FXS Blades

The FXS blade (referred to as Module in the device's management interfaces) provides the FXS port interfaces. Each blade provides three FXS port connectors - 50-pin Telco connector (Centronics type). Each connector provides 24 FXS interfaces and therefore, each blade provides up to 72 FXS interfaces (3 x 24 FXS). The device can be housed with up to four FXS blades thereby, supporting up to 288 FXS port interfaces (4 blades x 72 FXS). The FXS blades are available as spare parts. For replacing FXS blades, see Replacing the Fan Tray Module.

Each FXS blade provides a LED on the front and rear panel, as described in FXS LEDs.

FXS Blade Showing Three FXS Telco Connectors

The chassis slot assignment for the FXS blades is shown in the following figure (front panel). Note that the slot labels (S1, S2, S3 and S4) are located on the rear panel.

Chassis Slot Assignment for FXS Blades (Front Panel)

The FXS channel (port) number range of each FXS connector on an FXS blade is indicated by the labels (FXS 1-24, FXS 25-48, and FXS 49-72) located on the rear panel above the FXS blades, as shown in the following figure:

FXS Blades and FXS Channels per FXS Connector (Rear Panel)

The following table lists the specifications of the device's FXS ports.

FXS Port Specifications

Specification	Description
Analog Lifeline (PSTN Fallback)	The FXS blade supports analog lifeline (PSTN Fallback). For more information, see Connecting the FXS Analog Lifeline.
Interface Type	FXS connection via 50-pin CHAMP connector
FXS Signaling Formats	In-band signaling DTMF (TIA 464B)
FXS Loop Impedance	Up to 1500 ohm (including phone impedance)
Off-hook Loop Current	■ 25 mA (maximum) on all ports ■ 35 mA (maximum) on the first (1) and last (24) ports per FXS connector. In other words, it applies to up to six ports per FXS Blade. This applies to emergency / elevator phones.
Ring Voltage (Sine)	■ 54 Vrms ■ 80 Vrms on six ports per FXS Blade (for emergency / elevator phones) Note: ■ Balanced ringing only. ■ Simultaneous ringing of 288 phones (72 per FXS Blade given REN 3 load)
Ring Frequency	25-100 Hz
Maximum Ringer Load	Ringer Equivalency Number (REN) 3
Caller ID	Bellcore GR-30-CORE Type 1 using Bell 202 FSK modulation, ETSI Type 1, NTT, Denmark, India, Brazil, British and DTMF ETSI CID (ETS 300-659-1)
Polarity Reversal / Wink	Immediate or smooth to prevent erroneous ringing
Metering Tones	12/16 KHz sinusoidal bursts; generation on FXS
Distinctive Ringing	By frequency (15-100 Hz) and cadence patterns
Message Waiting Indication (MWI)	DC voltage generation (TIA/EIA-464-B); V23 FSK data; Stutter dial tone