TrueTime XL-DC User manual

[phone] | [email protected] | artisantg.com
-~
ARTISAN
®
~I
TECHNOLOGY
GROUP
Your definitive source
for
quality
pre-owned
equipment.
Artisan Technology
Group
Full-service,
independent
repair
center
with
experienced
engineers
and
technicians
on staff.
We
buy
your
excess,
underutilized,
and
idle
equipment
along
with
credit
for
buybacks
and
trade-ins
.
Custom
engineering
so
your
equipment
works
exactly as
you
specify.
•
Critical
and
expedited
services
•
Leasing
/
Rentals/
Demos
• In
stock/
Ready-to-ship
•
!TAR-certified
secure
asset
solutions
Expert
team
ITrust
guarantee
I
100%
satisfaction
All
tr
ademarks,
br
a
nd
names, a
nd
br
a
nd
s a
pp
earing here
in
are
th
e property of
th
e
ir
r
es
pecti
ve
ow
ner
s.
Find the Microsemi / Symmetricom / TrueTime 142-400-50 at our website: Click HERE

Model XL-DC
Serial Number__________________
September 15, 1997
Revision E

TrueTime, Inc. •2835 Duke Court •Santa Rosa, CA 95407 PHONE [phone] •FAX [phone]
www.truetime.com E-MAIL [e-mail]
FCC Notice and Compliance Statement
Model:
XL-DC, 151-600 RD-05, 820-500
XL-DC, 151-601 NTS-90, NTS-305
XL-DC, 151-601-178-1 NTS-90, NTS-405
XL-DC, 151-602 NTS-90, 600-210
XL-DC, 151-650 NTS-90, 600-310
XL-DC, 151-652 NTS-90, 600-410
XL-DC, 151-652-382 NTS-90, NIC-205
GPS-PC, 560-5500 NTS-90, NIC-305
PC-SG2, 560-5503 NTS-90, NIC-405
GPS-VME, 560-5600 NTS-100, 600-201
VME-SG2, 560-5608 NTS-100, 600-301
PCI-SG, 560-5900 NTS-100, 600-401
GPS-PCI, 560-5900-3 NTS-100i, NIC-215
GPS-PCI, 560-5901 NTS-100i, NIC-315
GPS-PCI, 560-5901-1 NTS-100i, NIC-415
GPS-605, 820-501-000 NTS-200-101 (48 VDC)
NMC-100, 820-501-001 TIMEVAULT 6000-100
GPS-605, 820-501-003 56000 DRC, 560-197-10
FCC Notice
This device has been tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a commercial installation. This device generates,
uses, and can radiate radio frequency energy and, if not installed and used in accordance with
the instruction manual, may cause harmful interference to radio communications. Operation of
this equipment in a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his own expense.
Caution: Any changes or modifications not expressly approved by the grantee of this device
could void the user’s authority to operate the equipment.
FCC Compliance Statement
This device complies with Part 15 of the FCC rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept
any interference received, including interference that may cause undesired operation
I:\Notices\FCC-A.DOC Rev. H

142-603.ADD 1 of 1 Rev. A
Addendum for 142-603
Antenna Downconverter Assembly
PHYSICAL SPECIFICATIONS
Antenna Downconverter Size: 4.4 in. dia. x 2.1 in.
(11.17 cm. dia. x 6.85 cm.)
Note: Antenna DownConverter Units are mounted on a 12-inch long PVC nipple with a 3/4-inch
Male Pipe Thread (MPT) on both ends. The above specified overall lengths of the Antenna
DownConverter Units are therefore increased by approximately 11.25 inches, when the
mounting nipple is included.
Antenna DownConverter Weight: 0.60 lb (.272 Kg)
(Including Mtg. Nipple)
Antenna DownConverter Available lengths = 150 - 1500 ft. (standard length 50 ft.)
Cable, RG-58: 2.7 lb (1.23 Kg) per 100 ft.
ANTENNA CABLE DELAY ENTRY/REQUEST
The as shipped default antenna cable delay is +60 nS. When the downconverted antenna is
being used, 150 nS should be added to the cable delay entered.

