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TTMX Teleprotection Terminal

Fast and Secure Teleprotection for Transmission
and Distribution Grids

Protecting your critical assets after a fault is crucial to maintaining power system stability and safety. Existing technologies are becoming harder to implement with telephone companies suspending their connection leases.

What’s need is a standards-based communications solution that is simple to implement, provides fault protection in harsh operating conditions and provides the reliability needed to address teleprotection, including Direct Transfer Trip, Permissive Transfer Trip, blocking and unblocking applications.

What is TTMX?

TTMX Is a Universal Teleprotection Terminal (TT) Multiplexer (MX) for critical and time sensitive inter-substation communications
GE Lentronics Teleprotection terminal provides:

  • Secure and Dependable communications: Built on layers of redundancy and substation hardened to ensure reliable operation within harsh substation environments.

  • Flexible and Scalable platform: Single or multiple digital interfaces supporting fiber-optic or Copper connections to microwave systems. Modular and hot-swappable interface units.

  • Simplified and Secure: Reuse of field proven 'JungleMUX/TN1U/TN1Ue' SONET/SDH technology offering over 28 years of Teleprotection experience across over 300 utilities world-wide.

  • Certified to IEC 60834-1 for assured teleprotection performance.


Additionally, the TTMX provides communication monitoring & management. This allows an operator to assess essential parameters like trips, device health, status of the link, settings, and alarms from a remote location.


TTMX Benefits

  • Removes dependency on a public telecommunications platform

  • Creates communication redundancy on multiple interfaces DS0/E1

  • Takes advantage of dedicated NMS or optional integration with an SNMP based platform

  • Improve user access security through LDAP / Active Directory user authentication

  • Strengthens confidentiality with optional encryption module

  • Flexible configuration of trip commands (Site-to-site / Site-to-multiple sites)

  • Suitable for deployment in all T&D substations requiring 2/4/8/12 commands per line

  • Factory-staged and tested for simplified field deployment

The TTMX platform offers 15 shelf slots with capability of adding optional expansion chassis. Compact digital access controllers offer four E1 interfaces to support fiber-optic or copper connections when connected to a higher-order transport system (microwave/SDH/MPLS).

TTMX offers a whole spectrum of modular options flexibly added to base platform. The solution is powered through 48/130 vDC station batteries with a bank of modular and hot-swappable interface units, available in the following options:


Base Teleprotection platform

  • Chassis

  • Power supply

  • CDAX



Channel Options

  • 2/4 Wire VF


  • RS 232

  • PTM Data

  • G.703 Data

  • NX64 Data (Optical & Electrical)

  • Contact I/O

  • Ethernet (64 – 768kb/s)


NMS & Security Options

  • NMX module

  • VistaNET element manager

  • Advanced NMS


Typical Configurations

P2P Configuration – Direct Fiber Interface

Simplest configuration—point-to-point over a dedicated fiber connection.

P2P Configuration – Established Link

With a high capacity point-to-point established link, such as a Multiplexer or Microwave, you can connect the TTMX to standard interfaces.

P2P Configuration – Transport Media Redundancy

With two transport media options available, the TTMX can provide a redundant solution.

P2P Configuration – Multi-terminal

Add/Drop flexibility provides point-to-point connectivity between any two sites on the network.


What is the CDAX ?

CDAX is the E1 interface card on the Lentronics Teleprotection platform, operating as a Compact Digital Access X-connect (CDAX)


Supports configurable drop-port modes

  • Channelized E1

  • Channel bus (CBUS)


Integrated 64 kbps level cross connect

  • Grooms and consolidate 64 kb/s to/from multiple E1s or CBUS ports

  • Hairpin 64 kb/s traffic between E1/64 kb/s signals
















Direct Transfer Trip (DTT) Unit
B86441-42 DTT-Tx/Rx UNIT


Transmit Functions

  • 2 Transmit commands

  • End-to-End trip time <3ms

  • Dual keying loops for improved dependability

  • Continuous integrity monitoring

  • Spurious trip immunity (software)

  • Transmit Minimum Trip Time and Trip Extension Time (software adjustable)

  • “Active Tripping” contacts for local monitoring (SER)

  • BC-96 Code format for high dependability and security

  • Form C alarm relay

  • Keying loops operate 48, 130, 250 VDC station battery

  • Adjustable spurious trip immunity, 1ms increment to 20ms

  • Two firmware images, active and standby


Receive Functions

  • 2 Receive commands

  • Main trip output

    • Dual series drivers for trip output security

    • Continuous integrity monitoring

    • 1A, 150 VDC output relays (continuous)

  • Aux trip output @ same rating

  • Receive Minimum Trip Time and Trip Extension Time (software adjustable)

  • Immune to single component failures (no false trip)

  • Form-C alarm relay for unit and per loop Form-C relay for port monitoring

  • Dielectrically isolated outputs for SWC immunity

  • RFI immunity


DTT signals connected to the relay can be tested by a dedicated test panel (B86429) which allows complete end-to-end testing without disconnecting the protection relays.

