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5401 Airborne Disciplined Rubidium Oscillator
5402 Disciplined Rubidium Oscillator
Operating Manual
Preliminary Rev. A, May 2005
PN 8500-0150
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Symmetricom, Inc. 2300 Orchard Parkway San Jose, CA 95131-1017 U.S.A. http://www.symmetricom.com Copyright © 1999–2005 Symmetricom, Inc. All rights reserved. Printed in U.S.A. This manual is provided to assist the user in the operation and maintenance of the supplied equipment or software. It is recognized that multiple copies may be required to support even a single unit, and for this reason, permission is hereby granted to reproduce the supplied manual for the purpose stated above, provided
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Operating Manual Preface Preface Limited Warranty Each new product manufactured by Symmetricom 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 Symmetricom’s option, without charge for material or labor, provided the customer returns the equipment, freight prepaid, to the Symmetricom factory under this limited warranty. Symmet
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Operating Manual Preface Limitation of Liability By purchasing any product from Symmetricom, 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 Symmetricom’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 prod
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Operating Manual Preface ESD Caution: To avoid personal injury and electrostatic discharge (ESD) damage to equipment, do not disregard ESD cautions. All ESD cautions use this symbol. ESD cau- tions are installation, operation, or maintenance procedures, practices, conditions, or statements that if not strictly observed, may result in possible personal injury, electro- static discharge damage to, or destruction of, static-sensitive components of the equip- ment. Electrical Shock Caution: To avo
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Operating Manual Preface Table 2 Typographical Conventions When text appears ... it means: this way... SSU-2000 User’s Guide The title of a document. SSU An operating mode, alarm state, status, or chassis label. CRITICAL IOC1 Select File, Open... Click the Open option on the File menu. A named keyboard key. Press Enter The key name is shown as it appears on the keyboard. An Press ; explanation of the key’s acronym or function immediately fol- lows the first reference to the key, if required.
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Operating Manual Contents Preface Limited Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Limitation of Liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv Proprietary Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv Where to Find Answers to Product and Document Questions . . . . . . . . . . . . . iv Warnings, Cautions, Recommendati
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Operating Manual Burst Status On. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Burst Status Off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Request TI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Enter DAC Value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Request Firmware Version . . . . . . . . . . . . . . .
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Operating Manual Introduction 1 — Introduction Product Overview The purpose of the Symmetricom 5401 Airborne Disciplined Rubidium and 5402 Disciplined Rubidium Oscillator (DRO) is to provide a precise time and frequency reference for other equipment. The DRO will base this reference on a precise 1 PPS input, typically from a GPS Receiver. At the 1 PPS time signal input rollover, the DRO will measure the time difference between it and the internal Rubidium oscillator. It will continuously co
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Operating Manual Introduction Symmetricom 5401 Airborne Disciplined Rubidium Oscillator The Symmetricom 5401 is built in an airborne package that is powered by standard aircraft power (+28 VDC) and is installed by mounting the chassis on a flat base plate. Refer to Chapter 4 for complete specifications. Figure 1 Symmetricom 5401 3-View Symmetricom 5402 Disciplined Rubidium Oscillator The Symmetricom 5402 is built in a standard rack mount configuration that is powered by commercial power any
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Operating Manual Installation 2 — Installation Installation This section describes the unpacking, inspection, installation, and operation of the Symmetricom 5401 and 5402 Disciplined Rubidium Oscillators. Unpacking and Inspection The DRO is packaged in one shipping container. Inspect the unit for visible damage (scratches, dents, etc.). If the instrument is damaged, immediately notify both Symmetricom and the responsible carrier. Keep the shipping container and packing material for the car
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Operating Manual Installation The 5401 is now operational and will begin to discipline the Rubidium using the control parameters that were previously stored in battery-backed RAM when the unit was last powered-down. Symmetricom 5401 Adjustments The amplitude of each of the 10 MHz outputs can be individually adjusted with potentiometers located on the 3-Channel Distribution Amplifier (Assembly 35039). In order to gain access to these adjustments, do the following: (The 5401 is viewed from t
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Operating Manual Installation Symmetricom 5402 Rack Mounting Procedure The 5402 is designed for standard nineteen-inch rack mounting. Optional chassis slides are recommended if the unit is to be installed in an equipment rack. If slides are not used, a supporting bar or tray should be provided for the rear of the instrument. The chassis slides attach to the sides of the 5402. To mount the slides, use six # 8/32 screws, 1/2 inch long (three on each side). Caution: If the 5402 is mounted in
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Operating Manual Installation Symmetricom 5402 Installation Procedure 1. Install the unit in the desired location and connect the unit to an AC power source. Refer to Chapter 4 for specifications and connector designations and locations. 2. Connect the 1 PPS input to its 1 PPS source and connect the 1 PPS and 10 MHz outputs to their desired destinations. Connection to the RS232 I/O is not necessary for operation, but it is desirable in order to monitor status or enter new control parameter
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Operating Manual Operation 3 — Operation Neither the 5401 nor the 5402 have any external manual controls. Signal output amplitude is controlled by internal potentiometers, which are located as described in Chapter 2. All operational control of the DRO is accomplished by means of an RS-232 input/output port. RS-232 Input/Output The DRO has been equipped with an RS-232 interface using a 13-pin MS type connector designated as J14 RS232 on the 5401, and using a DB15 connector designated as J3
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Operating Manual Operation Table 1 DRO Commands Via RS-232 Status Request Command Format: PN 8500-0150, Rev. A, May 2005 8
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Operating Manual Operation Description: Rx - Rubidium lock; x=0 not Locked, x=1 Locked Dx - Discipline On/Off; x=0 discipline off, x=1 discipline on Px - 1 PPS input present; x=0 not present, x=1 present Vx - Valid 1 PPs; x=0 unstable, x=1 stable. Time change in the 1 PPS is less than the rate threshold. Ttttttt.ttt - Time Interval; tttttt.ttt is the time interval (0 to 999999.999 microseconds) of the last 1 PPS event. Sssssss.s - Seconds Counter; ssssss.s is the second count (0 to 99999
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Operating Manual Operation Response Format: Discipline On Command Format: Description: The oscillator discipline is turned on. When the conditions are favorable, the discipline algorithm will control the oscillator. Response Format: Dynamic Gain Control Command Format: Description: The dynamic gain value determines the response time of the control loop. This command sets the upper and lower limit. Fgg.g - Dynamic Gain Floor; the lowest value allowed for dynamic gain. Cgg.g - Dynamic Gain C
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Operating Manual Operation Dynamic Gain Time Constant 4 90 minutes 5 70 minutes 8 45 minutes 10 35 minutes 20 17 minutes 30 11 minutes Response Format: Enter KM Command Format: Description: kkkkkk - Base number for Km; kkkkkk (000000 to 999999) represents a number from 0 to 0.999999. Km controls the mix ratio of offset error and frequency error compensation in the discipline algorithm. Response Format: Enter KO1, KO2 Command Format: PN 8500-0150, Rev. A, May 2005 11
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Operating Manual Operation Description: nnnnnn - Base number for Ko1; nnnnnn (000000 to 999999) represents a number from 0 to 0.999999. Ko1 controls the cut off frequency of the offset error noise filter. oooooo - Base number for Ko2; oooooo (000000 to 999999) represents a number from 0 to 0.999999. Ko2 controls the cut off frequency of the frequency error noise filter. Response Format: Enter Disgain Command Format: Description: ddddd - Base number for Disgain; ddddd (00000 to 99999) contro
