Z3801A
GPS Receiver
097-Z3801-01
Issue 1: May 00
User’s Guide
Copyright © 2000 Symmetricom, Inc. All rights reserved. Printed in U.S.A.
This guide describes how to install and operate the
Z3801A GPS Receiver. The information in this guide
applies to instruments having the number prefix
listed below, unless accompanied by a
“Manual Updating Changes” package indicating
otherwise.
SERIAL PREFIX NUMBER: 3506A and above
For assistance, contact:
Symmetricom, Inc.
2300 Orchard Parkway
San Jose, CA 95131-1017
U.S.A. Call Center:
888-367-7966 (from inside U.S.A. only – toll
free)
408-428-7907
Warning Symbols That May Be Used In This Book
Instruction manual symbol; the product will be marked with this
symbol when it is necessary for the user to refer to the
instruction manual.
Indicates hazardous voltages.
Indicates earth (ground) terminal.
U.K. Call Center:
+44.7000.111666 (Technical Assistance)
+44.7000.111888 (Sales)
Fax: 408-428-7998
E-mail: ctac@symmetricom.com
Internet: http://www.symmetricom.com
or
Indicates terminal is connected to chassis when such connection
is not apparent.
Indicates Alternating current.
Indicates Direct current.
Contents
In This Guide
Guide Organization..................................................................... vii
Description of the Z3801A GPS Receiver .............................. viii
Options ............................................................................................. ix
Accessories Supplied and Available.......................................... ix
Accessories Supplied ................................................................... ix
Accessories Available .................................................................. ix
Manuals............................................................................................xi
Supplied Manual ......................................................................... xi
Available Documents .................................................................. xi
1Getting Started
Z3801A Front Panel at a Glance ............................................... 1-2
Z3801A Rear Panel at a Glance ............................................... 1-3
Preparing the GPS Receiver for Use ...................................... 1-4
To Assemble and Install the Antenna System ........................ 1-4
To Assemble the DC Power Connector..................................... 1-5
Powering Up the Receiver......................................................... 1-6
Overview of the Power-Up Procedure (What to Expect) ......... 1-6
To Power Up the Receiver......................................................... 1-6
To Understand the Receiver Status Screen Data.................. 1-10
Installing the Automated SatStat Program for Continual
Status Updates ........................................................................... 1-11
Operating the Automated SatStat Program........................ 1-12
Customizing the Receiver Operation ................................... 1-13
Using Commands to Control Key Functions (Examples). 1-14
To Perform Basic Installation and Simple Customizing....... 1-14
If required, restore all of the Receiver’s internal settings
to their factory shipment values by invoking a system
preset.................................................................................. 1-14
Initiate “surveying”, an automatic determination of the
Receiver’s antenna position. ............................................. 1-15
Set the Receiver to compensate for the length of the antenna
cable. .................................................................................. 1-15
Set the Receiver to exclude satellites which appear below a
specified elevation angle. .................................................. 1-16
Set the Receiver to display local time rather than
UTC time. .......................................................................... 1-16
To Install With a Limited View of the Sky, To Bypass Position
Survey Operation .................................................................... 1-16
User Guide iii
Contents
2 Features and Functions
Chapter Contents ........................................................................ 2-2
Inputs ............................................................................................. 2-3
ANTENNA Input ...................................................................... 2-3
Recommended Antenna Cable Assemblies ........................2-3
Antenna Cable Length Delay ............................................. 2-5
DC INPUT J4 Power Jack ........................................................ 2-6
Outputs .......................................................................................... 2-7
10 MHz OUT J2 Output ........................................................... 2-7
10 MHz Outputs—via I/O Port 1 J3......................................... 2-7
1 PPS (One Pulse Per Second) Outputs—via I/O Port 1 J3 .... 2-7
RS-422 Serial Port, I/O Port 1 J3 ............................................. 2-8
Indicators ...................................................................................... 2-9
Power Indicator ......................................................................... 2-9
Enabled/Active Indicator .......................................................... 2-9
Alarm Indicator ......................................................................... 2-9
GPS Lock Indicator ................................................................... 2-9
Holdover Indicator .................................................................... 2-9
Connecting to a Computer ...................................................... 2-10
Operating Concepts .................................................................. 2-11
