Sistem Interlocking Len-02 (SIL-02)



  • High operation capability
  • Competitive price
  • Safety priority
  • Upgradable System
  • Comply to local requirements


Len Interlocking System (SIL) is a product of PLC based Interlocking system developed by PT Len Industri.SIL is used as Interlocking Processor to control outdoor equipment operation such as light signal, track circuit, point machine, etc


SIL is developed as an alternative solution for railway interlocking system especially for Indonesian railway. SIL operation stresses the importance of safety, reliability, availability as well as easy maintenance.



  • Simple and Compact
    The design fulfills the main function requirements, effective and compact in size.
  • Low Cost
    The system requires low cost in development, assembling, operational and maintenance.
    SIL developed mostly using local resources; therefore the components and spare parts are easy to get at low price.
  • User Friendly
    Technical and non-technical design based on operational requirements at various conditions in Indonesia.
  • High Capability
    Capability to control wide range of condition from small station to the complex one. Flexible in layout development as well as operational function at stations.
  • Full Electric Interlocking
    Support all kind of outdoor equipment with NX (Entrance Exit) operation. Equal with standard Signalling Interlocking Processor (VPI, SSI or Westtrace).
  • Fail Safe
    Designed for high safety level, comply with signaling system requirements.
  • High Reliability
    By using industrial standard components, the system is very reliable.
  • High Availibility
    Len Interlocking System has been proven to work 24 hours/ 7 days a week for several years in a station without the necessity to shutdown the system.




  • Independent Station Interlocking
    One interlocking for each station, based on typical condition of railway stations in Indonesia.
  • Centralized I/O
    I/O modules are centralized and not assembled in wayside case in order to secure and protect the modules.
  • Interface Relay Based
    Using relay interface to control outdoor equipment in order to isolate and protect the system from lightning and high voltage induction.
  • Vital Data Application Software
    Data logic functions depend on stations layout.
  • Vital System Software
    Basic logical vital functions such as start up, initiation, shutdown, data exchange & compare, fail safe procedure & system diagnostic.



  • Dual channel PLC
    To read inputs, data processing and outputs.
  • Data exchange & mutual checking
    Data exchange between channel and mutual checking.
  • Self check & fault diagnostic
    Checking internal system conditions especially output terminals.
  • Failsafe procedure
    Failsafe reaction when data inconsistence or internal failure detected.