PCOO-3027 series optical 2:1 automatic changeover

“PROFLEX” PCOO-3027 series optical changeover is designed to protect an optical fiber link. PCOO-3027 continuously measures the optical power on it's two inputs and automatically switches the optical output to the stand-by input if the main input optical signal is lost or falls below some power level. The latching optical relay retains it's state during the power outages.

Features

• continuously measures and displays the optical power on both (the MAIN and the STBY) inputs
• independent switching threshold settings for the MAIN and the STBY inputs
• automatic and manual changeover modes
• automatic and manual changeback modes
• latching optical relay
• user-selectable delay for the changeover and the changeback actions
• currently selected input indication
• GPI outputs to control a slave device
• local and remote control of switching (from GPI and/or "PROFLEX" protocol)

Available modifications:

General description

PCOO-3027 simplified schematic:

PCOO-3027 rear panel:

The MAIN and STBY optical signals are continuously measured by means of optical splitters, the other output of each splitter is connected to the optical latching relay. The measured optical power on each channel is compared to a user-presettable threshold, below which the switching occurs. However, if the stand-by optical signal is weaker than it's threshold - no switching will occur no matter what the main signal level is. To prevent a spurious relay switching the protective user-selectable delay of 0~10 seconds is provided (SW DEL), if more than one optical glitch is detected within that interval - the stand-by input is connected to the output. The respective RETURN TIME interval protects the changeback when the main input restores (i.e. is at least 1dB over the threshold).

Technical specifications

Optical inputs/outputs

GPI

Controls

Indicators

• active input (MAIN/STBY) indication
• current optical power on each input
• operation mode (AUTO/MAIN/STBY)

Controls and management

PCOO-3027 local controls are on the frontal panel:

Buttons

• CHANGE – toggles the optical output between the MAIN and the STBY optical inputs, disables the automatic changeover mode
• AUTO – enables/disables the automatic changeover mode
• MODE – scrolls through the list of editable parameters
• UP/DOWN – toggle to edit the currently selected parameter

Indicators

• IN USE MAIN – lit when the MAIN input is provided to the optical output
• IN USE STBY – lit when the STBY input is provided to the optical output
• IN USE AUTO – lit when the automatic changeover mode is selected
• POWER MON MAIN/STBY – lit when the measured optical power (in dBm units) at the MAIN/STBY input respectively is shown at the digital display. The " - dBm" indicator is lit when the measured level is below 0dBm
• THRESHOLD MAIN/STBY – lit when the changeover/changeback threshold (in dBm units) is shown at the digital display, press the UP/DOWN buttons to edit the selected threshold
• RETURN MODE - lit when the currently active changeback mode is shown at the digital display:
  • FF - "FLIP-FLOP mode", the changeback will happen on the optical power restoration at the MAIN input
  • FO - "FLIP-ONLY mode", changeover is automatic, the changeback is manual
    Use the UP/DOWN buttons to edit the RETURN MODE setting
• SW DEL - lit when the changeover delay time (in seconds) is shown at the digital display, the UP/DOWN buttons will edit the delay time
• RETURN TIME - lit when the changeback delay time (in seconds) is shown at the digital display, the UP/DOWN buttons will edit the delay time
• FIBER LINK MAIN/STBY - the two sets of indicators for the MAIN/STBY inputs status. Three possible cases:
  • green LED is lit - an optical line is operational, the optical power is above the threshold
  • red LED is lit - an optical line is inoperational, the optical power is below the threshold and there is no optical signal
  • both LEDs are lit - an optical line is in a fault state, the optical power is below the threshold but an optical signal is present

Please, note:

The AUTO button toggles the automatic changeover mode ON/OFF. If you disable the automatic mode when the MAIN input is connected to the optical output (the IN USE MAIN indicator is lit), the PCOO-3027 operates as usual. However, if the STBY input has been selected (the IN USE STBY indicator was lit) when the automatic mode was disabled, the PCOO-3027 behaviour will depend on the RETURN MODE current setting: if RETURN MODE is set to FF, the switching tî the main input will happen after the current RETURN TIME interval, if RETURN MODE is set to FO - the switching tî the main input will not happen, use the CHANGE button to manually operate the changeover.