142-612.ADD 1 of 1 Rev. A
Addendum for 142-612
Antenna Assembly
PHYSICAL SPECIFICATIONS
Antenna Size: 2.625 in. dia. x 1.5 in.
(6.67 cm. dia. x 3.81 cm.)
Note: The Antenna is mounted on a 12-inch long PVC nipple with a 3/4-inch Male Pipe Thread
(MPT) on both ends. The above specified overall length of the Antenna. Units are therefore
increased by approximately 11.25 inches when the mounting nipple is included.
Antenna Weight: 0.55 lb (.250 Kg)
(Including mtg. nipple)
Antenna Cable, RG-59 Standard length = 50 ft.
1.2 lb (.545 Kg)
Optional Antenna Cable, RG-59 Available lengths to 200 ft.
2.7 lb (1.23 Kg) per 100 ft.
OPERATING SPECIFICATIONS
Antenna Power Regulated +5 Volts DC @ <25mA
Antenna Frequency (L1) 1575.42 MHz
Code Coarse Acquisition (C/A) Code
ENVIRONMENTAL SPECIFICATIONS
Operating Temperature: -40°to +70°C (-40°to +158°F)
Storage Temperature: -55°to +85°C (-67°to +185°F)
Humidity: 100%, condensing

DISPOSAL.ADD 1 of 1 Rev. N/C
ADDENDUM
RACK MOUNTING
Rack mounting instructions are found in Section II of the manual. Do not block ventilation openings.
Doing so may cause the unit to exceed the maximum operating temperature of +50°C.
LITHIUM BATTERY
Part number 350-019 is a lithium battery. “CAUTION: DANGER OF EXPLOSION IF BATTERY IS
INCORRECTLY REPLACED. REPLACE ONLY WITH THE SAME OR EQUIVALENT TYPE
BATTERY, AS RECOMMENDED BY THE MANUFACTURER.”
If the battery is replaced, it must be disposed of or recycled in accordance with all local, state, and
federal laws. Batteries may be returned to TrueTime, Inc. for disposal.

SCHEMTC.ADD 1 of 1 Rev. N/C
NOTICE ON
SCHEMATICS
Please be advised that there may or may not be
references in the text of this manual to schematic
drawings. TrueTime’s general policy is to not include
schematics because they may contain proprietary
information. If you require copies of any schematic,
please contact:
Customer Service
[email protected]
Phone: [phone]
Fax: [phone]

X
XL LD DC CM MA AN N. .d do oc cO Op pt ti io on ns sR RE EV V E E
MODEL 151-XXX-XXX
Installed Options Checklist
GPS-XL MODULE OPTION(S)
( ) Down Converter
( ) TTL Time Code Output ( ) IRIG B ( ) IRIG E ( ) IRIG H
( ) TTL Frequency Output(s) ( ) 10 MPPS ( ) 5 MPPS ( ) 1 MPPS
( ) SINE Frequency Output(s) ( ) 10 MHz ( ) 5 MHz ( ) 1 MHz
( ) Alarm Output (open collector)
( ) 1 KPPS Output
( ) 60 PPS Output
( ) Programmable Pulse Output (PPO)
( ) Slow Code Output
( ) Time Interval/Event Timing Input (TI-ET)
( ) Frequency Measurement Input (FREQ MEAS)
( ) External Oscillator Control (includes Parameter Entry/Request)
( ) RS-422 or RS-485 Serial Interface (replaces RS-232 Interface)
ADDITIONAL OPTION(S) Assembly
( ) Power Supply Option Manual Section IX
( ) Parallel BCD Time Output Manual Section XI
( ) IEEE-488 Interface Manual Section XII
( ) FTM (Frequency and Time Deviation Monitor) Manual Section XIII
( ) Disciplined Rubidium Oscillator Manual Section XIV
( ) Disciplined High Stability Quartz Oscillator Manual Section XV
( ) Low Phase Noise Output(s) Manual Section XVI
( ) Disciplined Quartz Oscillator Manual Section XVII
( ) Disciplined HP5071 Cesium Oscillator Manual Section XVIII
( ) Display Backlight Manual Section XIX
( ) Frequency Synthesizer (2.048 / 1.544 MHz) Manual Section XX
( ) Differential GPS Input Manual Section XXI
( ) Auxiliary Reference Input Manual Section XXII
( ) Telecommunications Framed Output (T1 or E1) Manual Section XXIII
( ) Video Time Inserter / IRIG B Sync Generator Manual Section XXIV
( ) Fiber Optic Link Manual Section XXV
( ) Code Output Board / IRIG B Sync Generator Manual Section XXVI
( ) NTS-XL Network Time Server Manual Section XXVII
( ) PTTI Interface Option Manual Section XXVIII
( ) N8 Frequency Synthesizer Manual Section XXIX
( ) Network Interface Card Manual Section XXX
( ) 1, 5, 10 Sine Manual Section XXXI
( ) Have Quick II Manual Section XXXII
SPECIAL OPTION(S) DOCUMENTATION
( ) Special Option Manual Section X

