Symmetricom 5401, 5402 manual Enter Resync Delay, Enter Rate Threshold

Page 21

Operating Manual

Operation

Enter Resync Delay

When the 1 PPS In is lost or becomes invalid (rate threshold is exceeded), the unit is placed into a holdover mode. It remains in this mode until the 1 PPS In is valid for a time period (in seconds) determined by "Resync Delay". At five seconds before discipline restarts, a determination is made as to whether the 1 PPS Out will be resynchronized (jammed). This is based on the "Resync Delay". Refer to the Discipline Sequence flowchart in Figure 5.

Command Format:

Description:

dddd- Resync Delay; dddd (5 to 9999 seconds) is the number that determines how long the 1 PPS needs to be valid before disciplining starts.

Response Format:

Enter Rate Threshold

Command Format:

Description:

rrrrrr.rrr- Rate Threshold; rrrrrr.rrr (0 to 999999.999 microseconds) is the limit value that determines if the 1 PPS input is valid. When the 1 PPS is invalid, the DAC value will not change. The unit enters holdover. Holdover is exited when the "Resync Delay" requirements have been met.

Response Format:

PN 8500-0150, Rev. A, May 2005

13

Image 21 Contents
Airborne Disciplined Rubidium Oscillator Symmetricom, Inc Operating Manual Preface Limited WarrantyWhere to Find Answers to Product and Document Questions Limitation of LiabilityProprietary Notice Conventions Used in This Guide Operating Manual Preface Typographical Conventions When text appears It means This wayPN 8500-0150, Rev. A, May Contents-1 Operating Manual ContentsOperating Manual SpecificationsOperating Manual Introduction Product OverviewSymmetricom 5402 Disciplined Rubidium Oscillator Symmetricom 5401 Airborne Disciplined Rubidium OscillatorSymmetricom 5401 Installation Procedure InstallationOperating Manual Installation Unpacking and Inspection5401 Adjustment Locations Symmetricom 5401 AdjustmentsSymmetricom 5402 Rack Mounting Procedure Symmetricom 5402 Installation Procedure Symmetricom 5402 AdjustmentsSymmetricom 5402 Initial Operation Operating Manual Operation RS-232 Input/OutputStatus Request Operating Manual Operation DRO Commands Via RS-232 Description Discipline OffDynamic Gain Control Discipline OnEnter KM Enter KO1, KO2Minutes Enter Resync Threshold Enter DisgainEnter Rate Threshold Enter Resync DelayBurst Status Off Burst Status OnStatus will be output every second Turns burst status offRequest TI DRO Discipline Sequence FlowchartEnter DAC Value Request Firmware VersionDTyyy Firmware Number PN 8500-0150, Rev. A, May Enter Start-up Parameters Request Start-up ParametersOperating Manual Operation Revision Letter of Firmware Response Format Description Calibrate UnitReturns the unit to a default state Default Values Set DefaultsEnter 1 PPS Offset not implemented Request Setup ParametersInput Threshold High/Low Enter Oscillator Control Range not implemented Enter Programmable Delay ValueDesign Verify On/Off Enter Estimation Filter Time Constant Cal StatusEnter Dynamic Gain Factors Input Specifications and Characteristics Operating Manual SpecificationsInput Specifications and Characteristics Output Specifications and Characteristics Output Specifications and CharacteristicsCoherence a 5401 Indicators Front Panel Indicators Front Panel5402 Indicators Front Panel DRO Internal Time BasesOperating Manual Specifications DRO Internal Time Bases MHz Oven Oscillator10 MHz Oven Oscillator Weight DimensionsApproximately 8 pounds Approximately 10 pounds PN 8500-0150, Rev. A, MayEMI Environment