Class: ModBus::TCPServer

Inherits:
GServer
  • Object
show all
Includes:
Debug, Server
Defined in:
lib/rmodbus/tcp_server.rb

Overview

TCP server implementation

Examples:

srv = TCPServer.new(10002, 1)
srv.coils = [1,0,1,1]
srv.discrete_inputs = [1,1,0,0]
srv.holding_registers = [1,2,3,4]
srv.input_registers = [1,2,3,4]
srv.debug = true
srv.start

Constant Summary

Constants included from Server

Server::Funcs

Instance Attribute Summary

Attributes included from Server

#coils, #discrete_inputs, #holding_registers, #input_registers, #uid

Attributes included from Debug

#debug, #raise_exception_on_mismatch, #read_retries, #read_retry_timeout

Instance Method Summary collapse

Constructor Details

#initialize(port = 502, uid = 1, opts = {}) ⇒ TCPServer

Init server

Parameters:

  • port (Integer) (defaults to: 502) —

    listen port

  • uid (Integer) (defaults to: 1) —

    slave device

  • opts (Hash) (defaults to: {}) —

    options of server

Options Hash (opts):

  • :host (String) —

    host of server default ‘127.0.0.1’

  • :max_connection (Float, Integer) —

    max of TCP connection with server default 4



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# File 'lib/rmodbus/tcp_server.rb', line 27

def initialize(port = 502, uid = 1, opts = {})
	@uid = uid

    warn "[WARNING] Please, use UID = 255. It will be fixed in the next release." if @uid != 0xff

    opts[:host] = DEFAULT_HOST unless opts[:host]
    opts[:max_connection] = 4 unless opts[:max_connection]
	super(port, host = opts[:host], maxConnection = opts[:max_connection])
end

Instance Method Details

#serve(io) ⇒ Object

Serve requests

Parameters:

  • io (TCPSocket) —

    socket



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# File 'lib/rmodbus/tcp_server.rb', line 39

def serve(io)
  while not stopped?
    header = io.read(7)
    tx_id = header[0,2]
    proto_id = header[2,2]
    len = header[4,2].unpack('n')[0]
    unit_id = header.getbyte(6)
    if proto_id == "\x00\x00"
      req = io.read(len - 1)
      if unit_id == @uid || unit_id == 0
        log "Server RX (#{req.size} bytes): #{logging_bytes(req)}"

        pdu = exec_req(req, @coils, @discrete_inputs, @holding_registers, @input_registers)

        resp = tx_id + "\0\0" + (pdu.size + 1).to_word + @uid.chr + pdu
        log "Server TX (#{resp.size} bytes): #{logging_bytes(resp)}"
        io.write resp
      else
        log "Ignored server RX (invalid unit ID #{unit_id}, #{req.size} bytes): #{logging_bytes(req)}"
      end
    end
  end
end