X
XL LD DC CM MA AN N. .d do oc ci iR RE EV V E E
TABLE OF CONTENTS
SECTION TITLE
I GENERAL INFORMATION
1-1 INTRODUCTION
1-2 LIMITED WARRANTY
1-3 LIMITATION OF LIABILITY
1-4 PROPRIETARY NOTICE
1-10 PHYSICAL SPECIFICATIONS
1-11 ENVIRONMENTAL SPECIFICATIONS
1-12 POWER INPUT SPECIFICATIONS
1-13 BATTERY SPECIFICATIONS
1-14 TIMING/FREQUENCY PERFORMANCE SPECIFICATIONS
1-15 INTERFACE SPECIFICATIONS
1-20 INPUTS AND OUTPUTS
1-21 1 PPS OUTPUT (STANDARD)
1-22 IRIG B OUTPUT (STANDARD)
1-30 TTL TIME CODE(S) IRIG B, IRIG E, OR IRIG H (OPTION)
1-31 1, 5, OR 10 MPPS OUTPUT(S) (OPTION)
1-32 1, 5, OR 10 MHz OUTPUT(S) (OPTION)
1-33 1 kPPS OUTPUT (OPTION)
1-34 SLOW CODE OUTPUT (OPTION)
1-35 PRECISION 60PPS OUTPUT (OPTION)
1-36 ALARM OUTPUT-OPEN COLLECTOR (OPTION)
1-37 PROGRAMMABLE PULSE OUTPUT (OPTION)
1-38 EXTERNAL OSCILLATOR CONTROL DAC OUTPUT (OPTION)
1-50 EXTERNAL OSCILLATOR INPUT (OPTION)
1-51 TIME INTERVAL/EVENT TIMING INPUT (OPTION)
1-52 FREQUENCY MEASUREMENT INPUT (OPTION)
1-60 SERIAL INTERFACE
1-61 RS-232/RS-422 CONNECTION
1-62 SERIAL DATA FORMAT
1-63 EXCLUSIVE USE
II INSTALLATION
2-1 OVERVIEW
2-2 PROCEDURE
2-3 SPECIAL CONSIDERATIONS FOR EXTERNAL OSCILLATOR CONTROL OPTION
2-4 RACK MOUNTING
III OPERATION
3-1 INTRODUCTION
3-2 GENERAL OPERATION
3-3 XL-DC START-UP
3-4 SATELLITE ACQUISITION
3-10 OPERATIONAL MODES
3-11 AUTO MODE
3-12 SURVEY MODE
3-13 TIME MODE