General .................................................................................... 2-11
Holdover Description .............................................................. 2-11
In Case of a Problem ................................................................. 2-12
Hours after powerup, Receiver not establishing GPS lock ... 2-12
Receiver not maintaining GPS lock ....................................... 2-13
3 Using the Receiver Status Screen
Chapter Contents ........................................................................ 3-2
Using and Reading the Receiver Status Screen ................... 3-3
Tutorial on Using the Status Screen to Interface With the
Receiver...................................................................................... 3-4
Demonstration of Holdover Operation ..................................... 3-8
Receiver Status Screen Data .................................................. 3-11
SYNCHRONIZATION Section of the Status Screen............. 3-12
SYNCHRONIZATION Summary Line ............................ 3-12
SmartClock Mode .............................................................. 3-12
Reference Outputs ............................................................. 3-13
ACQUISITION Section of the Status Screen ........................ 3-14
ACQUISITION Line.......................................................... 3-14
Tracking, Not Tracking..................................................... 3-15
Time ................................................................................... 3-16
iv User Guide
Contents
Position .............................................................................. 3-17
HEALTH MONITOR Section of the Screen...........................3-18
The Receiver Status Screen at a Glance .............................. 3-19
4 Command Listing and Status Information
Chapter Contents ........................................................................ 4-2
Z3801A Commands ...................................................................... 4-3
SCPI Conformance Information ............................................... 4-3
SCPI Syntax Conventions......................................................... 4-3
Description of Commands ......................................................... 4-3
Detailed Description of the Two Time Code Formats ........... 4-12
Status Information .................................................................... 4-14
Standard Event Register Bit Assignments............................ 4-14
Questionable Status Register Bit Assignments .................... 4-15
Operation Status Register Bit Assignments.......................... 4-15
Powerup Status Register Bit Assignments ............................ 4-16
Holdover Status Register Bit Assignments ........................... 4-16
Hardware Status Register Bit Assignments ......................... 4-17
Information that Appears in the Diagnostic Log............... 4-18
Model for Powerup, Locked, and Holdover States ............ 4-19
Error Messages........................................................................... 4-21
5 Specifications Summary
Specifications and Characteristics ......................................... 5-2
GPS Receiver Features ............................................................. 5-2
10 MHz Output Characteristics ............................................... 5-2
J2................................................................................................ 5-2
1 PPS Output Characteristics .................................................. 5-3
Front Panel Indicators (LEDs) ................................................. 5-3
Remote Interface (Port 1).......................................................... 5-3
Antenna and Cabling Information ........................................... 5-3
Environmental........................................................................... 5-4
58504A Antenna Assembly................................................. 5-4
GPS Time and Frequency Reference Receiver .................. 5-4
Power Requirements ................................................................. 5-4
General Information ................................................................. 5-4
Other Information ..................................................................... 5-4
Index
User Guide v
Contents
vi User Guide
In This Guide
This preface contains the following information:
• Guide Organization page vii
• Description of the Z3801A GPS Receiver page viii
• Options page ix
• Accessories Supplied and Available page ix
• Manuals page xi
Guide Organization
Table of Contents
In This Guide (this preface) introduces you to the User’s Guide, and
provides general information on the GPS Receiver.
Chapter 1, “Getting Started,” is a quick-start chapter that introduces
you to the GPS Receiver with a brief overview of the Receiver’s
indicators and connectors. Installation and power-up instructions, and
a section that provides sample commands to start operating the
Receiver are provided to get you familiar and comfortable with
operating the Receiver.
Chapter 2, “Features and Functions,” provides information on
Receiver’s features and functions, connecting to computers, and
problem solving (that is, a section titled “In Case of a Problem”).
Chapter 3, “Using the Receiver Status Screen,” provides
information on how to use the Receiver Status screen and the SatStat
program. An illustrated foldout of the Receiver Status screen, which is
a comprehensive summary of key operation conditions and settings, is
provided at the end of this chapter.
Chapter 4, “Command Listing and Status Information,” briefly
lists all of the commands that can be used to operate the Receiver and
provides Receiver status and error message information.
