Operation . Orolia NetClock/GPS 9283


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Operation
. Orolia  NetClock/GPS 9283  | Manualzz

Spectracom Corporation Model 9283

4 Operation

Operation of the 9200 series NetClock is relatively intuitive and requires little operator intervention during normal network operations.

4.1 Front Panel

The front panel of the NetClock consists of one Ethernet connector which has two small indicator lamps, two main status LED’s and two LCD displays. The two status lights are “Sync” and “Power”. The LCD’s are configurable to display various time, data, version information formats. Refer to Figure 4-1 for a picture of the front panel.

The Spectracom NetClock has two main status LEDs present on the front panel. These status lights provide the user with the indication that power is applied to the unit (Power LED) and that the NetClock is currently synchronized or not synchronized (Sync LED). The power light will be blank if power is not applied or green if power is applied. The Sync light has many states to indicate the current status of the unit.

The Ethernet connector provides an interface to the network for NTP synchronization and to obtain access to the Web Browser. The Ethernet connector has two small indicator lights just above the connector. These lights are known as Good Link (Green LED) and Activity (Orange

LED). The Good Link light indicates a connection to the network is present. The activity light will blink when network traffic is detected.

The states of the Power, Sync and Ethernet LED’s are listed in Section 4.1.1.

Figure 4-1: Front Panel Display

At power up, a quick LED test is run. The unit displays a RedGreen – Orange sequence to ensure the operation of the LEDs.

The table on the following page describes the operation of the LEDs. In this table, the terms

Blink” and “Flash” are used.

Blink is defined as ½ second on, ½ second off

Flash is defined as

1 /

20

second on,

19 /

20 second off

NetClock/GPS Instruction Manual 4-1

Model 9283 Spectracom Corporation

POWER Green On

Off

SYNC Multi Off

Power is supplied to the NetClock.

Power is disconnected.

No fault but not synchronized to GPS.

Holdover spec has not been met.

Green On Synchronized to GPS. Time is valid and within the Locked to GPS accuracy specs.

Blinking

Green

Holdover mode. Not synchronized to GPS but time is still within Holdover accuracy specs. Also indicates the unit is synchronized with the optional dial-out modem (Option 03).

Yellow On No longer synchronized to GPS but no unit fault. Time accuracy may not be meeting holdover specs.

Blinking

Yellow

Unit is in power-up initialization mode. The unit is in this mode for the brief period between power on and when it is operationally ready to receive satellite data.

Flashing

Red

Ethernet

(left)

Yellow On

Off

GPS antenna fault. This flash may occur over any of the other color conditions at runtime.

Red On Unit fault. Time may not be valid. Overrides all other indicators.

Blinking

Red

If the unit fails Power On Self Test (POST) then the indicator will blink in a sequence indicating the failure code (consult factory)

LAN Activity detected.

No LAN traffic detected.

Ethernet

(right)

Green On

Off

LAN Link established 10 or 100 Mb/s.

No link established.

Table 4-1: Status Indicators

4.2 Rear Panel

The rear panel provides several different outputs that are available for interfacing the NetClock to various systems as well as a means of initially configuring the unit’s network settings. The rear panel also has a power jack for the power input, a connection for the GPS antenna and relay contacts for alarm monitoring and event alerts. Refer to Figure 4-2: for a drawing of the rear panel.

4-2 NetClock/GPS Instruction Manual

Spectracom Corporation Model 9283

The GPS Antenna connection is an “N” type connector for the GPS input from the antenna.

The power jack is the input for the DC power.

There are three configurable alarm/event relays ( Relays 1, 2, 3) available for remote alerts and

monitoring.

The Serial Setup Interface provides network and output port configuration capability.

The two RS-485 connectors ( RS-485 ports 1 and 2) provide an RS-485 data output for synchronizing devices that accept an RS-485 input, such as wall display clocks and add-on

Model 9188 Ethernet Time Servers.

Serial Comm 1 and Serial Comm 2 are “DB9 female” connectors that provide RS-232 data output to devices that can accept an RS-232 input for synchronization.

IRIG is a BNC output that provides an IRIG signal for synchronizing certain model voice recorders.

1PPS is a BNC output providing a once-per-second squarewave output.

FREQ OUT is a BNC output providing a 10MHz sinewave output.

FREQ OUT 1PPS OUT IRIG OUT

FREQ OUT 1PPS OUT

SERIAL COMM 1

RS-232

IRIG OUT

SERIAL COMM 2

RS-232

RELAY 1 RELAY 2 RELAY 3

C NC NO C NC NO C NC NO G

TIMER/ALARM RELAYS

SERIAL COMM 1

RS-232

POWER

+12VDC

SERIAL COMM 2

RS-232

RS-485 REMOTE

+ - G

RS-485 REMOTE

+ - G + - G

PORT 1 PORT 2

+ - G

PORT 1 PORT 2

GPS ANTENNA

SERIAL SETUP

INTERFACE

INTERFACE

RELAY 1 RELAY 2

RELAY 3

C NC NO C NC NO C NC NO G

TIMER/ALARM RELAYS

POWER

+12VDC

GPS ANTENNA

CHASSIS

GROUND

CHASSIS

GROUND

Figure 4-2: NetClock Rear Panel Detail

NetClock/GPS Instruction Manual 4-3

Model 9283 Spectracom Corporation

4.2.1 Event and Alarm Relay Outputs

The NetClock features three programmable relay outputs. The relays can be configured as major alarms, minor alarms, or events. They can control bells, whistles, sirens or other devices based on the event/alarm setup. Each event has an assigned start and stop time. An event can be scheduled for daily, monthly, or specific date occurrences.