X
XL LD DC CM MA AN N. .d do oc ci ii iR RE EV V E E
TABLE OF CONTENTS (Continued)
SECTION TITLE
III (Cont.) OPERATION
3-20 TIME QUALITY INDICATION
3-21 FRONT PANEL INTERFACE
3-22 NUMERIC DISPLAY
3-23 ALPHANUMERIC DISPLAY
3-24 TIME PUSH-BUTTON
3-25 STATUS PUSH-BUTTON
3-26 POSITION PUSH-BUTTON
3-27 KEYPAD OPERATION
3-28 SELECTING FUNCTIONS AND ENTERING DATA
3-99 KEYPAD FUNCTION LIST
3-100 KEYPAD FUNCTION 00 - KEYPAD HELP FUNCTION
3-101 KEYPAD FUNCTION 01 - TIME ZONE ENTRY/REQUEST
3-102 KEYPAD FUNCTION 02 - 12/24 HOUR FORMAT ENTRY REQUEST
3-103 KEYPAD FUNCTION 03 - TIME/DATE ENTRY
3-104 KEYPAD FUNCTION 04 - SERIAL PORT SETUP
3-105 KEYPAD FUNCTION 05 - TIME QUALITY ENABLE/SETUP
3-106 KEYPAD FUNCTION 06 - KEYPAD LOCKOUT ENABLE
3-107 KEYPAD FUNCTION 07 - EXTERNAL OSCILLATOR ENABLE (OPTION)
3-113 KEYPAD FUNCTION 13 - WORST-CASE TIME ERROR REQUEST
3-114 KEYPAD FUNCTION 14 - EXTERNAL OSCILLATOR PARAMETER ENTRY/REQUEST
(OPTION)
3-116 KEYPAD FUNCTION 16 - EMULATION MODE ENABLE
3-116.1 SERIAL PORT EMULATION COMMANDS
3-116.2 MODE C - CONTINUOUS TIME, ONCE PER SECOND
3-116.3 MODE F - FORMAT THE TIME MESSAGE
3-116.4 MODE R - RESET TO DEFAULT AND MODE C
3-116.5 MODE T - TIME ON REQUEST
3-117 KEYPAD FUNCTION 17 - SLOW CODE SETUP (OPTION)
3-118 KEYPAD FUNCTION 18 - SOFTWARE VERSION REQUEST
3-128 KEYPAD FUNCTION 28 - TIME INTERVAL/EVENT TIMING INPUT (OPTION)
3-129 KEYPAD FUNCTION 29 - FREQUENCY MEASUREMENT INPUT (OPTION)
3-131 KEYPAD FUNCTION 31 - BACKLIGHT ENABLE
3-150 KEYPAD FUNCTION 50 - POSITION ENTRY/REQUEST
3-151 KEYPAD FUNCTION 51 - ANTENNA CABLE DELAY ENTRY/REQUEST
3-152 KEYPAD FUNCTION 52 - DISTRIBUTION CABLE DELAY ENTRY/REQUEST
3-153 KEYPAD FUNCTION 53 - OPERATIONAL MODE ENTRY/REQUEST
3-155 KEYPAD FUNCTION 55 - ALTITUDE UNITS ENTRY/REQUEST
3-156 KEYPAD FUNCTION 56 - AVERAGE POSITION ENTRY/REQUEST
3-160 KEYPAD FUNCTION 60 - SATELLITES LIST REQUEST
3-165 KEYPAD FUNCTION 65 - SATELLITE SELECT
3-166 KEYPAD FUNCTION 66 - DAYLIGHT SAVING ENABLE
3-168 KEYPAD FUNCTION 68 - YEAR ENTRY (GPS EPOCH MANAGEMENT)
3-169 KEYPAD FUNCTION 69 - SELECT LOCAL/STANDARD/GPS/UTC TIME
3-171 KEYPAD FUNCTION 71 - OSCILLATOR STATISTICS REQUEST
3-172 KEYPAD FUNCTION 72 - FAULT STATUS REQUEST

X
XL LD DC CM MA AN N. .d do oc ci ii ii iR RE EV V E E
TABLE OF CONTENTS (Continued)
SECTION TITLE
III (Cont.) OPERATION
3-173 KEYPAD FUNCTION 73 - REQUEST/SET ALARM STATUS/CONTROL
3-179 KEYPAD FUNCTION 79 - WARM START
3-197 GENERAL SERIAL INPUT AND OUTPUT FORMAT
3-198 SERIAL ERROR MESSAGES
3-199 SERIAL FUNCTION LIST
3-201 SERIAL FUNCTION F01 - TIME ZONE ENTRY/REQUEST
3-202 SERIAL FUNCTION F02 - 12/24 HR FORMAT ENTRY/REQUEST
3-203 SERIAL FUNCTION F03 - TIME/DATE ENTRY/REQUEST
3-205 SERIAL FUNCTION F05 - TIME QUALITY ENABLE/SETUP
3-206 SERIAL FUNCTION F06 - KEYPAD LOCKOUT ENABLE
3-207 SERIAL FUNCTION F07 - EXTERNAL OSCILLATOR ENABLE (OPTION)
3-208 SERIAL FUNCTION F08 - CONTINUOUS TIME ONCE PER SECOND ENABLE
3-209 SERIAL FUNCTION F09 - TIME ON REQUEST ENABLE
3-211 SERIAL FUNCTION F11 - TIME OUTPUT FORMAT ENTRY/REQUEST
3-213 SERIAL FUNCTION F13 - WORST-CASE TIME ERROR REQUEST
3-214 SERIAL FUNCTION F14 - EXTERNAL OSCILLATOR PARAMETER ENTRY/REQUEST
(OPTION)
3-215 SERIAL FUNCTION F15 - EXCLUSIVE USE ENABLE
3-217 SERIAL FUNCTION F17 - SLOW CODE SETUP (OPTION)
3-218 SERIAL FUNCTION F18 - SOFTWARE VERSION REQUEST
3-226 SERIAL FUNCTION F26 - PROGRAMMABLE PULSE OUTPUT (OPTION)
3-228 SERIAL FUNCTION F28 - TIME INTERVAL/EVENT TIMING INPUT (OPTION)
3-229 SERIAL FUNCTION F29 - FREQUENCY MEASUREMENT INPUT (OPTION)
3-250 SERIAL FUNCTION F50 - POSITION ENTRY/REQUEST
3-251 SERIAL FUNCTION F51 - ANTENNA CABLE DELAY ENTRY/REQUEST
3-252 SERIAL FUNCTION F52 - DISTRIBUTION CABLE DELAY ENTRY/REQUEST
3-253 SERIAL FUNCTION F53 - OPERATIONAL MODE ENTRY/ REQUEST
3-255 SERIAL FUNCTION F55 - ALTITUDE UNITS ENTRY/ REQUEST
3-256 SERIAL FUNCTION F56 - AVERAGE POSITION ENTRY/ REQUEST
3-260 SERIAL FUNCTION F60 - SATELLITES LIST REQUEST
3-265 SERIAL FUNCTION F65 - SATELLITE SELECTION
3-266 SERIAL FUNCTION F66 - DAYLIGHT SAVING ENABLE
3-268 SERIAL FUNCTION F68 - YEAR ENTRY (GPS EPOCH MANAGEMENT)
3-269 SERIAL FUNCTION F69 - SELECT LOCAL/STANDARD/GPS/UTC TIME
3-271 SERIAL FUNCTION F71 - OSCILLATOR STATISTICS REQUEST
3-272 SERIAL FUNCTION F72 - FAULT STATUS REQUEST
3-273 SERIAL FUNCTION F73 - REQUEST/SET ALARM STATUS/CONTROL
3-279 SERIAL FUNCTION F79 - WARM START
IV NOT USED
V NOT USED

