4Antenna Mask Angle .................................................................................... 9
2.3.5Positioning Modes ...................................................................................... 10
2.3.5.1Dynamic Position Mode.......................................................................... 10
2.3.5.2Auto Position Mode ................................................................................ 10
2.3.5.3Manual Position Mode ............................................................................ 12
2.4ATS-6501 Installation ........................................................................................ 13
2.4.1Power Supplies............................................................................................ 13
2.4.2Output Cards ............................................................................................... 13
2.4.2.1 4394A (PPS/DC IRIG) ................................................................................ 14
2.4.2.2 4395A-10 (10MHz) / 4395A-5 (5MHz) ...................................................... 16
2.4.2.3 4387A (Modulated IRIG/NASA36) ............................................................ 16
2.4.2.4 4372A Fiber output module ......................................................................... 17
2.4Antenna Delay Calibration................................................................................. 18
2.5On Time Point (OTP)......................................................................................... 19
2.6Using an External Frequency Reference:........................................................... 19
2.7Saving User Configuration Files ........................................................................ 21
2.7.1User Configuration Files............................................................................. 21
2.7.2FTP and Real-Time (rt) Configuration Files .............................................. 22
3Operations .......................................................................................................... 25
3.1Front Panel ......................................................................................................... 25
3.1.1 Power Supply Indicators .................................................................................. 25
3.1.2Alarm Indicator........................................................................................... 25
3.1.3Oscillator Locked (Osc Lock) Indicator ..................................................... 26
3.1.4GPS Tracking Indicator .............................................................................. 26
3.1.4NTP Locked Indicator................................................................................. 27
3.1.5.Outputs Enabled Indicator .......................................................................... 27

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3.1.6.Fans ............................................................................................................. 27
3.1.7.Flash Card ................................................................................................... 28
3.1.8.Display Button ............................................................................................ 28
3.2Rear Panel .......................................................................................................... 28
3.3Software ............................................................................................................. 29
3.3.1Current Version........................................................................................... 29
3.3.2Software Updates ........................................................................................ 30
3.3.2.1Flash Card Replacement.......................................................................... 30
3.3.2.2Remote Software Update ........................................................................ 30
3.3.3GPS Firmware Updates............................................................................... 31
3.3.4Declassifying the System............................................................................ 31
3.4User Interfaces.................................................................................................... 32
3.4.1Operating System........................................................................................ 32
3.4.2Telnet .......................................................................................................... 32
3.4.3.1Real Time Data Port (1135) .................................................................... 32
3.4.3.2Command Port (1700)............................................................................. 32
3.4.3.3 Diagnostic Port (1800)................................................................................. 34
3.4.3.4Status Port (1900).................................................................................... 35
3.4.4File Transfer Protocol (FTP)....................................................................... 35
3.4.5Network Time Protocol (NTP) ................................................................... 35
3.5Status Command ................................................................................................ 36
3.6Data Logging...................................................................................................... 36
3.6.1FTP Data Logging....................................................................................... 37
3.6.2Real Time Data Logging............................................................................. 39
3.7WAAS Satellites ................................................................................................ 41
3.8.System Verification............................................................................................ 41
4Theory of Operations ......................................................................................... 49
4.1Generation of Timing Signals ............................................................................ 49
4.2Log Collection.................................................................................................... 50
4.3Startup Sequence ................................................................................................ 50
5Maintenance ....................................................................................................... 52
5.1 Internal Inspection .................................................................................................. 52
5.2 Antenna and Antenna Cable Inspection.................................................................. 52
5.3 Fan Filter................................................................................................................. 53
