Class: Lxi::Device

Inherits:
Object
  • Object
show all
Includes:
FFI
Defined in:
lib/lxi/device.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(address, protocol = :vxi11) {|_self| ... } ⇒ Device

Returns a new instance of Device.

Yields:

  • (_self)

Yield Parameters:

  • _self (Lxi::Device) —

    the object that the method was called on



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# File 'lib/lxi/device.rb', line 9

def initialize(address, protocol = :vxi11)
  @address = address
  @port = 0
  @name = nil
  @timeout = 1000
  @protocol = protocol
  @id = -1

  connect

  yield(self) if block_given?
end

Instance Attribute Details

#address ⇒ Object

Returns the value of attribute address.



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# File 'lib/lxi/device.rb', line 7

def address
  @address
end

#id ⇒ Object

Returns the value of attribute id.



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# File 'lib/lxi/device.rb', line 7

def id
  @id
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/lxi/device.rb', line 7

def name
  @name
end

#port ⇒ Object

Returns the value of attribute port.



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# File 'lib/lxi/device.rb', line 7

def port
  @port
end

#protocol ⇒ Object

Returns the value of attribute protocol.



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# File 'lib/lxi/device.rb', line 7

def protocol
  @protocol
end

#timeout ⇒ Object

Returns the value of attribute timeout.



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# File 'lib/lxi/device.rb', line 7

def timeout
  @timeout
end

Instance Method Details

#connect ⇒ Object Also known as: open

Raises:



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# File 'lib/lxi/device.rb', line 22

def connect
  Lxi.init_session

  @id = Lxi.connect(@address, @port, @name, @timeout, @protocol)
  raise(Error, 'LXI Connection Error') if @id == LXI_ERROR

  true
end

#disconnect ⇒ Object Also known as: close 



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# File 'lib/lxi/device.rb', line 32

def disconnect
  Lxi.disconnect(@id)
end

#query(message, bytes = 512, resp_delay: 0.02) ⇒ Object 



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# File 'lib/lxi/device.rb', line 55

def query(message, bytes = 512, resp_delay: 0.02)
  write(message)
  sleep :resp_delay
  read(bytes)
end

#read(length) ⇒ Object Also known as: gets

Raises:



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# File 'lib/lxi/device.rb', line 46

def read(length)
  message = FFI::MemoryPointer.new(:char, length)
  bytes_received = Lxi.receive(@id, message, length, @timeout)
  raise(Error, 'LXI communications error') unless bytes_received.positive?

  message.read_string
end

#write(message) ⇒ Object Also known as: scpi, send

Raises:



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# File 'lib/lxi/device.rb', line 37

def write(message)
  bytes_sent = Lxi.__send(@id, message, message.length, @timeout)
  raise(Error, 'LXI communications error') unless bytes_sent.positive?

  bytes_sent
end