X
XL LD DC CM MA AN N. .d do oc ci iv vR RE EV V E E
TABLE OF CONTENTS (Continued)
SECTION TITLE
VI CONFIGURATION/ASSEMBLY DRAWINGS
VII NOT USED
VIII IRIG B, IRIG H AND IRIG E TIME CODE FORMATS
8-1 INTRODUCTION
8-2 IRIG CODE FORMAT
8-3 WORST-CASE TIME ERROR FLAGS
8-10 SPECIAL IRIG B TIME CODE FORMAT (EMBEDDED GPS DATA OPTION)
FIGURE 8-1 IRIG B TIME CODE
FIGURE 8-2 IRIG E TIME CODE
FIGURE 8-3 IRIG H TIME CODE
IX POWER SUPPLY OPTION
X SPECIAL OPTION DOCUMENTATION
XI PARALLEL BCD TIME OUTPUT OPTION
XII IEEE-488 INTERFACE OPTION
XIII FTM (FREQUENCY AND TIME DEVIATION MONITOR) OPTION
XIV DISCIPLINED RUBIDIUM OSCILLATOR OPTION
XV DISCIPLINED HIGH STABILITY QUARTZ OSCILLATOR OPTION
XVI LOW PHASE NOISE OUTPUT OPTION
XVII DISCIPLINED QUARTZ OSCILLATOR OPTION
XVIII DISCIPLINED HP5071 CESIUM OSCILLATOR OPTION
XIX DISPLAY BACKLIGHT OPTION
XX FREQUENCY SYNTHESIZER OPTION
XXI DIFFERENTIAL GPS INPUT OPTION
XXII AUXILIARY REFERENCE INPUT OPTION
XXIII TELECOMMUNICATIONS FRAMED OUTPUT (T1 or E1) OPTION
XXIV VIDEO TIME INSERTER / IRIG B SYNC GENERATOR OPTION
TABLE OF CONTENTS (Continued)
SECTION TITLE

X
XL LD DC CM MA AN N. .d do oc cv vR RE EV V E E
XXV FIBER OPTIC LINK OPTION
XXVI CODE OUTPUT OPTION
XXVII NTS-XL NETWORK TIME SERVER OPTION
XXVIII PTTI INTERFACE OPTION
XXXIX N8 FREQUENCY SYNTHESIZER
XXX NETWORK INTERFACE CARD
XXXI 1, 5, 10 SINE
XXXII HAVE QUICK II

