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VOA

Variable Optical Attenuator (VOA) is required in a DWDM network to adjust the power levels in order to control the transmission performance. VOA card supports eight ports in which eight hot pluggable VOA SFP modules can be inserted. VOA SFP modules can be either bright type or dark type and can be software configured to operate in constant attenuation or constant output power mode. Attenuation is minimum during power fault in the bright type VOA, and it is maximum during power fault in the dark type. VOA card covers C band wavelength range. This card is supported in TJ1600 Type-11SR, TJ1600 Type-6SR and TJ1600 Type-2SR chassis.

Each card is half slot and a total of two such cards can be used in one slot with an optical adapter card (HCPADP02) thereby supporting 16 VOA SFP modules per slot.

Front Panel

The following figure shows the front panel diagram of the VOA card:

Front Panel - VOA

Power Specifications

Power Specifications - VOA Card

Specification

Range

Input Voltage

-48V DC

Power Consumption (maximum)

6W

Backplane Interface

The VOA card is connected via the optical adapter card with the backplane using high speed connectors and receives -48 V input from the backplane. The backplane interfaces are primarily for management and the optical traffic input ports are at the front.

Functional Diagram

Functional Diagram- VOA

Visual Indicator Details

The visual indicators on the VOA card include two LEDs, the ACTIVE and the STATUS LEDs.

Possible LED status and their significance - VOA Card

Card State

Status LED

Active LED

Card initialization: State before the card initialize is complete on card insertion.

Amber (Steady)

Amber (Steady)

Card in service: Initialization complete and card in service.

Green (Steady)

Green (Steady)

Card mis-match: Network Element has already configured the slot with some other card.

Amber

Amber

Card failed during boot up.

Red

Amber

Card failed while in-service.

Red

Green

Improper jack in of the card.

Green (Blinking)

Green (Blinking)

Hard Reset: All devices reset, FPGAs cleared and reprogrammed. Goes to initializing state next.

Amber

Amber

Soft Reset: Software is restarted, devices are reinitialized with provisioning. Goes to initializing state next.

Green

Green

SFP Port Visual Indications

SFP Port LED Status - VOA

State

Rx LED

Tx LED

SFP present with LOS.

Amber

Amber

SFP present (Tx enabled) with no Rx LOS.

Green

Green

SFP present (Tx disabled) with no Rx LOS.

Green

Amber

Card failed while in-service.

Red

Red

SFP missing

Amber

Off

SFP failed (whether provisioned, unprovisioned, LOS or no LOS).

Red

Red

NOTE: For proper LED indication, wait for at least 30 seconds before and after connecting fiber to the SFP interface on the VOA card.

Typical Specifications

Typical specifications and functionalities of the VOA card are as follows:

The following table summarizes the different parameters and its typical values:

Typical specifications of VOA card

Parameter

Units

Specification

Minimum

Typical

Maximum

Minimum channel spacing

GHz

50

100

--

Spectral range

nm

1528

--

1565

Insertion loss

dB

--

--

2.5

Attenuation range

dB

0

--

20

Input power range

dBm

-10

--

+21

VOA Type

--

Bright/Dark

Dark

Block Attenuation Loss

dB

35 (for Dark Type)

Return loss

dB

<-40

Attenuation accuracy

dB

--

--

+/-1.0

Polarization dependent loss

dB

--

--

0.3

Power consumption per module

mW

--

--

750

See also

Optical Active Cards and Units

OFA

OFA-C-S26-FG/OFA-C-S23-FG

ORA

ROADM

OPM-C-4 and OPM-C-2

MDU-16CL-C-50G

HCPADP01 and HCPADP02

FPU01