• imux2000MDACS

Product Description

Designed for harsh environments, the new IMUX 2000 T1/E1 MDACS creates a new class of Intelligent Multiplexer with features such as Digital Access Cross-Connect Switch, built in CSU functionality and DS0 squelching capability.

The unit provides full featured, Drop-and-Insert capability for each voice frequency circuit or any signal that can be transmitted in a DS0 channel. The multiplexer has electrical and a wide variety of optical fiber (both singlemode and multimode) interfaces to simplify system configuration. Channel cards are available for voice, data, telemetry, teleprotection, video and ethernet applications.

The IMUX 2000 T1/E1 MDACS supports many types of network layouts such as Spur, Hot Standby and Ring topologies. The IMUX 2000 T1/E1 MDACS is both hardware and software configurable. The unit offers the ultimate network management system. It operates in a Windows™ point-and-click environment and provides network visibility from any node which allows for remote provisioning, monitoring and alarm reporting.

The IMUX 2000 T1/E1 MDACS is compact, modular in design and compatible with previous generations of RFL Multiplexers. For a product that meets and exceeds your telecommunication needs, advance into this new class of hardened multiplexer and make the Intelligent choice, the IMUX 2000 Intelligent T1/E1 MDACS.

Substation Hardened

The IMUX 2000 T1/E1 MDACS is designed for harsh environments and has a wide temperature range of -20°C to +65°C. It meets the IEEE/ANSI standards C.37.90-1989, C.37.90.1 and C.37.90.2 for SWC, fast transient and EMI.


The IMUX 2000 T1/E1 MDACS provides enhanced reliability by offering optional redundant power supplies.


The IMUX 2000 T1/E1 MDACS is designed to handle time sensitive applications such as Protective Relaying. The Drop-and-Insert through-channel delay is less than 25 microseconds. The IMUX 2000 T1/E1 MDACS has an average reframe time of less than 25 milliseconds.

DS0 Squelching

The IMUX 2000 T1/E1 MDACS has the ability to squelch (turn off) the output of a channel module in the Multiplexer upon loss of synchronization. This feature provides security against false tripping on 4-wire analog transfer trip channels and older digital equipment (with limited error checking) during loss of sync and protects against ‘pink’ noise conditions, which result from cross-talk or the frame search. This feature is ideal for preventing false tripping due to system malfunction.

CSU Functionality

The IMUX 2000 offers a built in CSU functionality that meets applicable standards for protection including FCC Part 68 approval for direct connection into the Public Switched Telephone Network (PSTN). When enabled, the unit will respond to generated loopback codes compliant to either ANSI T1.403 or AT&T TR 54016. It will also maintain and allow local and remote retrieval of performance measurements in accordance with either ANSI T1.403 or AT&T TR 54016.

Modular Design

The IMUX 2000 incorporates a midplane motherboard design. Channel modules plug into the front of the unit, and matching module adapter for I/O connections plug into the rear. This eliminates the need for internal chassis wiring when adding new channel cards, simplifying the upgrade.


The IMUX 2000 T1/E1 MDACS offers the ultimate Network Management system which operates in a Windows TM point and click environment. The optional SNMP based management reporting software can be used when integrated as part of a larger enterprise system. Network visibility is available from any node which allows remote provisioning, monitoring and alarm reporting. Intuitive graphical user interface with color coded DACS maps.

Fiber Optic or Electric Interfaces

The IMUX 2000 can be equipped with either electrical T1/E1 interfaces or Optical Interface Adapters (OIA’s). The electrical T1 interface is equipped with Line Build-Out (LBO) networks for operation of up to 6,000 feet from the DSX. The OIA’s are available in a wide range of multimode, single-mode, LED or laser combinations to accommodate 1300nm and 1550nm wavelengths.

Channel Interfaces

A wide range of interfaces unique to the utility and the transportation market is offered. It also offers a wide range of Voice and Data, Status, Telemetry, Ethernet, Transfer Trip and Video channel interfaces to meet most communications requirements.

Fast Restoration

When applied to diverse communication routes, such as Ring or Hot-Standby networks, the IMUX 2000 is capable of switch times programmable down to 1 millisecond.

Diverse Networks

The IMUX 2000 T1/E1 MDACS supports many types of network layouts such as Linear, Spurs, Hot-Standby and Ring topologies. It is also designed for operation over SONET/SDH networks taking into consideration the critical time-delay issues associated with Protective Relaying.