X
XL LD DC CM MA AN N. .d do oc c1 1- -1 1R RE EV V E E
SECTION I
GENERAL INFORMATION
1-1 INTRODUCTION
This manual provides the user of the Model XL-DC-600, XL-DC-601 or XL-DC-602 Time and
Frequency Receiver all of the information necessary to properly install, operate and utilize all of its
features.
The information in this manual includes normal installation procedures, as well as any maintenance and
adjustment data that may be required to facilitate field repairs.
The purpose of the Model XL-DC is to provide accurate time, frequency and position as derived from
Coarse Acquisition (C/A) Link 1 (L1) signals transmitted by the NAVSTAR Global Positioning System
(GPS) satellites. In addition, it provides high resolution measurements of external time and frequency
signals applied as inputs to the XL-DC versus the GPS reference. The XL-DC is usable on a
world-wide basis under any weather conditions.
The XL-DC is completely automatic in satellite acquisition and time and frequency synchronization.
When the unit is first installed (or if the unit is moved more than 100 km, or if the internal battery was
discharged), acquisition time is shortened if the operator enters a position accurate to better than
100 km (approximately one degree in latitude and longitude).
The XL-DC receiver will operate when the satellites are 10 degrees above the horizon and their signals
are not obstructed. Whenever entered position information is less accurate than 10 m, the XL-DC will
first have to accurately ascertain its antenna position by tracking four or more satellites and performing
a long term (24 hours) average of position fixes in order to maintain time and frequency accuracy and
stability within specification. From that point on, the XL-DC will require only one satellite (above 10
degrees) to maintain valid time and frequency. However, operation to specified stability requires four or
more satellites. When no satellites are in view, the XL-DC will continue to output its signals using either
the internal (or OPTIONAL external) disciplined oscillator.
1-2 LIMITED WARRANTY
Each new product manufactured by TrueTime is warranted for defects in material or workmanship for a
period of one year from date of shipment ("Limited Warranty"). Defects in material or workmanship
found within that period will be replaced or repaired, at TrueTime's option, without charge for material or
labor, provided the customer returns the equipment, freight prepaid, to the TrueTime factory under this
limited warranty. TrueTime will return the repaired equipment, freight prepaid, to the customer's facility.
This one year Limited Warranty does not apply to any software or to any product not manufactured by
TrueTime.
If on-site warranty repair or replacement is required, the customer will be charged the then current field
service rate for portal-to-portal travel time plus actual portal-to-portal travel charges. There is no
charge for on-site warranty repair labor.

X
XL LD DC CM MA AN N. .d do oc c1 1- -2 2R RE EV V E E
Products not manufactured by TrueTime but included as integral part of a system (e.g. peripherals,
options) are warranted for 90 days, or longer as provided by the original equipment manufacturer, from
date of shipment.
Aside from the Limited Warranty set forth above, TrueTime makes no other warranties, express or
implied, of merchantability, fitness for purpose or of any other kind or description whatsoever.
By purchasing any product manufactured by TrueTime, the buyer consents to and agrees with
TrueTime that as a result of the exclusion of all warranties, expressed or implied, of merchantability,
fitness for purpose, or otherwise, except for the limited one-year warranty for defects in material and
workmanship for products manufactured by TrueTime, that the Buyer has the sole responsibility to
assess and bear all losses relating to (1) the ability of the product or products purchased to pass
without objection under the contract description among merchants and buyers in the trade; (2) the
conformity of the product or products to fair average quality within its contract description; (3) the fitness
of the product for the ordinary purposes for which such product is used; (4) the consistency of quality
and quantity within each unit of product or products and among all units involved; (5) the adequacy of
containers, packaging and labeling of the product or products; (6) the conformity of the product,
promises or affirmations of fact (if any) made on its label or container; and (7) the conformity of the
product to standards of quality observed by other merchants in the trade with respect to products of
similar description.
1-3 LIMITATION OF LIABILITY
By purchasing any product from TrueTime the Buyer consents to and agrees that the Buyer's sole and
exclusive remedy for any damages or losses incurred by the Buyer as a result of TrueTime's breach of
its one-year Limited Warranty for defects in materials and workmanship or otherwise in connection with
any claim respecting the product shall be limited to the repair or replacement of the product or a refund
of the sales price of the product.
In no event shall the Buyer be entitled to recover consequential damages or any other damages of any
kind or description whatsoever.
1-4 PROPRIETARY NOTICE
THIS DOCUMENT, WHETHER PATENTABLE OR NON-PATENTABLE SUBJECT MATTER,
EMBODIES PROPRIETARY AND CONFIDENTIAL INFORMATION AND IS THE EXCLUSIVE
PROPERTY OF TRUETIME, INC. IT MAY NOT BE REPRODUCED, USED OR DISCLOSED TO
OTHERS FOR ANY PURPOSE EXCEPT THAT FOR WHICH IT IS LOANED, AND IT SHALL BE
RETURNED UPON DEMAND.
1-5 through 1-9 reserved