6.Troubleshooting ................................................................................................. 54
6.1Front Panel Indications....................................................................................... 54
6.2Alarm Light ........................................................................................................ 54
6.2.1Power Supplies............................................................................................ 54
6.2.2Outputs Enabled.......................................................................................... 55
6.2.3GPS Performance........................................................................................ 56
6.2.3.1Poor GPS Receiver Performance ............................................................ 56
6.2.3.2GPS Not Tracking ................................................................................... 57
6.2.4Internal Clocks ............................................................................................ 59
6.2.5External Reference...................................................................................... 59

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6.2.6NTP Server.................................................................................................. 61
6.2.7.PTD Value is Noisy .................................................................................... 61
6.2.8Over Temperature and Fans........................................................................ 62
6.2.9PPS Outputs ................................................................................................ 62
6.2.10 IRIG Outputs.................................................................................................. 63
6.2.11 NASA36 Outputs ........................................................................................... 64
6.3Communication Problems .................................................................................. 65
6.3.1LAN ............................................................................................................ 65
6.3.2Console (Command Port) ........................................................................... 65
6.3.3External Reference...................................................................................... 65
6.4Syslog Error Command...................................................................................... 66
Appendix A System Specifications ................................................................................. 67
Appendix B Status Command Fields............................................................................... 71
Appendix C Status Port (1900) Example......................................................................... 75
Appendix D Detailed Command Information ................................................................. 80
Appendix E Julian Date Calendars .................................................................................. 98
Appendix F Certificate of Compliance.......................................................................... 100
Figures
Figure 1 Antenna Location. ................................................................................................ 6
Figure 2Antenna Cable ....................................................................................................... 8
Figure 3 Rear Panel Output Card Locations ..................................................................... 13
Figure 4 Output Modules .................................................................................................. 14
Figure 5 Timing System Diagram..................................................................................... 19
Figure 6 External Frequency Reference ........................................................................... 20
Figure 7 ATS-6501 Front Panel........................................................................................ 25
Figure 8 ATS-6501 Rear Panel......................................................................................... 28
Figure 9 Rear Panel Connections...................................................................................... 29
Figure 10 Flash Card......................................................................................................... 30

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1 General Information
1.1 Introduction
The ATS-6501 Tflex is a state-of-the-art GPS Disciplined time and frequency reference.
It utilizes an internal rubidium (Rb) atomic clock and low noise synthesizer (LNS) in conjunction
with GPS measurements to provide outputs that are characterized by the short-term stability of
the atomic clock and the long-term stability of the GPS constellation. Additionally, it provides
the user with the capability to enhance the frequency stability and holdover performance of the
unit by using an external cesium (Cs) clock as the reference. This provides a scalable architecture
that allows users to fulfill a wide range of current and future requirements with a single unit. The
ATS-6501 is suitable for a variety of precise time and frequency applications.
The 1 Pulse per Second (PPS) accuracy and frequency stability of the ATS-6501 is
further enhanced by using a dual-frequency (L1/L2) GPS receiver. The dual-frequency receiver
applies corrections to the GPS timing signals that remove a significant portion of the errors due to
ionospheric delay. The measurements can also be made available to users for the purpose of
modeling the total electron content (TEC) of the ionosphere.
In applications where reliability is a must the ATS-6501 is capable of operating from an
AC (100 – 240VAC, 50-60 Hz) or DC Power -48 VDC (SELV type) (-18 to -60 VDC) source and
comes with two fully redundant power supplies. The unit is capable of operating from a single
supply in the event one of the two power supplies fails.
The ATS-6511 is a fiber distribution system that derives its references and stability from
at least one ATS-6501. The ATS-6511 has two fiber I/O connections that allow for two-way time
transfer between the two systems. This capability allows the ATS-6511 outputs to be set on time
in relation to the ATS-6501 providing the reference signals and also provides for precise
calibration through the two-way time transfer. A 4372A module can be ordered and installed in
an ATS-6501 to supply the fiber signals to a ATS-6511. The fiber connection includes all timing
signals to provide the same capability and performance of the ATS-6501 in the ATS-6511. A
TSC-4340 distribution amplifier can be connected to a 4372A output to provide up to 8 more
outputs to ATS-6511s. The 4372A module includes input capability to monitor the status of each
ATS-6511 connected either directly to the 4372A module or through a TSC-4340 distribution
amplifier.
