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.
HITACHI HC4300 Application Layer
SDLC framing RS232 (V.24)
Supported Information Types
Single indication [1 Bit]
Single indication [1 Bit] with time tag
Measured value [12 bit]
Counter value [16 bit]
PCM, half-duplex, SDLC frame format/synchronisation Baud rates up to 2400
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
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
Available Protocol Stacks
HITACHI HC4300, Master
HITACHI HC4300, Slave
Universal protocol converter for small and distributed applications