X
XL LD DC CM MA AN N. .d do oc c1 1- -3 3R RE EV V E E
1-10 PHYSICAL SPECIFICATIONS
The XL-DC is a 19” rack-mounted product with the following physical specifications:
XL-DC Receiver Size: 1.75 in x 17.0 in x 9.70 in
(4.45 cm x 43.18 cm x 24.64 cm)
Standard 19" EIA Rack System, hardware included, slides optional.
Antenna Size: 2.625 in dia. x 1.5 in
(6.67 cm dia x 3.81 cm)
Antenna Down Converter Size: 4.4 in dia. x 2.1 in
(Optional) (11.17 cm dia. x 6.85 cm)
Note: Antenna and Antenna Down Converter Units are mounted on a 12 inch long PVC nipple with
3/4 inch Male Pipe Thread (MPT) on both ends. The above specified overall lengths of the Antenna
and Antenna Down Converter Units are therefore increased by approximately 11.25" when the
mounting nipple is included.
XL-DC Receiver Weight: 7.0 lb max. (3.175 kg)
Antenna Weight: 0.70 lb (0.318 kg)
(Including mtg. nipple)
Antenna Down Converter Weight: 0.601 lb (0.272kg)
(Including mtg. nipple)
(Optional)
Antenna Cable, RG-59: Standard length = 50 ft
1.2 lb (0.545 kg)
Antenna Down Converter Available lengths = 150 - 1500 ft (standard length 50 ft)
Cable, RG-58: 2.7 lb (1.23 kg) per 100 ft
(Optional)
1-11 ENVIRONMENTAL SPECIFICATIONS
Operating Temperature:
Antenna or Ant/Down Converter: -40°to +70°C (-40°to +158°F)
XL-DC Receiver: 0°to +50°C (+32°to +122°F)
Storage Temperature:
Antenna or Ant/Down Converter: -55°to +85°C (-67°to +185°F)
XL-DC Reciever: -40°to +85°C (-40°to +185°F)
Humidity:
Antenna or Ant/Down Converter: 100%, condensing
XL-DC Receiver: 95%, non-condensing

X
XL LD DC CM MA AN N. .d do oc c1 1- -4 4R RE EV V E E
1-12 POWER INPUT SPECIFICATIONS
AC Power: 95-260 VAC, 47 to 440 Hz, < 15 W
DC Power: 120-370 VDC, < 15 W
1-13 BATTERY SPECIFICATIONS
The battery provides standby power to the XL-DC memory.
Battery type: Lithium, 3.5 Volt
Battery life: 15000 hours with power off.
Shelf life 10 years when powered (or GPS-XL JP1 removed)
Part number 350-019 is the lithium battery. "CAUTION: DANGER OF EXPLOSION IF BATTERY IS
INCORRECTLY REPLACED. REPLACE ONLY WITH THE SAME OR EQUIVALENT TYPE
BATTERY, AS RECOMMENDED BY THE MANUFACTURER."
If the battery is replaced, it must be disposed of or recycled in accordance with all local, state, and
federal laws. Batteries may be returned to TrueTime, Inc. for disposal.
1-14 TIMING/FREQUENCY PERFORMANCE SPECIFICATIONS
All performance specifications are valid when the antenna's geodetic position is known within 10 m in
WGS-84 and four or more satellites are being tracked under the current conditions of Selective
Availability (SA) as experienced at product release in March of 1994. When operating with the
standard TCXO as internal oscillator, all covers must be in place in order to meet the stated
stability specifications. During periods without SA, timing performance is improved to the ±100 ns
level.
The GPS-XL core receiver specifications are:
Frequency: 1575.42 MHz (L1 signal).
Code: Coarse Acquisition (C/A) code.
Tracking: Up to six satellites.
Acquisition Time: Less than 2 min if satellites visible, position correct within 1 km. Position errors
greater than 100 km may require 15 min or longer, with satellites visible. See
Section III.
Single Fix Within 25 m (SEP) referred to WGS84 when sequentially tracking four (4) or
Position Accuracy: more satellites with a PDOP < 6; 100 m (2 dRMS) if SA is enabled.
24 Hour Averaged
Position Accuracy: < 10 m

