CYGNUS 835 V21/V23 to E1 Converter

CYGNUS 835 is ideal for use in Digital Axle Counter interconnection applications in Railway signaling. It allows Digital Axle Counters with ITU-T V.21 or V.23 compatible communication interface to connect to an E1 channel. Its built–in Copper Bypass facility with automatic changeover provides enhanced reliability for critical applications by automatically diverting V.21/V.23 traffic to a standby 6-Quad Copper Circuit in case the E1 link fails or degrades or if the CYGNUS 835 units gets powered off for some reason.


  • CYGNUS 835 converts ITU-T V.21/V.23 signals to E1 format, for transport on a 2.048 Mbps E1 stream via an ITU-T G.703 compatible interface.
  • User interface is compatible with ITU-T V.21/V.23 and allows transport of full-duplex voice band analog modem signals over a 2-wire interface. Compatible with all standard Digital Axle Counters used by Indian Railways.
  • Automatic Changeover to 6-Quad bypass copper circuit: if (a) the E1 link fails (b) E1 link degrades, or (c) if the CYGNUS 835 unit is powered off for some reason.
  • Bypass link checking: The bypass 6-Quad Copper circuit is continuously checked even when the E1 link is being used
  • Event logs: Time stamped record of events such as Unit Power On/Off, E1 Link Up/ Down, Bypass Link Up/Down, E1 Line Error Rate threshold exceeded accessible via Supervisory Port.
  • Potential Free Alarm Relay Contacts to indicate Alarms such as Unit Power Down, E1 Link Down, E1 Error Rate Threshold exceeded, Bypass Link Down. May be connected to Data Logger network for centralized monitoring of alarms.
  • SMS Alert: Facility to send SMS messages to specified phone numbers on specific alarms.
  • Operate from either 24 VDC or 48 VDC power supply.
  • Industrial temperature grade components.
  • 19 inch, 1 U height rack mountable

Application Diagram