Chapter 5, “Specifications Summary,” lists the Z3801A
specifications and characteristics.
Index
User Guide vii
In This Guide
Description of the Z3801A GPS Receiver
The Z3801A GPS Receiver provides highly accurate time and
frequency outputs that can be used for synchronizing CDMA Cellular
Land Network wireless base stations.
The Receiver provides highly accurate timing. If a satellite signal is
lost, the Receiver automatically switches to holdover mode, which
ensures system synchronization for up to 24 hours with reduced
accuracy.
The Z3801A has the following rear-panel Input/Output connectors:
• an I/O Port 1 25-pin female rectangular D subminiature connector
(This connector provides two 1 PPS time outputs, two 10 MHz
frequency outputs, and an RS-422 serial interface port).
• 10 MHz output BNC connector
• an Antenna N-type connector
• Power input jack
The front panel contains six Light-Emitting-Diode (LED) indicators to
indicate that power has been applied (Power), the module has tracked
and locked on to one or more GPS satellites (GPS Lock), the GPS system
is operating in holdover mode (Holdover), and an error or invalid
condition exists due to system fault or reduced accuracy of the outputs
(Alarm), and two LEDs illuminated under user-defined conditions
(Enabled, Active).
The Z3801A has no front panel display or keypad entry. Information is
remotely entered into and retrieved from the Z3801A using customersupplied DCE (Digital Communications Equipment) connected to the
rear-panel 25-pin RS-422 serial interface port.
viii User Guide
In This Guide
Options
• Rack Mount Tray 29.5 inch (750-millimeter)
• CV90-14271-1 GPS Receiver Unit, +27 Vdc, beige, single output
• CV90-14271-2 GPS Receiver Unit, --54 Vdc, beige, single output
• CV90-14271-11 GPS Receiver Unit, -+27 Vdc, gray, single output
• CV90-14271-12 GPS Receiver Unit, --54 Vdc, gray, single output
• CV90-15357-1 GPS Receiver Unit, +27 Vdc, beige, single output
• CV90-15357-2 GPS Receiver Unit, --54 Vdc, beige, single output
• CV90-14805-1 Shelf, Dual GPS Receiver Mounting, beige
• CV90-14805-11 Shelf, Dual GPS Receiver Mounting, gray
Accessories Supplied and Available
Accessories Supplied
SatStat Program (59551-13401)
Accessories Available
For more details on available GPS accessories refer to the Designing
Your GPS Antenna System Configuration Guide (P/N 5964-9068E).
Refer to the subsections titled “Recommended Antenna Cable
Assemblies” and “Antenna Cable Length Delay” in Chapter 2 of this
guide for more cable information.
• CV90-14807 Coaxial cables
• CE90-14806 Antenna, GPS Receiver
• CE90-15275 Lightning Arrestor, GPS Receiver
• CE90-15276 Line Amplifier, GPS Receiver
• 58504A GPS Antenna Assembly
• 58510A GPS Antenna Environmental Cover and Ground Plane
(optional use with the 58504A GPS Antenna Assembly)
• 58513A GPS Antenna Assembly
1
• 58505B Lightning Arrester
• 58509A Antenna Line Amplifier (recommended for distances
greater than 175ft./53.3 meters for RG-213 cable; 200 ft/61 meters
for LMR cable)
User Guide ix
In This Guide
• 58518A RG-213 Antenna Cable Assembly (3.3 to 164.0 ft, or
1 to 50 meters)—TNC-to-N connectors
• 58519A RG-213 Interconnect Cable Assembly (3.3 to 164.0 ft, or
1 to 50 meters)—N-to-N connectors
• 58520A LMR 400
2
Antenna Cable Assembly (3.3 to 360.8 ft, or
1 to 110 meters)—TNC-to-N connectors
2
• 58521A LMR 400
Interconnect Cable Assembly (3.3 to 360.8 ft, or
1 to 110 meters)—N-to-N connectors
• 58518AA
3
RG-213 TNC-N Antenna Cable Assembly
(3.3 to 164.0 ft, or 1 to 50 meters) without connectors attached
3
• 58519AA
RG-213 N-N Interconnect Cable Assembly
(3.3 to 164.0 ft, or 1 to 50 meters)—without connectors attached
3
• 58520AA
LMR 4002 TNC-N Antenna Cable Assembly
(3.3 to 360.8 ft, or 1 to 110 meters)—without connectors attached
• 58521AA
3
LMR 4002 N-N Interconnect Cable Assembly
(3.3 to 360.8 ft, or 1 to 110 meters)—without connectors attached
1
The 58513A is a completely assembled unit, which includes the 58504A Antenna, a 4-foot cable, the
58510A environmental cover and ground plane, and a 1-foot stainless steel mounting mast.
