Decode IDM 50 Modem
Scada Modem
Utility Communications Modems

IDM 50

* A programmable modem for power utility communication network
* Multi-standard support: CCITT R.38A, R.38B and V.23
* Fully programmable via Hayes AT command set
* Specialized Line, Power Line Carrier or radio communication
* Half or full-duplex operating mode
IDM50 is a frequency shift keyed modem for asynchronous data transmission in 300-3400 Hz voice band. It uses binary frequency modulation techniques which make it highly immune to interference and noise and permit extensive voice-band communication link utilization.

The modem supports CCITT R.38A, R.38B and V.23 communication standards. Table of programmable channels depicts possible utilization of audio band. The modem can operate in half or full-duplex, point-to-point or point-to-multipoint mode, with receive and transmit channels independently set.

The modem employs advanced microprocessor technology, thus offering high service flexibility through programmable features. Software configuration is performed via Hayes AT command set. AT commands can be initiated from any terminal application using RS-232 communication interface. Additionally, for easy firmware upgrade a bootstrap loader is provided.


IDM50 is designed for use in SCADA systems mainly based upon power utility communication networks. It can communicate through specialized, private or leased lines, radio links and power lines (PLC).

Mounting Types

IDM50 is available as a desktop modem or in two different types of standard 19'' rack:
  • 1U rack with 1, 2 or 3 modems per rack;
  • 3U rack with 10,12 or 14 modems per rack and additional blank front plates covering unused slots.

    *All connectors at the rear side are accessible at the back openings.


    Type Data transmission on band share audio frequency analog medium.
    Modulation Bivalent frequency shift of the significant frequencies centered at one quarter and three quarters of the channel.
    Media LS (Specialized Line), Radio, PLC
    Mode Full duplex:
  • on same channel when modem is configured as 4W
  • on different channels when modem is configured as 2W

  • on same channel when modem is configured as 2W
  • on a half-duplex radio link or semi-duplex equipment
  • BER Better than for a signal/noise ratio of 17dB with a group delay distortion of 60% whatever the channel.
    DTE interface
  • RS-232C, DB9 (female) connector
  • Signals: DCD, RD, TD, DTR, SG, DSR, RTS, CTS, RI
  • Character length: 5-9 data bits, 1 start, 1 stop
  • RTS/CTS delay: adjustable by 1ms step within range of 40-6825ms
  • Option to switch on fail relay if DCD off
  • Option to transmit on RTS
  • Option to copy DSR to DTR
  • Configuration: AT command set at 1200 bps
  • Analog line
  • DB15 (female) connector;
  • 600Ω or high impedance with return loss < 0.2;
  • Transmission level: 0 to -32dBm, programmable by 1dB step
  • Receive level: 0 to -36dBm, programmable by 1dB step, min. -48dBm
  • Radio control: half-duplex control and squelch detection
  • Power supply 2-position screw plug type (for 2-2.5mm2 wire)
    LED indication PWR, TXD, RXD, DCD
    Power supply 36-72VDC, 25-50VAC
    Isolation Transformer up to 1500V
    Immunity to noise
  • Peak pulse noise: 100V Peak
  • Effective interference at 50 Hz: 80V rms
  • Temperature Operation and storage: -10? to +50?C
  • desktop: aluminium enclosure 112x30x170mm
  • 19'' rack: EUROCARD PCB, 160x100mm 3HE, 6T in 1U and 3U rack
  •  120VAC Models Available through DCE

    Decode IDM-100