SONET and SDH Applications

Protective Relaying can finally be applied over non-proprietary SONET/SDH equipment. With emphasis placed on rapid break healing, the IMUX 2000 T1/E1 MDACS addresses the critical time issues associated with Protective Relaying making it the ideal and Intelligent choice when interfacing to SONET/SDH networks. The IMUX 2000 T1/E1 MDACS bridges the gap between SONET/SDH and substations providing DS0 gateways onto the network. Also, through its own switching techniques, can overcome the longer switch times and unequal channel delay issues associated with SONET/SDH.

Digital Access Cross-Connect Switch

Functionality provides full cross-connect capability as well as a reliable level of system restoration. The IMUX 2000 T1/E1 MDACS enables the termination of up to four [4] T1/E1 ports while also providing full DS0 Time Slot Interchange capability. System restoration is accomplished through the use of alternate DS0, Time Slot Interchanged maps. The alternate maps are predetermined and pre-programmed through our user friendly Network Management Software. An alternate DS0 map is invoked automatically upon detection of T1/E1 failures (e.g. AIS, Loss of Frame, excessive BER). The time necessary to switch to an alternate map, upon detection of failure, is programmable down to 1 millisecond.

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  • DSX-1 interface per ANSI T1.102-1993


  • 1.544 Mbps per ANSI T1.102-1993
  • (Transmit ± 30 PPM using internal timing)

Transmit Pulse Shape:

  • Per ANSI T1.102-1993


  • Extended Superframe (ESF) per AT&T 62411, D4/ Superframe (SF) per AT&T 43801

Line Codes:

  • Bipolar with 8 Zero Substitution (B8ZS) & Alternate Mark Inversion (AMI)

Output Impedance:

  • 100 Ohms nominal per ANSI-T1.102-1993

Reframe Time:

  • Less than 25 milliseconds.


Primary Timing:

  • Internal, External, Loop

Secondary Timing:

  • Internal, External, Loop
  • (Automatically enabled in case of primary timing failure.)

Timing Input/Output:

  • T1: 1.544 Mbps, (RJ11 connector)
  • E1: 2.048 Mbps, G.703 (RJ11 connector)



  • -20°C to +65°C operating

SWC & Fast Transient:

Power supply, alarm contacts, pilot wire interface & transfer trip interface meet the requirements of ANSI C.37.90-1989 & ANSI C.37.90.1. EIC 1000-4-2:1995, IEC 1000-4-3:1997, IEC 1000-4-4:1995, IEC 1000-4-6:1996, IEC 1000-4-8:1994, DD ENV 50204:1996.


  • The chassis & modules meet ANSI C.37.90.2.


  • 0-95% Non-condensing

Shock & Vibration:

  • The chassis and channel modules shall meet requirements of IEC 255-21-2 and IEC 255-21-1.



  • Conforms to ITU G.703


  • 2.048 Mbps ± 50 PPM input and output

Jitter Tolerance:

    • Exceeds ITU G.823


        • Greater than 18 dB at 40Hz


            • Frame format per ITU G.704 in 30-channel and 31-channel modes.

Line Codes:

                • HDB3 (High Density Bipolar, Order 3 per ITU G.703,or AMI (Alternate Mark Inversion)


                    • 75/100 ohm BNC connector or RJ-48 connector for twisted pair.

Frame Synchronization:

                      • Average reframe time non-signaling DS0’s: 0.6 ms
                      • Multi-frame based signals (Signaling): 5ms


Propagation Delay (DS1/E1 through Delay):

  • DACS: 1 to 3 frames average (250 msec) for each pass through.

Switch Time:

  • DACS DS0/T1, DS0/E1 Alternate Maps: Programmable down to 1ms.

Test and Diagnostics:

  • Loopbacks: Remote, Local and Analog DS0 & Ds1/E1>/li>
  • Test pattern: PRBS pattern generation/detection.
  • 16-bit loop-up and loop-down code generation and detection.



  • Height: 5.25” (144 mm)
  • Width: 19” (483 mm per EIA RS-310)
  • Depth: 14.50” (370 mm)
  • Available in 23" width mounting.


  • 15 lbs (6.8 kg). for typical fully loaded shelf.



  • Remote monitoring, configuration and alarm reporting.

Local access:

  • Switch settings

Remote Access:

  • RS-232C port
  • Optional 10 BaseT Ethernet Interface


  • All shelves can be equipped with a secondary plug-in power supply for redundancy.