2
LMR 400 cables are low-loss, less flexible than RG-213, but are very good coaxial cables.
3
These cables do not have the connectors attached. A connector kit is supplied.
xUser Guide
In This Guide
Manuals
Supplied Manual
Z3801A User’s Guide (this guide), P/N Z3801-01
User Guide xi
In This Guide
xii User Guide
1
Getting Started
Chapter 1 Getting Started
Z3801A Front Panel at a Glance
Z3801A Front Panel at a Glance
I N C O R P O R A T E D
Power
Enabled Active
123 45
1 When the Power indicator is illuminated, it
indicates that the proper input power is
supplied to the Receiver.
2 User-definable indicators labeled Enabled and
Active. These can be turned on through the
RS-422 port.
3 When the Alarm indicator is illuminated, it
indicates that the receiver has detected an
internal condition that requires attention.
GPS RECEIVER
Alarm
GPS Lock
4 When the GPS Lock indicator is illuminated, it
indicates that the Receiver is receiving the
GPS signal and is locked on one or more
satellite(s).
5 When the Holdover indicator is illuminated, it
indicates that the Receiver is NOT locked to
the GPS signal. The Receiver is keeping time
based on the internal reference oscillator
signal. The internal reference oscillator will
determine the accuracy of the 1 PPS signal
and the 10 MHz reference output. (See
specification for Accuracy in Holdover in
Chapter 5, “Specifications Summary,” in this
guide.)
Holdover
1-2 User Guide
Chapter 1 Getting Started
Z3801A Rear Panel at a Glance
Z3801A Rear Panel at a Glance
1
2
ANTENNA
J1 J2
!
I/O
Port 1
J3
4
10 MHz OUT
SERIAL PLATE
Made in U.S.A.
with domestic and
foreign content.
!
NRTL/C
TESTED TO UL 1950
WARNING:
To avoid electric shock:
Do not remove covers.
No user serviceable parts inside.
Refer all servicing to qualified personnel.
This unit must be earth grounded.
CAUTION
METRIC & INCH HARDWARE
CONSULT SERVICE MANUAL
DC INPUT
!
BTS
CV90 - 15357 - 1
19.5 - 30VDC
BSC
CV90 - 15357 - 2
38 - 60VDC
3
J4
E1
5
1 ANTENNA J1 N-type (female) connector.
2 10 MHz OUT J2 BNC (female) output connector
for user-specific applications.
3 DC INPUT J4 power connector.
User Guide 1-3
4 I/O Port 1 J3 25-pin female D Subminiature
RS-422 serial interface port for remote
control, monitoring, and retrieving of the
unit’s memory data. This port also provides
two 1 PPS time outputs, and two 10 MHz
frequency outputs.
5 E1 Ground stud provides a low impedance
ground for safety and systems grounding.
WARNING: Ground stud must be connected
to Safety Earth Ground.
Chapter 1 Getting Started
Preparing the GPS Receiver for Use
Preparing the GPS Receiver for Use
To Assemble and Install the Antenna System
CABLE CONSIDERATIONS. When using the antenna cables with the
GPS Receiver, you should observe certain precautions. Consult your
local electrical and building ordinance codes on how to install RG-213
cables (58518A/519A) or LMR 400 cables (58520A/521A). Certain
codes might require you to put the cables inside a conduit, or to use
cables made with a non-toxic fire retardant insulation.
To assist you with installing your GPS antenna system, refer to the
following documents:
• Information Notes that provide installation procedures for the
applicable GPS antenna and accessories that you purchase.
• The subsection titled “ANTENNA Input” in Chapter 2, “Features
and Functions,” of this guide.
