Class: Modbus::Transaction::Server

Inherits:
Base
  • Object
show all
Defined in:
lib/modbus/transaction/server.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from Modbus::Transaction::Base

Class Method Details

.recv_adu(buffer, conn) ⇒ true, false

Try to decode a response ADU from some recevied bytes and handle the ADU if decoding was successful.

Parameters:

Returns:

  • (true, false) —

    True, if there where enough bytes in the buffer and decoding was successful.



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# File 'lib/modbus/transaction/server.rb', line 17

def self.recv_adu(buffer, conn)
  adu = Modbus::TCPADU.new

  if adu.decode :request, buffer, conn
    transaction = self.new conn
    transaction.handle_request adu
    return true
  else
    return false
  end
end

Instance Method Details

#handle_read_holding_registers ⇒ Object 



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# File 'lib/modbus/transaction/server.rb', line 68

def handle_read_holding_registers
  read_registers 40001, PDU::ReadHoldingRegistersResponse
end

#handle_read_input_registers ⇒ Object 



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# File 'lib/modbus/transaction/server.rb', line 63

def handle_read_input_registers
  read_registers 30001, PDU::ReadInputRegistersResponse
end

#handle_request(adu) ⇒ Object

Handles a recevied ADU and calls the relevant callback. The corresponding request ADU is matched and cleaned up.

Parameters:

  • adu (Modbus::ADU) —

    The ADU to handle.



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# File 'lib/modbus/transaction/server.rb', line 48

def handle_request(adu)
  @request_adu = adu

  transaction = TRANSACTIONS.find { |t| adu.pdu.is_a? t[:request] }
  fail IllegalFunction,     "Unknown PDU #{adu.pdu.inspect}" unless transaction
  fail ServerDeviceFailure, "Unexpected last sent PDU: #{@request_adu.pdu.inspect}" unless @request_adu.pdu.is_a? transaction[:request]

  pdu = send transaction[:handler]
  send_pdu pdu

rescue ModbusError => error
  send_pdu PDU::Exception.create(adu.pdu.func_code, error)
end

#handle_write_multiple_registers ⇒ Object 



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# File 'lib/modbus/transaction/server.rb', line 81

def handle_write_multiple_registers
  reg_count      = @conn.write_registers 40001 + @request_adu.pdu.start_addr, @request_adu.pdu.reg_values
  pdu            = PDU::WriteMultipleRegistersResponse.new
  pdu.start_addr = @request_adu.pdu.start_addr
  pdu.reg_count  = reg_count
  pdu
end

#read_registers(offset, response_class) ⇒ Object 



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# File 'lib/modbus/transaction/server.rb', line 73

def read_registers(offset, response_class)
  reg_values     = @conn.read_registers offset + @request_adu.pdu.start_addr, @request_adu.pdu.reg_count
  pdu            = response_class.new
  pdu.reg_values = reg_values
  pdu
end

#send_pdu(pdu) ⇒ Modbus::TCPADU

Constructs a ADU using a PDU and send it asynchronusly to the server. The created ADU is stored internally and is matched to the response when the response is available.

Parameters:

Returns:



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# File 'lib/modbus/transaction/server.rb', line 36

def send_pdu(pdu)
  @response_adu = TCPADU.new pdu, @request_adu.transaction_ident
  @conn.send_data @response_adu.encode
  self
end