IOC Operation


The TimeProvider operates with one or two Input/Output and Clock Modules (IOC) for redundant or non-redundant operation. The IOC accepts the incoming reference signal and decodes the SSM if present. With the system properly provisioned and a reference signal selected, the local oscillator in the IOC operates in one of the following modes:

After the IOC has been in the Normal lock mode for at least three days, SmartClock holdover mode becomes available. Compared to the normal holdover mode, SmartClock holdover mode provides a superior output quality.

IOC State

Explanation

INSRV

In Service. IOC is working correctly and may be used for output signal generation

OOSRV

Out of Service. IOC has been taken out of service, it will not be used to generate outputs or monitor inputs. No alarms are generated by the IOC.

IOC Status

Explanation

OK

OK. IOC is working correctly and can be used for output signal generation.

ALM

Alarm. An IOCFAIL alarm was reported. The IOC may not be producing outputs or monitoring inputs.

IOC Mode

Explanation

ACTIVE

Active. IOCs work as a pair with one active and the other in standby in a one plus one protection mode. The active IOC produces the signal output and monitors the inputs. The active IOC goes to standby if ordered by command, on circuit pack removal, or on IOC failure.

STANDBY

Standby. IOC is not in standby mode.

Clock Mode

Explanation

Warm-up

For up to 20 minutes after applying power to the shelf, the IOC operates in warm-up mode.

Fast-lock

After warm-up is complete, the IOC enters the fast-lock state and frequency-locks the local oscillator to the reference input.

Normal lock

After the IOC has completed the fast-lock cycle, it enters the normal lock mode and the TimeProvider uses the proper amount of filtering for the selected mode. When set to the SSU mode and locked to an active input traceable to a Primary Reference Source (PRS), the TimeProvider complies with the G.811 and GR-2830-CORE standards.

Holdover

If the reference signal is lost, the clock enters holdover mode. The accuracy of the TimeProvider output is then dependent on the quality level of the oscillator in the IOC.

Free-run

If the IOC starts without a system reference, the TimeProvider enters the free-run state after warm-up. If a reference is applied, the TimeProvider enters the fast-lock and then the normal-lock states.

Clock Type

Explanation

Type 1

The Type 1 oscillator meets or exceeds the ITU-T G.812 TYPEI specification.

ST3E

The ST3E oscillator meets or exceeds the ST3E requirements in ANSI T1.101 and Telcordia GR-244, as well as the ITU-T G.812 TYPE III specification.

Comms Status

Explanation

IMC1COMM-OK

IOC1 to IMC communication established.

IMC1COMM-FAIL

IOC1 to IMC communication failed.

IMC2COMM-OK

IOC2 to IMC communication established.

IMC2COMM-FAIL1

IOC2 to IMC communication failed.

Highest Alarm

Explanation

OK

No alarms reported.

CRITICAL

Critical alarm is the most sever alarm reported.

MAJOR

Major alarm is the most sever alarm reported.

MINOR

Minor alarm is the most sever alarm reported.

LED Name

Condition

Description

Power

Green

Off

Flashing Green

Power is On

Power is Off

Warming Up

Fail

Red

Off

Card failure

No failure

Alarm

Green

Off

Card alarm

No alarm

GPS

Q LED Off, A LED Off

Q LED Green, A LED Green

Q LED Green, A LED Off

Q LED Red, A LED Off

Disabled

Enabled, qualified, and active

Enabled, qualified, and not active

Enabled and not qualified

Holdover

Off

Red

Tracking at least one input

Tracking no inputs

Active

Green

Off

Card is active

Card is in standby mode

PRS

Q LED Off, A LED Off

Q LED Green, A LED Green

Q LED Green, A LED Off

Q LED Red, A LED Off

Disabled

Enabled, qualified, and active

Enabled, qualified, and not active

Enabled and not qualified

Input 1

Q LED Off, A LED Off

Q LED Green, A LED Green

Q LED Green, A LED Off

Q LED Red, A LED Off

Disabled

Enabled, qualified, and active

Enabled, qualified, and not active

Enabled and not qualified

Input 2

Q LED Off, A LED Off

Q LED Green, A LED Green

Q LED Green, A LED Off

Q LED Red, A LED Off

Disabled

Enabled, qualified, and active

Enabled, qualified, and not active

Enabled and not qualified