To Assemble the DC Power Connector
1 Note that you will have to assemble your own dc power cable using
18 AWG connecting wires and a three-pin AMP Universal
MATE-N-LOKII® (female) connector plug (shown in Figure 1-1).
4
1
2
3
1 dc supply (+)
3 dc supply (-)
2 Not used
Figure 1-1. Three-Pin Plug Pinouts (Front View)
2 From the rear of the plug, connect the supply-side wire of the external
power supply or battery to pin 1 of the plug. Connect the external
1-4 User Guide
4 Cable wires
Chapter 1 Getting Started
Preparing the GPS Receiver for Use
battery’s return (ground) wire to pin 3. Use the rear-panel E1 ground
stud to connect the GPS Receiver chassis to a system ground.
3 Observing the correct polarity, attach the other ends of the wires to a
proper dc power source to operate the Receiver.
NOTE Do not apply power to the Receiver unless a fully operational antenna
system is connected to the rear-panel ANTENNA J1 connector.
Power applied with no antenna input can initiate an extended search
process that may increase time to reach GPS lock. You can halt the
extended search by disconnecting and reconnecting (cycling) the
external dc supply (you may need to leave power disconnected for
greater than five seconds).
User Guide 1-5
Chapter 1 Getting Started
Powering Up the Receiver
Powering Up the Receiver
Overview of the Power-Up Procedure (What to
Expect)
When you power up the GPS Receiver for the first time, you should
expect it to run through the following sequence:
• goes through internal diagnostics and all front-panel lights flash,
• acquires and tracks four satellites,
• computes the Receiver’s position,
• locks to the 1 PPS (one pulse-per-second) time standard provided by
GPS, and
• begins steady-state operation, acting as a source of timing and
synchronization information derived from the GPS standard.
Elapsed time for each step will vary, depending largely on how many
satellites your antenna is able to “see” when you power up. If many
satellites are visible when you power up, the Receiver will take at least
8 minutes and at most 25 minutes to calculate its position from the
constellation of satellites overhead. The derived position will be
improved over a period of time by further averaging. When the
GPS Lock indicator lights, the basic functionality of the Receiver is
available; however, optimal performance is delivered later.
To Power Up the Receiver
1 Connect the antenna system to the rear-panel ANTENNA J1 Type-N
connector of the Receiver as described in the instructions given in the
subsection titled “To Assemble and Install the Antenna System” on
page 1-4 of this chapter.
NOTE Although connecting the GPS Receiver to a terminal or computer isn’t
necessary for it to attain GPS lock, the terminal is needed for you to
observe the progress of the Receiver or to configure alarms.
2 Connect the GPS Receiver to your system DCE device (Digital
Communications Equipment) via the rear-panel I/O Port 1 J3
RS-422 port using an appropriate (customer supplied) system interface
cable as shown in Figure 1-2.
1-6 User Guide
Chapter 1 Getting Started
Powering Up the Receiver
NOTE Do not apply power to the Receiver unless a fully operational antenna
system is connected to the rear-panel ANTENNA J1 connector.
Power applied with no antenna input can initiate an extended search
process that may increase time to reach GPS lock. You can halt the
extended search by disconnecting and reconnecting (cycling) the
external dc supply (you may need to leave power disconnected for
greater than five seconds).
GPS Receiver
(Rear view)
DCE Device
Figure 1-2. Connecting the GPS Receiver to a DCE Device
(DTE-to-DCE Interface cable is customer supplied)
3 Turn your DCE device (or PC equipped with a correctly wired RS-422
serial-port connector) on.
You will need to run a terminal emulation program on your DCE device
in order to communicate via the RS-422 serial port. Most PCs contain a
terminal emulation program, especially PCs with Windows
application. If your PC does not contain a terminal emulation program,
purchase one of the following programs: PROCOMM PLUS
(DATASTORM Technologies, Inc.®), PROCOMM PLUS for Windows,
Cross Talk (Hayes®), or any other terminal emulation program.
(Note: Symmetricom is not endorsing any of these products.)
Another option to purchasing and installing a terminal emulation
program is to use the SatStat Program. See the section titled
“Installing the Automated SatStat Program for Continual Status
Updates” on page 1-11 for installation and operating information.
