NETSYNC SUMMARY (NET SU)

Qualifiers:

<number>

<number> LAST <number of hours>

Purpose:

Provides a report on the behavior of the synchronization source.

Details:

The NETSYNC SUMMARY command shows the clock sources of the system.

The <number> qualifier identifies the shelf (1 or 2) on which the system clock being observed resides.

The <number of hours> qualifier specifies the number of past hours the report covers. The value entered can be digits in the range 0 through 24. When 0 is specified, the report covers the events within the portion of the hour prior to the command being entered (i.e., if the command is entered at 16:33 then the report covers the period 16:00 to 16:33).

If the NETSYNC SUMMARY command is issued and the node is not programmed in the Network Synchronization form to define the clock source, the system response is:

NETSYNC SUMMARY: Invalid command for MASTER SWITCH.

Netsync Summary Command Printout Headings (see Examples)

Heading

Description

TIME, START & END

Defines the interval of time for which the fields that follow apply. Normally, the smallest interval is one hour. An exception to this is when the system is up and then, shortly thereafter, switches activity.

ACT CLK

Indicates activity or non-activity of the system clock specified in the input parameters of the NETSYNC SUMMARY command. Non-activity is indicated by a blank entry.

SINGLE HITS

Indicates the number of times the specified system clock observed an unusual phase shift of the sync signal. Readings are taken every 100 ms. A single hit is considered to be a shift in phase which is corrected within 300 ms.

PHASE SHIFTS

Indicates the number of phase shifts which are not corrected within 300 ms but considered to be stable within 800 ms.

CONTROL RANGE

Provides a percentage estimate of the ability of the system clock to synchronize to the current source. A range of 100% indicates that the system clock and synchronizing source are both "healthy" and that there is maximum flexibility of the system clock to synchronize to the current source. Conversely, a low reading indicates that either the synchronizing source is drifting badly or the system clock has become degraded to a point where it should be replaced because it is no longer able to track the sync source over a wide range of clock frequency.

SYNCHRONIZING SOURCES USED

Indicates the synchronizing source(s) used by the system clock during the specified time. Note that the first source of the most recent entry (i.e., FREERUN in the example) identifies the current synchronization source. This field may also contain any of the following entries:

MASTER: Present when the Network Synchronization form which specifies the number of synchronization sources is empty (i.e., the system  assumes that the active system clock is the master synchronization source). Note that when in this
 mode the active system clock cannot monitor SINGLE HITS or PHASE SHIFTS. The Single Hits and Phase Shift fields contain zeros when the  system clock is in the MASTER mode. CONTROL RANGE will be driven slowly back to 100%.

LOCKACT: Abbreviation for Locked To Active
LOCKACT indicates correct system operation.

FREERUN: Indicates that system clock used none of the synchronization sources specified in the Network Synchronization form. This may be due to unstable or unavailable sources.

Decimal digits 1 through 8 indicate which of the synchronization sources, specified in the Network Synchronization form, were used by the active system clock.

Examples:

Entry: NET SU 1

System Response:

Time

Start

End

act

Single hits

Phase Shifts

Control Range

Sync Sources Used

12:03

12:13

ACT

0

0

99 - 99

1 2

Entry: NET SU 1 LAST 2

System Response:

Time

Start

End

act

Single hits

Phase Shifts

Control Range

Sync Sources Used

13:09

13:53

ACT

0

0

97-97

1

12:09

13:09

ACT

0

0

95-97

Freerun 1

11:09

12:09

ACT

0

0

94-99

Freerun 1