1.2 Ordering Information
ATS 6501A (Tflex): Standard dual frequency GPS time and frequency standard. Dual AC
input supplies included. Requires external frequency reference or internal Rubidium
reference and includes two 1 PPS/DC IRIG, one 10 MHz, and one AM IRIG output module.
A dual frequency GPS antenna is included with unit.
Option D (DC Power Input): Provides DC input (-48 VDC (SELV type) (-18 to -60 VDC))
capability instead of AC for one of the supplies. The second power supply is still AC.
Option D2 (Dual DC Power Input): Provides dual DC input (-48 VDC (SELV type) (-18 to
-60 VDC)) capability instead of AC.

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Option F (Front Panel Memory Card): Provides access to the unit’s non-volatile memory
via the front panel. This option allows users to perform a complete software upgrade in the
field without returning the unit to Symmetricom. Additionally, the unit can be declassified
by simply removing the flash card from the system.
Option R (Internal Rb Reference): Integrates an internal Rubidium (Rb) frequency reference
as part of the unit. This allows the unit to operate without using an external frequency
reference as well as steer the internal reference based upon the clock offset and GPS
measurements.
Output Cards: The ATS-6501 has five output cards available:
1. 4395A-10 Four 10Mhz Outputs
2. 4395A-5 Four 5Mhz Outputs
3. 4394A Programmable PPS and DC IRIG Module. Users can define the
signal types and operating parameters. Default set up is two
1PPS Outputs and two DC IRIG Outputs(Default = B000)
4. 4387A Four Modulated IRIG Outputs (Default = B120) or NASA36
5. 4372A Four output single mode fiber optic module for supplying signals
to a TSC-4340 or ATS-6511
OP001 USB Console Cable: Allows users to connect to the system Command Port via a
serial cable.
OP002 USB External Reference Communication Cable: Provides a serial communications
port to an external frequency reference (i.e. 5071A).
TSC-4340AS-8S: 1 U fiber expansion chassis with single mode input and 8 single mode
outputs
Notes:
1. The correct Symmetricom part number is constructed by appending the desired options to the base
model in alphabetical order. None of the options are mutually exclusive so users can select as many options
as desired.
Example Part Number: ATS-6501-DFR
Description: Tflex with 1 AC input and 1 DC input option, front panel memory option, and internal rubidium
clock reference option.
2. Antenna cables sold separately.
3. All units include an antenna, network time protocol (NTP), RS232 control of an external 10 MHz source
via USB, Ethernet control, and data logging capabilities.
4. Contact Symmetricom (www.symmetricom.com) for current pricing and availability.
5. OP001 and OP002 are DTE; this may require the use of a null modem serial cable.

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2 Installation
The ATS-6501 provides a number of features which may require additional setup and this
section provides a guideline for the basic setup. After completing this section, the ATS-6501 will
produce timing outputs to the coarse calibration accuracies specified in Appendix A. The ATS-
6501 is designed to be quickly and easily integrated with other system components. Just a few
steps are required in setting up the system so that it will begin producing accurate timing outputs.
In order to set the system up, users will need to power up the system and set up communications
in order to have access to the system command port.
2.1 Powering on the ATS-6501
Apply power to the system by supplying input power to at least one of the two power
supplies. When power is applied to the ATS-6501 the front panel will go through a self test and
then the ATS-6501 will begin booting up.
Note: If power is applied to both power supplies the Status Indicator on the front panel of both
power supplies should be green. If power is applied to only one of the two supplies the power
supply without input power should have a red Status Indicator the units Alarm Indicator should be
red.
Note: The ATS-6501 front panel Power-On Self Test (POST) will occur even if the front panel
software flash is removed.