X
XL LD DC CM MA AN N. .d do oc c1 1- -5 5R RE EV V E E
The XL-DC timing and frequency specifications are:
1 PPS Output GPS Time ±150 ns
Accuracy: UTC-USNO <40 ns rms (150 ns peak)
Frequency Output
Accuracy: < 3 x 10-12
Frequency/Timing Allan Deviation,
Stability: 1 x 10-9 @ 1 sec
3 x 10-10 @ 10 sec
3 x 10-10 @ 100 sec
3 x 10-12 @ 1 day
Oscillator 2x10-6, over 0°C to 50°C when not
Stability: tracking satellites.
IRIG B Amplitude Modulated Output (STANDARD):
Accuracy: 10 µs to UTC
IRIG B DC Level Shift Output (OPTION):
Accuracy: 150 ns to UTC, 100 ns without SA
Time Interval/Event Timing Input (OPTION):
Resolution: 30 ns, single shot.
Accuracy: 150 ns + 30ns/2
Frequency Measurement Input (OPTION):
Resolution: 6 x 10-11 @ 1 second interval
Accuracy: 3 x 10-12
Stability: Same as Frequency & Timing Stability
1-15 INTERFACE SPECIFICATIONS
The standard serial data port is a bidirectional EIA standard RS-232C interface. RS-422 is available as
an option. The specifications are:
Data: Time, day of year through milliseconds, in ASCII characters, output once per
second or on request. Also special functions as listed in Section III.
Data Rates: User-selectable on Models XL-DC-601/602 from 300, 600, 1200, 2400, 4800,
9600 and 19200 bps. Fixed on Model XL-DC-600 (user-specified).
Data Bits: User-selectable on Models XL-DC-601/602 from 7 or 8. Fixed on Model
XL-DC-600 (user-specified).
Parity: User-selectable on Models XL-DC-601/602 from even, odd or none.
Fixed on Model XL-DC-600 (user-specified).
Stop Bits: User-selectable on Models XL-DC-601/602 from 1 or 2. Fixed on Model
XL-DC-600 (user-specified).

X
XL LD DC CM MA AN N. .d do oc c1 1- -6 6R RE EV V E E
Connector: Male 9-pin D subminiature.
Pin Assignment: See Section 1-60.
1-16 through 1-19 reserved
1-20 INPUTS AND OUTPUTS
A combination of up to five option input and output signals may be connected to the XL-DC via rear
panel mounted BNC connectors.
STANDARD OUTPUTS:
1-21 1 PPS OUTPUT (STANDARD)
A time-stable ACMOS levels 50 Ω1 PPS output is connected to a rear panel BNC connector. The
rising edge of this pulse coincides with the start of the second. The pulse width is 20 µs. If no satellites
are being tracked, the 1 PPS pulse will be as stable as the internal (or external if so configured)
oscillator of the XL-DC. The 1 PPS output is capable of driving a 50 Ωload. This output is valid
whenever the XL-DC has an accurate position and is tracking at least one satellite.
Pulse width: 20 µs
On time edge: Rising
Amplitude: TTL Levels into 50 Ω
Drive: ACMOS
1-22 IRIG B OUTPUT (STANDARD)
An IRIG B Amplitude Modulated 1 kHz carrier output is connected to a rear panel BNC connector. The
primary purpose of the IRIG B time code output is to drive slave displays manufactured by TrueTime.
Refer to Section VIII for a full description of this code. When using this code for other than driving the
TrueTime Models RD-B, RMD-B, SF-DC or 560 Distribution Amplifier, it should be noted that four bits in
the "control functions" portion of the IRIG B code encode the TIME QUALITY INDICATORS. These are
fully described in Manual Section VIII.
The modulated 1 kHz sine wave is capable of driving a 600 Ωload. The high level of the code is
2.5 ±0.25 Vp-p and the low level is 0.75 ±0.1 Vp-p into 600 Ω. The open circuit levels are twice those
into 600 Ω, i.e. the source impedance is 600 Ω.
Time Code: Amplitude-Modulated IRIG B
Carrier: 1KHz
Amplitude: 5.0 Vp-p high, 1.5 Vp-p low, no load
Output Z: 600 Ω
1-23 through 1-29 reserved