An example of a daily event schedule is to sound the siren at the fire station at noon every day for five seconds. An example of a dated event is to schedule a test of the emergency evacuation horns on May 9th, 2007 from 10:00 AM to 10:05 AM.

The event timer is configured using the Web UI. Relays are configurable as events or alarm outputs. Refer to the appropriate configuration screens in Section 3 of this manual.

Event and alarm relay contacts are rated at 2.0 Amps, 30 VDC. The relays will be in the deenergized state (refer to Figure 4-3) when power is removed, when a major alarm is present and the relay is configured as a major alarm, or when an event is “on” and the relay is configured as an event output. The relay contacts can be referenced to ground by connecting to Pin G of the

Alarm Outputs connector.

G

GROUND

NC

NO

C

NC

NO

C

NC

NO

C

RELAY THREE

RELAY TWO

RELAY ONE

NOTE: Relays are shown in the de-energized state (event “off”).

Figure 4-3: Event and Alarm Relay Contacts

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Spectracom Corporation Model 9283

4.3 Leap Second occurrence

4.3.1 Reasons for a Leap Second Correction

A Leap Second is an intercalary, one-second adjustment that keeps broadcast standards for time of day close to mean solar time. Leap seconds are necessary to keep time standards synchronized with civil calendars, the basis of which is astronomical. They are used to keep the earth’s rotation in sync with the UTC time.

If it has been determined by the International Earth Rotation and Reference Systems Service

(IERS) that a Leap Second needs to applied, this time correction occurs only at the end of a

UTC month, and has only ever been inserted at the end of June 30 or December 31. A Leap

Second may be either added or removed, but in the past, the leap seconds have always been added because the earth’s rotation is slowing down.

Historically, Leap seconds have been inserted about every 18 months. However, the Earth's rotation rate is unpredictable in the long term, so it is not possible to predict the need for them more than six months in advance.

The NetClock can be alerted of impending leap seconds by either of the following methods:

1. GPS Receiver – The GPS satellite system transmits information regarding a Leap second adjustment at a specific Time and Date an arbitrary number of months in advance.

2. Modem – (Applicable to only units with Option 03 Modem installed). During a modem dial-out call, the call service indicates that a Leap second adjustment at the end of this current calendar month will occur.

4.3.2 Leap Second Alert Notification

The NetClock will announce a pending Leap Second adjustment by the following methods:

1. Data Formats 2 and 7 on the Serial and Remote Ports contain a Leap Second indicator.

During the entire calendar month preceding a Leap Second adjustment, these Formats indicate that at the end of the current month a Leap Second Adjustment will be made by having a ‘L’ rather than a ‘ ‘ (space) character in the data stream. Note that his does not indicate the direction of the adjustment as adding or removing seconds. These formats always assume that the Leap Second will be added, not removed.

2. NTP Packets contain two Leap Indicator Bits. In the 24 hours preceding a Leap Second

Adjustment, the Leap Indicator Bits (2 bits) which normally are 00b for sync are 01b (1) for Add a Leap Second and 10b (2) for remove a Leap Second. The bit pattern 11b (3) indicates out of sync and in this condition NTP does NOT indicate Leap seconds. The

Sync state indicates leap seconds by indicating sync can be 00b, 01b, or 02b.

NOTE: It is the responsibility of the client software utilizing either the Data Formats or NTP time stamps to correct for a Leap Second occurrence. The NetClock will make the correction at the right time. However, because computers and other systems may not utilize the time every second, the Leap second correction may be delayed until the next scheduled interval, unless the software properly handles the advance notice of a pending Leap Second and applies the correction at the right time.

NetClock/GPS Instruction Manual 4-5

Model 9283 Spectracom Corporation

3. The Dynamic System Information box in the “System Status” page located under the web page of “Status and Logs” will display a Leap Second Status box indicating +1 or -1

Leap second adjustment at the end of the month to users during the entire calendar month preceding the actual adjustment.

4.3.3 Sequence of a Leap Second Correction Being Applied

1. The following is the time output sequence that the Model 9283 will utilize to apply the

Leap second at UTC midnight (Not local time midnight. The Local time at which the adjustment is made will depend on which Time Zone you are located in).

A) Sequence of seconds output when adding a leap second:

56, 57, 58, 59, 60, 0, 1, 2, 3, …

B) Sequence of seconds output when removing Leap seconds:

56, 57, 58, 0, 1, 2, 3, 4, …

2. An entry will be made in the Operational log that the time was adjusted for a Leap

Second.

A) An example log entry for a Positive Leap Second is as follows:

TIME= 23:59:59 DATE= 2005-12-31

System Clock Service

Leap second inserted at end of month.

B) An example log entry for a Negative Leap Second is as follows:

TIME= 23:59:59 DATE= 2005-12-31

System Clock Service

Leap second removed at end of month.

4-6 NetClock/GPS Instruction Manual

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