A. The Date/Time display will sequentially test each segment on each individual position
within the display.
B. One at a time, each position of the display will display the number 8 starting from the far
left and working to the right.
C. Each LED below the Date/Time Display (Alarm, Oscillator Locked, GPS Tracking, NTP
Locked, & Outputs Enabled) will be turned on one at a time starting from the left to right.
As each LED is tested it will be green, then red, and then turn off with the exception of
the GPS Tracking indicator, this indicator will turn red, then green, then off.
D. The Date/Time display will then display “-9876543210” on the front panel.
E. Lastly the Date/Time display will have a “-“ in the center of each position in the display.
F. When the unit starts the application, the Oscillator Lock, GPS Tracking, and NTP Locked
indicators will turn red momentarily the go out.
G. While the ATS-6501 is booting up and waiting for the internal oscillator to lock the LED
indicators on the front panel below the Date/Time display should be off and the bars in
the display after the POST will move to the top, then center, then bottom and then go out.
This display will repeat as long as the unit is not tracking GPS.
Caution: The default antenna supply voltage is ZERO. If the antenna requires power from the
ATS-6501 to operate the system will stay in this mode until the antenna is properly configured.
This prevents the system from potentially damaging any antennas until the antenna supply voltage
is set properly.
As the ATS-6501 warms up, the Oscillator Lock indicator should come on within 5
minutes after the system is turned on. The Alarm light may turn on momentarily after the

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Oscillator Lock light comes on. This is normal and does not indicate there is a problem with the
unit.
2.2 Communicating with the ATS-6501
Operators are capable of communicating with the system through a LAN connection or
via one of the USB Ports when using OP001 USB to Serial cable to access the command port.
2.2.1 DHCP
The ATS-6501 runs DHCP by default and will therefore automatically be assigned an IP
address if it is connected to a network with a DHCP server. The ATS-6501 will display the
current IP address assigned to the unit in the Date/Time display after pressing and releasing the
Display pushbutton on the front panel. Users can use this IP Address to access the systems
command port.
Note: If the LAN Cable is not connected to the unit an IP Address is not assigned and the front
panel display button will not display an IP address for the system. Once the LAN cable is
connected to the unit it will automatically attempt to obtain an IP address from a DHCP Server.
If this does not work you may need to power cycle the unit.
2.2.2 Static IP Addresses
If you require a Static IP Address there are two options to set the network information in
the system.
2.2.2.1 Network
If the network has a DCHP Server you can obtain the IP Address (ip addr) by pressing
and releasing the Display pushbutton on the front panel. Telnet into the system using “telnet ip
addr 1700”. Once the “ATS-6501>” prompt is displayed run the network_config command to
manually configure the IP address for the unit. See Section (2.2.3).
If the network does not have a DHCP Server, press and hold the front panel display
pushbutton for ~10 seconds until the display shows the IP Address of 192.168.0.1. This
temporarily sets the IP Address of the unit. Telnet into the system using “telnet 192.168.0.1
1700”. Once the “ATS-6501>” prompt is displayed use the network_config command to
manually configure the IP address for the unit. (See section 2.2.3).
2.2.2.2 Console Cable
This feature allows local users to set the unit up without having to access the system via
the network. Connect a terminal to one of the USB ports on the rear panel using the USB to
Serial conversion cable (OP001). Changes can be made using any terminal program (e.g.,
HyperTerm, TeraTerm) from the serial port of a computer/terminal. The communication settings
are 115200 Baud, No Parity, 8 Data Bits, and 1 Stop Bit. Once connectivity is established the
user will see the ATS-6501> command prompt. Execute the network_config command to set the
IP Address, Netmask, Broadcast IP, and/or Default Gateway for the system if you are using a
static IP Address. See Section (2.2.3).
Note: Make sure the USB-to-Serial Converter (OP001) is installed in one of the two USB ports
when the system is powered on. If not, power the system down, plug the cable in and re-apply