Telephone Interface Board (FXS) (700-15-04)

Telephone Interface Board (FXS) (700-15-04)

Optional Telephone Interface for Mercury Interface Units (MIUs)

  • Up to 4 Telephone Interface Boards per MIU
  • Provides a standard interface for up to 4 analog telephones
  • Allows subscribers to navigate the Mercury system using a DTMF keypad
  • Can be used to access a landline at any location on the Mercury system
  • Ring-down feature enables an immediate, dedicated connection with any Mercury subscribers
  • RJ11 connectors for easy cabling
  • Port-specific input and output level adjustments
  • Software configurable
  • Customizable dial plans
Item Part Number:


The Telephone Interface Board (FXS) is an optional interface board that provides a standard interface for up to four analog telephones or other telephony devices, allowing Mercury subscribers to make and receive calls anywhere on the system.

Technical Specifications

Line Interface

Number of channels: 4 per card, Max of 4 option cards per MIU

DSP Channel usage: Programmable

Signalling Loop start

DTMF: DTMF generation for dial-out

Line Impedance: CTR21, 600R, 900R or Japan – software selectable

Return loss: >18dB 300-400Hz

Protection: “on premise” level 1 protection

Ring Trip: Min 500R, typical 800R

Ringing capability: 500R for 40Vrms into REN=3

Ring voltage: 65Vrms typical, no load

Longitudinal to metallic balance: >40dB (300-600Hz); 45dB (600-3400Hz)

Common mode rejection ratio (CMRR): >40dB 300-3400Hz

THD: <1% at 0dBm, 1kHz

Crosstalk: <-85dB (inter-channel and inter-card)

Nominal line TX level: -9dBm ± 1dB

Input level adjustment: Via software –9dB to +12dB in steps of 1.5dB

Output level adjustment: Via software –34.5dB to +12dB in steps of 1.5dB. Mute option

Freq response: 300Hz – 3200Hz ± 2dB ref to 1kHz (8kHz sampling) with all echo processing and pre-emphasis disabled hours


Line: RJ11 2 pin modular jack socket

Phone connector pinout: Pin 3 – ring (A), Pin 4 – tip (B), other pins – unused


Ring Cadence: US Ringtone

Echo Suppression

General: DSP Based adaptive filter providing acoustic & network suppression

Tail length (acoustic): 39.5ms

Tail length (network): 24ms

Echo Return Loss: 30dB typical, network and acoustic
Enhancement (ERLE)


Operating Temperature:
32° to 122°F (0° to 50°C)

Storage Temperature:
-4° to 185°F (-20° to 85°C)

Operating Humidity: 0 to 90%, non-condensing, relative humidity


5.5 x 0.67 x 8.1in (WxHxD)

(140 x 17 x 205mm)


6.0oz (170g)


MTFB: 80,000 hours

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