RAD FCD-E1I E1 or Fractional E1 Access Unit with S Interface

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FCD-E1I   E1 or Fractional E1 Access Unit

RAD FCD-E1I E1 or Fractional E1 Access Unit with S Interface

  • E1 or Fractional E1 access unit
  • Four ISDN BRI "S" interface ports
  • One data port with selectable data rates: n x 56, n x 64 kbps
  • Data interfaces: V.35, RS-530, RS-449/422 or X.21
  • Optional sub-E1 drop & insert port for PABX connectivity
  • In-band remote management FEATURES
  • Dial-in option for remote out-of-band management
  • Enhanced diagnostics include:
    • User-activated local and remote loopbacks
    • Integrated BER tester
    • Fractional E1 in-band loop
  • E1 main link available with the following options:
    • Standard E1 interface
    • Built-in LTU
    • Fiber optics
  • E1 interface complies with ITU G.703, G.704, G.706, G.732, G.823
  • Stores 24 hours of E1 network performance monitoring and most recent 100 alarms
  • Relay activation upon alarm event
  • Alarm mask configurable for any alarm


  • The basic unit includes power supply, E1 main link and data port, and four ISDN "S" interface ports.
  • The E1 interface is compatible with almost all carrier provided E1 services and meets ITU recommendations G.703, G.704, G.706 and G.732. It supports either 2 or 16 frames per multiframe, with or without CRC-4. Zero suppression over the line is HDB3. The integral LTU (optional) ensures a range of up to 2 km.
  • FCD-E1I can be ordered with a fiber optic main link, which eliminates the need for an external fiber optic modem. The fiber optic link complies with ITU standards G.703, G.921 and G.956.
  • The following fiber optic interfaces are available:
    • 850 nm LED for use over multimode fiber at distances up to 5 km
    • 1300 nm LED for use over single mode fibers at distances up to 47 km
    • 1300 nm laser diode for use over single mode fibers for range up to 62 km
    • 1550 nm laser diode for use over single mode fibers for extended range up to 100 km.
  • Timeslot assignment is programmable, allowing data from the data port and from the sub-E1 port to be placed into timeslots consecutively. FCD-E1I provides additional flexibility by giving full user control over the data port timeslot allocation, without restrictions.
  • Multiple clock source selection ensures maximum flexibility for supporting different applications. The E1 main link may be clocked from the recovered receive clock, from an internal oscillator, from one of the data ports or from the sub-E1 port.
  • FCD-E1I is available as a standalone unit for desktop use. A rack-mount adapter kit enables installation of one or two units in a 19" rack.


  • The data ports interfaces can be ordered as V.35, RS-530,
    V.36/RS-449 or X.21. The ports can operate in the following clock modes:
    DCE: Transmit and receive clocks are output
    DTE1: External transmit clock is input (coming from the user DTE)
    DTE2: Both transmit and receive clocks are externally input.
  • The four ISDN "S" interfaces can be used for extending ISDN services to locations that do not support ISDN. Each "S" interface port operates in full duplex over 4-wire twisted-pair for a range of up to 1000m (3300 ft).
  • The ISDN "S" interface ports can operate in the following clock modes:
    NT Transmit clock timing is locked to the nodal timing
    TE Transmit clock timing is derived from the RX signal from the NT (ISDN switch). The unit's nodal clock can be locked on to this clock.
  • The optional sub-E1 port can be configured to work without CRC-4, while the main E1 link is working with CRC-4. This enables connection of E1 equipment not supporting CRC-4, over an E1 network that is working with CRC-4.


  • Setup, control and monitoring of status and diagnostics information can be activated via:
    • ASCII terminal connected to the async control port command line interpreter
    • SNMP management connected to the async control port.
  • FCD-E1I has an internal SNMP agent and can be controlled by any generic SNMP station or by the RADview SNMP network management application. In addition, configuration and monitoring is provided via TELNET or a dumb terminal.
  • FCD-E1I supports dial-in modem connections. These connections can be used for remote
    out-of-band configuration and monitoring.
  • In-band management can be performed by using the spare bits (SA bits) on timeslot 0 or by using a dedicated timeslot. This allows setup, monitoring and diagnostics of the remote unit. In-band access by using spare bits on timeslot 0 is possible only if those bits are passed transparently end-to-end.
  • Maintenance capabilities include user activated local and remote loopbacks at the main E1 link, sub-E1 port and data port. The user can activate a BER test for the data port. The data port responds to an ANSI FT1 in-band loop code, generated from the remote FCD-E1I in a specific bundle of timeslots allocated only to that port.
  • When operating with CRC-4, E1 network statistics are stored in memory according to RFC-1406. The statistic information may be retrieved locally through the control port.


E1 or Fractional E1 Access Unit

* Specify optional drop & insert sub-link:
S1 for E1 sub-link
~ Specify power supply:
115 for 115 VAC
230 for 230 VAC
48 for -48 VDC
& Specify data port interface:
530 for RS-530 interface
V35 for V.35 interface
X21 for X.21 interface
449 for RS-449 interface
Specify optional link interface:
LTU for integral Line Termination Unit
#+ Specify fiber optic interface:
# ST for ST connector
SC for SC connector
FC for FC/PC connector
+ 85 for 850 nm, multimode
13 for 1300 nm, single mode
13L for 1300 nm, single mode, laser diode
15L for 1550 nm, single mode, laser diode
(Default is G.703 electrical interface)

The following cables convert the 25-pin data port connector into the respective interface. Cable length is 2m (6 ft), unless indicated otherwise.

  CBL-HS2V1 to connect a V.35 DTE using DCE clock mode*
CBL-HS2V2 to connect a V.35 DCE using DTE1 clock mode*
CBL-HS2V3 to connect a V.35 DCE using DTE2 clock mode*
CBL-HS2R1 to connect an RS-449 (V.36) DTE using DCE clock mode*
CBL-HS2R2 to connect an RS-449 (V.36) DCE using DTE1 clock mode*
CBL-HS2R3 to connect an RS-449 (V.36) DCE using DTE2 clock mode*
CBL-HS2X1 to connect an X.21 DTE using DCE clock mode*
* DCE clock mode: FCD-E1I provides both transmit and receive clocks
DTE1 clock mode: FCD-E1I provides transmit clock, attached DCE provides receive clock
DTE2 clock mode: attached DCE provides both transmit and receive clocks




Figure 1. Connection of LAN, PABX and ISDN Traffic to E1 Network

Figure 2. Network Application for Multiple Remote Sites


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