Input Voltage: Range:

  • 24 Vdc 19 to 29.0 Vdc
  • 48/125 Vdc 38 to 150 Vdc
  • 250 Vdc 200 to 300 Vdc
  • 120 Vac 90 to 130 Vac
  • 220 Vac 180 to 265 Vac


Emitter Wavelength Fiber System Gain

  • LED 1300 nm MM 25dB (12mi; 19km)
  • LED 1300 nm SM 18dB (17mi; 27km)
  • Laser 1300 nm SM 36dB (37mi; 62km)
  • Laser 1550 nm SM 30dB (56mi; 90km)
  • Laser 2mw 1550nm SM 39dB (70mi; 113km)


Status Monitoring:

  • Constant monitoring of equipment with alarm reporting.

Alarm Types:

  • Alert, cautionary conditions that do not prevent multiplexer operation. Alarm, conditions that directly affect multiplexer operation.


  • Front panel indicators and alphanumeric display, RS- 232 port for remote access and interrogation, form C relays for shelf alarm and alert.


  • T1: Line, Equipment and Payload
  • E1: Line and Equipment


Voice Units:

  • Type I, II, III & V E & M signaling
2W Foreign Exchange
  • Loop or ground start signaling
  • Automatic ring down option
  • Type I, II, III & V E & M signaling
  • Point-to-point and multi-point
4W FXO and FXS
  • Channel addressing for added protection
  • 2713Hz detection loopback mode
  • Optional SWC rated connection for analog teleprotection


  • 2W party line voice circuit over a 64 kbps channel
  • DTMF signaling
  • Uses a regular 2W phone

Data Units:

Low Speed Data
  • RS-232 interface Async. and Synchronus
  • RS-422 interface
  • RS-485 interface 2 or 4 wire
  • Sub-rate multiplexing
  • Point-to-point and multi-point
High Speed Data (56/64 kbps rates)
  • RS-449, V.35, X.21 and G.703, RS-530
  • Channel addressing for added protection
  • ANSI C37.94 optical interface
High Speed Data (N x 64 kbps Rates)
  • N = 1 to 24 64 kbps
  • RS-449 & V.35 interfaces
  • ANSI C37.94 optical interface
Office Channel Unit Data Port (OCUDP)


Contact Input/Output
  • 16 input
  • 16 output
  • 8 input / 8 output

Teleprotection Units:

Modular Teleprotection System
  • Application: DTT, POTT, PUTT, DCB & DCU
  • Four independent bidirectional function
  • Solid state or relay output
  • Channel delay measurements
  • Sequence of events log
  • Channel addressing for added protection
Analog Telemetry
  • Transport of telemetry voltage or current
  • Bus voltage remote synchronizing application


  • IP connectivity
  • LAN / WAN interconnect
  • 10 BaseT Ethernet learning bridge
  • Support half or full duplex
  • IEEE 802.3


  • NTSC or PAL analog video signal transport
  • ITU H.261 compression algorithm
  • 1-20 frames/second
  • 64 to 1536 Kbps bandwidth
  • 352 x 288 resolution


  • WindowsTM based PC NMS
  • Access from any node for full system provisioning, monitoring and diagnostics
  • Alarm logging and time stamping
  • RS-232 craft interface
  • Optional faster NMS communication using a single
  • 64 kbps channel
  • Optional 10 BaseT Ethernet Interface
  • Optional interface for SNMP manager

Network Diagram Example

A typical utility/traffic system solution made up of two SONET/SDH rings as the communications backbone.

Above is an example of a typical utility/traffic system solution. It is made up of two SONET/SDH rings as the communications backbone. The IMUX 2000 T1/E1 Multiplexers are configured to work in a Point-to-Point, Star and Stand-Alone Linear topology over the SONET/SDH system.

The IMUX 2000 carries RTU and phone circuits form several substations to the operations center. It also carries current differential relay data between substations.

The IMUX 2000 carries roadside signals, transmission data from vehicle loop detectors, compressed digital video, camera control, toll collection information, status and alarm reporting, voice and data traffic signal controls back to the operations center.

Support (Documents & Downloads)

Please visit Operating Manuals or Product/Software Downloads to download relevant files. Requires RFL Customer Account.

Files Available in the Customer Area

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Utility Industry Solutions

Utility industry and electric utility white papers by RFL providing communications and protection solutions to today's challenges, such as migrating data from leased lines.

Helping Utilities Move Forward in IP Migration

Multipoint-to-Multipoint Protective Relaying Signaling Using Digital Communications and Built-In Logic

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