Audio Line Level 2Ch Plus Doorbell In

Model #: FOI-2981 | FOI-4982 | FOI-2983

FOI-2981 | FOI-2982 | FOI-2983

The FOI-2981, FOI-4982, and FOI-2983 all provide complete electrical isolation for audio communications. A typical link consists of either an FOI-2981 or an FOI-2983 at one end of the network transmitting optical signals to an FOI-4982 at the other end of the network with a single fiber optic cable.

Typical Application

  • Input A: voice announcements
  • Input B: background music
  • Input C: dry contact for doorbell (must be supplied by customer) A doorbell buzzer is generated when this input is grounded.

Order of Precedence

  • A (highest – overides B and C)
  • C (overides B)
  • B (lowest)

The unit can be used in areas of high electrical noise or in and out of RF shielded enclosures. The fiber optic cable is not susceptible to interference caused by impulse noise, crosstalk, or EMI. Privacy of communications is also enhanced because the fiber optic cable does not radiate any emissions. In addition, fiber optic cable offers much longer transmission distances than copper wiring. Multimode optics on the units can extend the distance to 2km.

Flexible Mounting and Powering Options

The FOI-2981, FOI-4982 and FOI-2983 are part of the FOI line of products designed for ruggedized mil applications. They are housed in the familiar FOI shielded can enclosure. For standalone applications the FOI-2981 and FOI-2983 can be powered by adding a PSQ‐2909 AC supply or a PSQ‐2920 DC power supply (not included) and the FOI-4982 can be powered with a PSQ‐4909 AC supply or a PSQ‐4920 DC supply. Optionally, up to 8 FOI units can be mounted on CMA chassis adapters and installed in an RMC‐3101 or RMC‐2101 rack mount chassis. The units are powered redundantly by a common back plane connection.

FOI-2981:Optical Transmitter

  • 2 Audio Inputs
  • 1 Doorbell Input

FOI-2982:Optical Receiver

  • 2 Audio Outputs (8 Ohm and 600 Ohm)

FOI-2983:Optical Transmitter

  • 2 Audio Inputs
  • 1 Doorbell Input

(1 Audio Input Used for 70V Distribution Systems)

ELECTRICAL SPECIFICATIONS - FOI-2981
Power Requirement 9 VDC @ 275 mA
Frequency Response 100 Hz - 8 kHz ± 3 dB
Input Level for A and B
Minimum
Maximum
50 mV RMS Adjust
Doorbell Operation for C A doorbell buzzer is generated when this input is grounded.
Priority Scheme A (highest - overides B and C) C (overides B) B (lowest)
Interface Connector A, B and C RCA Type Phono Jack
ELECTRICAL SPECIFICATIONS - FOI-4982
Power Requirements 9 VDC @ 275 mA
AUDIO OUTPUT 8 OHM Interface Connector 2-Conductor 1/4” Enclosed Telephone Jack (Balanced Output)
AUDIO OUTPUT 600 OHM Interface Connector RCA Type Phono Jack
ELECTRICAL SPECIFICATIONS - FOI-2983
Power Requirement 9 VDC @ 275 mA
Frequency Response 100 Hz - 8 kHz ± 3 dB
Input Level for A 70 V line transformer, 50mW, 100 kO
Input Level for B
Minimum
Maximum
50 mV RMS Adjust
Doorbell Operation for C A doorbell buzzer is generated when this input is grounded.
Priority Scheme A (highest - overides B and C) C (overides B) B (lowest)
Interface Connector A 3-Conductor 1/4” Enclosed Telephone Jack
Interface Connector B and C RCA Type Phono Jack
PHYSICAL SPECIFICATIONS - All
Case
Length
Width
Height
Weight
FOI-2981 & FOI-2983 Size 2
4.5 in (114 mm)
1.312 in (33 mm)
2.562 in (65 mm)
2 lb (0.9 kg)
FOI-4982 Size 4
4.5 in (114 mm)
1.453 in (37 mm)
2.562 in (65 mm)
2 lb (0.9 kg)
OPTICAL CHARACTERISTICS - All
Fiber
Size
Max Distance
Wavelength
Output Power
Multimode
62.5/125
2 km
820 nm
-18 dBm
oi_FOI-2981
Standalone Operation  
PSQ-2909  Standalone AC Power Supply
PSQ-2920 Standalone DC Power Supply
WMA-3002 Wall Mount Adapter
WMA-2001 Wall Mount Adapter with ST Optical Patch
Chassis Mounting  
RMC-2101 2U, 19" Rack Mount Chassis. Holds up to 9 FOI Modules
CMA-2001 Chassis Mount Adapter for RMC-2101 Chassis. (1) per FOI Module required
PSM-2010 Spare Power Supply for RMC-2101
RP2 16 Channel Modular Bolt-On Connector Panel for RMC-2101
  
RMC-3101 3U, 19" Rack Mount Chassis. Holds up to 9 FOI Modules
CMA-3002 Chassis Mount Adapter for RMC-3101 Chassis. (1) per FOI Module required
PSM-3010 Spare Power Supply for RMC-3101
Industrial Solutions
RMC-3700  Environmental Enclosure for FOI Modules
CMA-3002 Chassis Mount Adapter for RMC-3101 Chassis. (1) per FOI Module required
PSM-3010 Spare Power Supply for RMC-3101

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