User Guide 1-7
Chapter 1 Getting Started
Powering Up the Receiver
4 Set the RS-422 port of your DCE device (or PC) to match the following
values:
Pace: NONE
Baud Rate: 19200
Parity: Odd
Data Bits: 7/char
Start Bits: 1
Stop Bits: 1
NOTE The RS-422 port configurations of the Receiver and the DCE device/PC
must be the same for communications between the two. Thus, for this
power-up procedure, set your DCE device/PC to match the default
values listed above.
5 Apply the proper power source to the rear-panel Power input jack of the
Receiver. (See the appropriate subsection titled “To Assemble the DC
Power Connector” on page 1-4)
The following sequence of events occurs after power is applied to the
Receiver.
a. Only the front-panel Power indicator lights.
b. After a moment, the Receiver runs through its self-test diagnostics
as indicated by the flashing front-panel indicators.
c. After the self test is completed, just the Power indicator remains lit.
If the Alarm indicator lights, a failure may have occurred during the
self test. Refer to Table 4-2 in Chapter 4, “Command Listing and
Status Information,” of this guide for information on the Alarm
capability.
d. The Receiver begins to search the sky for all available satellites.
1-8 User Guide
Chapter 1 Getting Started
Powering Up the Receiver
e. From the DCE device keyboard, type
:SYSTEM:STATUS? and press Enter (or Return).
Confirm that the scpi> prompt is displayed after pressing Return.
If no prompt or an error-number prompt (E-xxx>) is displayed, then
try typing the command again.
The computer displays the status screen as shown in the sample
status screen in Figure 1-3.
You must re-enter the :SYSTEM:STATUS? command each
time you want an updated status screen.
NOTE You have been provided a Windows program called SatStat, which
provides continual status updates of the GPS Receiver’s status screen.
If you are using an RS-422 equipped PC, it must have Windows
installed to operate the user interface application. The application is
easy to install and operate.
See the section titled “Installing the Automated SatStat Program for
Continual Status Updates” on page 1 in this guide.
f. When four or more satellites are tracked as will be indicated in the
status screen, automatic position computation is initiated.
g. Finally, the Receiver goes into steady-state operation (which
requires one satellite) and the GPS Lock indicator lights, indicating
the Receiver has locked on to the GPS signal.
After the initial powerup, the Receiver is set for basic operation.
That is, the Receiver operating parameters are set to their powerup
default values or states.
If you need to customize the Receiver operation, see the section titled
“Customizing the Receiver Operation” on page 1-13 for a list of key
things you may want to perform to customize the operating parameters
of the Receiver.
User Guide 1-9
Chapter 1 Getting Started
Powering Up the Receiver
---------------------------- ----------------------------
SYNCHRONIZATION
SmartClock Mode
Locked to GPS: stabilizing frequency...
>>
Recovery
Holdover
Power-up
ACQUISITION
Satellite Status
Tracking: 5
PRN El Az
ELEV MASK
HEALTH MONITOR
Self Test: OK | Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK
El
2
70
337
7
46
188
15
33
19
28
113
27
65
10
Az
82
91
.........................
.......................................
Not Tracking: 4
PRN
SS
134
117
54
29
128
12 11 292
16 24 243
*26 Acq..
31 -- ---
*attempting to track
......................................................
Receiver Status
[
Outputs Valid/Reduced Accura
Reference Outputs
TFOM
FFOM
1PPS TI
HOLD THR
Time
GPS
1PPS CLK Synchronized to GPS Ti
ANT DLY
Position
MODE
AVG LAT
AVG LON
AVG HGT
3
0
+20 ns relative to GPS
1.000 us
[GPS 1PPS CLK Accurate]
03:56:44 1994 DEC 01
120 ns
Survey: 57.3% complete
NW37:19:31.330
121:59:50.468
+54.89 m (MSL)
cy ]
[ OK ]
Figure 1-3. Sample Status Screen
To Understand the Receiver Status Screen Data
me
One of the key indicators on the screen is the ACQUISITION
status indicator. It shows “GPS 1 PPS Valid ” as soon as satellite
information is sufficient.
