Hitachi HC4300

The Hitachi HC4300 protocol was developed by HITACHI company for communication between control stations and substations.

The physical layer is based on a SDLC standard format.

Hitachi HC4300 operates in half-duplex mode based on the master/slave principle. While one master can communicate with up to 15 RTUs, each RTU only responds to explicit requests from the master.


7 Application Layer HITACHI HC4300 Application Layer
6 Presentation Layer n/a
5 Session Layer n/a
4 Transport Layer n/a
3 Network Layer n/a
2 Link Layer n/a
1 Physical Layer SDLC framing
RS232 (V.24)

Supported Information Types

Control Direction
  • Double Command
Monitoring Direction
  • Single indication [1 Bit]
  • Single indication [1 Bit] with time tag
  • Measured value [12 bit]
  • Counter value [16 bit]

Protocol Features

  • Physical Layer

    PCM, half-duplex, SDLC frame format/synchronisation
    Baud rates up to 2400

  • Application Layer

    on-demand transmission of analog and counter values
    on-demand transmission and transmission on change of single point indications
    transmission of single point indications with time tag
    "Select before operate" transmission of commands

  • Address Space

    RTU addresses 1..15
    binary indications: 3 groups with 16 words each. Each word contains 16 bit.
    Measured values: 8 groups with 16 measured values each

Implemented Protocol Stacks

HITACHI HC4300, Master

HITACHI HC4300, Slave

Applicable Products

  • ipConvLite

    inexpensive protocol converter for standardized application

  • ipConvPBS

    Universal protocol converter with integrated PROFIBUS-DP, slave interface

  • ipConvPBM

    Universal protocol converter with integrated PROFIBUS-DP, master interface

  • ipConvPNM

    Universal protocol converter with integrated PROFINET-IO, master interface

    Available soon !
  • ipConvPNS

    Universal protocol converter with integrated PROFINET-IO, slave interface

  • ipConv

    Universal protocol converter for highest degree of flexibility


    ABBHTC, Iran

    Products: ipConv
    Protocol Stacks: HITACHI HC4300, Slave IEC 60870-5-101, Master