DN-6980:A • 05/01/2009 — Page 1 of 2
AFL-RM, AFL-TM,
AFL-RS, AFL-TS
Audio Fiber Link Modules
Voice Control Systems
DN-6980:A • C-150
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General
The AFL-TS/AFL-TM (single- or multi-mode transmitters) and
AFL-RS/AFL-RM (single- or multi-mode receivers) are Audio
Fiber Link Modules that distribute low-level audio signals via
fiber-optic media.
The AFL-TS/-TM transmitter accepts low-level audio signals
from the DVC-AO. The AFL-TS/-TM then converts the low-
level audio signals to modulated light, which is transmitted
through fiber-optic cable. The AFL-RS/-RM receiver accepts
that modulated light at the other end of the fiber-optic cable,
then converts the modulated light to low-level audio to feed
AA-30, AA-100, AA-120, or XPIQ amplifiers, or (if required) the
next daisy-chained AFL-TS/-TM.
Audio Fiber Link (AFL) modules are powered from nonresetta-
ble 24 DVC output from power supplies that are listed for fire
protective signaling service.
Applications
Audio Fiber Link modules may be used in systems where:
• The use of wire media is not possible due to security
requirements.
• Fiber-optic cable is already installed and available for low-
level audio distribution.
• Significant distances between DVC-AO and remote ampli-
fier cabinets dictate the use of fiber.
• High-intensity electromagnetic fields of audible frequencies
could be coupled to low-level audio over wire.
• Both distance and physical location of remote cabinets
require the use of star topology.
Up to 50 AFL transmitters maybe be connected to the output
of a DVC-AO.
A maximum of ten amplifiers may be fed from AFL receiver
output; and a maximum of ten AFL transmitters may be fed
by a single AFL receiver.
The maximum series connection of audio fiber links is two
AFL transmitters/receiver pairs deep.
APPLICATION NOTES:
• A system requiring many fiber links may also require larger
batteries and external chargers. Please refer to the
POWER REQUIREMENTS section on page 2.
• AFL transmitters should be powered by the 24 VDC UL-
listed power supply connected to the same reference (bat-
tery negative) as the audio signal source (DVC-AO, AFL
receiver).
• Class A low-level audio riser cannot be implemented when
using AFL modules.
• Any combination of up to 50 AFL transmitters and AA-30,
AA-100, and AA-120 series amplifiers may be connected to
the output of any one DVC-AO. All of the AFL-transmitters
must remain in the same cabinet as the DVC-AO.
• Once audio system installation is complete, the audio gain
level must be adjusted. See Installation Document 52230
for instructions.
Installation
The AFL transmitters or receivers may be mounted in a CHS-4
or CHS-4L chassis, which in turn mounts into a CAB-3 or
CAB-4 Series cabinet. When mounting AFL modules on the
CHS-4 and CHS-4L, adequate clearance above the board is
required. Mounting AFL modules onto the outer position of the
CHS-4 is possible only if the AFL board is mounted with com-
ponents facing inward. AFL modules attach to CHS-4 and
CHS-4L chassis via screws to PEM standoffs or studs.
FIber Optic Link
The attenuation of fiber-optic cablins between the AFL trans-
mitter of receiver must not exceed a 10 dB limit. See Installa-
tion Document 52230 for formulas to establish limits in the
system design stage. The actual attenuation can be measured
end-to-end with standard fiber-optic test equipment, using a
signal wavelength of 850 nanometers.
The following are supported by Audio Fiber Link:
•Connectors: ST®-style
•Fiber type: multi-mode for AFL-TM and AFL-RM; single-
mode for AFL-TS and AFL-RS.
•Core size: 62.5/125 micrometers for multi-mode; or 9/125
micrometers for single-mode.
•Wavelength: 850 nanometers for multi-mode; or 1300
nanometers for single-mode.
•Maximum attenuation of fiber-optic link between AFL-TS/-
TM and AFL-RS/-RM cannot exceed 10 dB.