B86466 DATA-G703 Unit

  • Synchronous data transmission at 64 kb/s

  • G.703 Interface with codirectional timing

  • Visual indication of data port activity

  • Provides “Yellow” alarm to help troubleshooting

  • Circuit addressing

  • Supports local loopback, line loopback, local and line loopback

  • Built-in PRBS generator and analyzer

  • Form-C alarm relay

B86464 DATA-NX64F Unit

  • Provides an interface for interference-free intra-substation data link between TTMX node and Relay (high RFI immunity)

  • Complies to IEEE C37.94 Standard

  • Operates with up to 2 km long multimode duplex fiber (50µm or 62.5µm) using ST connector

  • Provides “Yellow” alarm to help troubleshooting

  • Alerts for loss of either fiber

  • Supports 64 kb/s, 128 kb/s,… 768 kb/s data transmission (software configurable)

  • Visual indication of data port activity

  • Circuit Addressing

  • Supports local, line and local+line loopbacks

  • Built-in PRBS generator and analyzer

  • End-to-End compatible with 86464-01 unit (V.35)

B86464 DATA - NX64 Unit

  • Synchronous data transmission at rates from 64 kb/s to 768 kb/s in increments of 64 kb/s

  • V.35 Interface or 10/100Mbps Ethernet

  • Visual indication of data port activity

  • Supports clock polarity inversion

  • Software configurable as DCE or DTE

  • Internal or External transmit clock timing

  • Circuit Addressing

  • Supports local loopback, line loopback, local+line loopback

  • Built-in PRBS generator and analyzer

  • IN and OUT control lines (all local)


86448 DATA-LS Unit

  • Supports point-to-point RS-232 asynchronous data circuits

  • Configured for one, two or four active data ports per card

    • Maximum baud rates of 38.4 kb/s, 19.2 kb/s or 9.6 kb/s

  • All data ports accept sub-multiple rates of the configured Maximum Baud Rate (MBR / 2n, n=0,1,2…)

  • Visual indication of data port activity

  • Supports local loopback, line loopback, local + line loopback

  • Four Control Lines accompany data ports

  • Built-in PRBS generator and analyzer for testing individual data circuits

B86445-32 2W VF FXS UNIT (2-Channel)

  • Software adjustable VF levels in 0.1 dB steps

    • -9.5 dBm to +5.0 dBm (Transmit)

    • -15.0 dBm to +5.0 dBm (Receive)

  • Supports Loop Start, Ground Start and PLAR signalling applications

  • Selectable Line Impedance and Network Build-Out Capacitance (software only)

  • Bantam jack allows access to VF signal

    • Programmable for “Splitting” or “Bridging”

  • Loopback commands for VF testing

  • On-board ringing generator & Talk Battery


B86445-42 2W VF FXO UNIT (4-Channel)

  • Software adjustable VF levels in 0.1 dB steps

    • -10.0 dBm to +3.0 dBm (Transmit)

    • -12.0 dBm to +2.0 dBm (Receive)

  • Supports Loop Start and Ground Start signaling

  • Selectable Line Impedance (software only)

  • Bantam jack allows bridging access to any of the four VF signals

    • NOTE: VF tests require presence of loop current

  • Loopback commands for VF testing

B86444 -08/-28 4W VF UNIT (1 or 4-Channel)

  • 4WVF circuits, with Type I-V E&M

  • Transmit and Receive levels software adjustable in 0.1 dB steps

    • -17.5 dBm to +6.5 dBm (Transmit)

    • -11.0 dBm to +10.0 dBm (Receive)

  • Custom signal pattern

  • Test features:

    • Local and Line Loopbacks

    • Synthesized 1 kHz tone can be sent to far or near end for test purposes

    • Forced off-hook state on E-lead at near or far end

  • Two firmware images, active and standby


VistaNET™ EMS for GE Multiplexers

  • A Windows PC/Server-based NMS that provides 24/7 monitoring, configuration and administration of your Teleprotection Terminal Multiplexers (TTMX)

  • Interfaces to GE’s advanced NMS solution via SNMPv1, 2c and 3 offering security and confidentiality

  • Connectivity to the TTMX network can be serial or Ethernet


NMX Unit

NMX units enables Ethernet-based connectivity for Network Management traffic between VistaNET and the TTMX hardware. The NMX unit can be optionally additionally secured through a TLS-based encryption module.

Ethernet connectivity for NMS


Optional redundant NMX unit at an alternate location is possible. VistaNET monitors and controls the network through both the nodes and chooses primary / back-up dynamically.













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