Refer to Chapter 3, “Using the Receiver Status Screen,” in this guide
for a tutorial on how to use the status screen (shown in Figure 1-3).
A reference section that defines the different data indicated in the
status screen is also provided in Chapter 3.
1-10 User Guide
Chapter 1 Getting Started
Installing the Automated SatStat Program for Continual Status
Updates
Installing the Automated SatStat Program for Continual Status Updates
This Windows application provides continual status updates of the
Receiver Status screen. Your PC must be equipped with a correctly
wired (See Table 2-3 in Chapter 2.) RS-422 serial-port adapter and
have Windows installed to operate the user interface application. The
application is easy to install and operate.
1 Insert the SatStat disk in drive A.
2 From the File menu in either the Program Manager or File Manager,
choose Run.
3 Type a:setup, and press Enter (or Return). The SatStat Setup screen
will appear, and installation will proceed.
4 Once the program is installed, you can start it by double-clicking the
SatStat icon that was created during the installation.
5 You should establish communication with the GPS Receiver.
This requires connection from the DCE device (Digital
Communications Equipment) via the rear-panel I/O Port 1 J3 RS-422
port using an appropriate (customer supplied) system interface cable.
Assuming you’ve got the cable attached to make this connection, you
may want to check the settings.
a. Select CommPort, then choose Settings.
The Communication Settings dialog box is displayed.
Unless someone has reprogrammed the CommPort settings on the
GPS Receiver, these settings are probably OK. The one setting that
is likely to need changing is the Com Port. The application defaults
it to Com1, but the serial port on your PC may be assigned to a
different Com Port. Select the appropriate setting. If you are unsure,
Com1 will be your best bet (worst case, you can cycle through all of
them until it works).
b. If you made any changes on this Settings form, select OK,
otherwise you can just Cancel.
User Guide 1-11
Chapter 1 Getting Started
Operating the Automated SatStat Program
Operating the Automated SatStat Program
1 Select CommPort, then choose Port Open.
The main form of the Receiver Status screen is displayed. The program
will send some commands to the GPS Receiver and then the main form
should begin to periodically update every few seconds. If you are
getting screen updates, proceed to the next step. Otherwise, something
is wrong with your CommPort settings or perhaps the physical
connection between your PC and the Receiver.
If you need to control the Receiver or query for the status of a setting of
the Receiver, use the “Control & Query” form (this form will usually be
stacked beneath the main form). To activate this form, click anywhere
on it. Select Control (or Query), then choose the type of control (or
query) you want. This will pull down a list of control (or query)
functions that you can choose from, and the corresponding command
will be displayed. To send the command, click on Send Cmd. Hence,
with the Control & Query form you can control the Receiver without
knowing the command or query.
More information about the Windows program is provided in the
“Getting Started” Help file.
2 Refer to the section titled “Using and Reading the Receiver Status
Screen” in Chapter 3, “Using the Receiver Status Screen,” of this guide
for a tutorial and demonstration of what to look for when viewing the
status screen.
1-12 User Guide
Chapter 1 Getting Started
Customizing the Receiver Operation
Customizing the Receiver Operation
Here are some key things you might want to perform to customize the
Receiver operation:
• Execute a system preset if you've found the Receiver in an
unknown or questionable operating state.
• Make the Receiver survey if it wasn’t already surveying.
• Set the antenna delay.
• Set the elevation mask angle.
• Set the time zone.
See the section titled “Using Commands to Control Key Functions
(Examples)” on the following page for more information.
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Chapter 1 Getting Started
Using Commands to Control Key Functions (Examples)
Using Commands to Control Key Functions
(Examples)
The operation of the GPS Receiver is designed to be as automatic as
possible. However, there are several situations where serial interface
control is required. The tasks described here are those most commonly
encountered.
For each task in this section, you can use either a terminal emulation
program or the SatStat program to issue the selected commands.
Additional information about the commands is provided in Chapter 4,
“Command Listing and Status Information,” of this guide.
To Perform Basic Installation and Simple
Customizing
After connecting the Receiver to the antenna, power source, DCE
device RS-422 port, and after the self test is completed, you may want
to complete installation using one or more of the capabilities described
below.
If required, restore all of the Receiver’s internal settings to
their factory shipment values by invoking a system preset.
After executing the system preset, the Receiver will begin normal
operation: it will acquire GPS signals, determine the date, time, and
position automatically, bring the reference oscillator ovens to a stable
operating temperature, lock the reference oscillator and its output to
10 MHz, and synchronize the 1 PPS output to UTC.
Settings affected by system preset are listed in Chapter 4, “Command
Listing and Status Information,” of this guide under the
:SYSTEM:PRESET command definition.
The Receiver is preset using the command:
:SYSTEM:PRESET
Note that system preset should be performed only when necessary.
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Using Commands to Control Key Functions (Examples)
Initiate “surveying”, an automatic determination of the
Receiver’s antenna position.
When “position survey” is invoked, the Receiver is set to ascertain the
position of its antenna automatically. This survey is important; correct
antenna position data is required for the Receiver to deliver specified
performance.
The Receiver uses data from orbiting satellites to survey; hence, the
antenna must be installed and operational for the survey to work.
However, if you have a limited view of the sky, you can complete basic
installation, then read forward to the section titled “To Install With a
Limited View of the Sky, To Bypass Position Survey Operation” on
page 1-16 for a means of overriding the survey operation and entering
position data directly.
The survey is an iterative process. The Receiver transits to “Position
Hold” when a usable position has been obtained.
Set the Receiver to survey using command:
:PTIME:GPSYSTEM:POSITION:SURVEY ONCE
Set the Receiver to compensate for the length of the
antenna cable.
The Receiver can be custom-configured to compensate for the length of
the antenna cable. The phase of the Receiver’s internal clock is
therefore offset from the GPS standard by the number of nanoseconds
of delay introduced through the antenna cable. The amount of error is
typically on the order of a few hundred nanoseconds. Should you decide
to correct for this error, Table 2-1A and Table 2-1B in Chapter 2,
“Features and Functions,” of this guide provides typical corrections for
standard antenna cable lengths.
Set the Receiver to compensate for antenna cable delay using
command:
:PTIME:GPSYSTEM:ADELAY <seconds>
or
:PTIME:GPSYSTEM:ADELAY <nanoseconds> NS
It is normal to observe that the Receiver momentarily goes into
holdover after any change in antenna delay.
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Using Commands to Control Key Functions (Examples)
Set the Receiver to exclude satellites which appear below a
specified elevation angle.
At the factory, and whenever the Receiver is preset, the Receiver is set
to seek satellites visible from zenith down to 10 degrees above the
horizon—down to an “elevation mask angle” of 10 degrees. The factory
elevation mask angle setting is intended to provide a full view of the
sky. The Receiver can be custom-configured to use a different elevation
mask angle.
Set the Receiver elevation mask angle using the command:
:PTIME:GPSYSTEM:EMANGLE <degrees>
Set the Receiver to display local time rather than
UTC time.
Set the offset from UTC time to local time using the command:
:PTIME:TZONE <hours>, <minutes>
To Install With a Limited View of the Sky, To Bypass
Position Survey Operation
In order to reach steady-state operation, the Receiver must know the
position of the antenna. The Receiver is able to collect enough
information from four satellites to compute this position. The “position
survey operation” takes in data from the satellites, iterating until the
antenna position is known to the required precision. The Receiver will
automatically use its position survey operation on powerup and
:SYSTEM:PRESET.
Alternatively, if the antenna position is already known to seconds of
arc, and the Receiver cannot see enough satellites, you may manually
enter antenna position as shown in the following text.
NOTE An incorrect value for the position will confuse the Receiver, and will
degrade the timing information accuracy or even prevent tracking any
satellites.
Set the Receiver antenna position using the command format shown
below (for clarity, an example is provided rather than a complex
description.):
:PTIM:GPS:POS N,37,19,32.5,W,121,59,51.2,40.12
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Set the latitude, longitude, and height parameters to represent the
latitude (in degrees, minutes, seconds), longitude (in degrees, minutes,
seconds), and altitude in meters above mean sea level (MSL). (Note: if
you know the position to this accuracy, the desired position is of the
antenna rather than the Receiver.)
NOTE For faster acquisition following repair, or power failure you may want
to write down the position after the Receiver has completed its survey.
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