gistfile1.txt

require 'direct_connect'
require 'builder'

task :ping do
  xml = Builder::XmlMarkup.new(indent: 2)
  xml.instruct!
  xml.OTA_PingRQ {
    xml.EchoData 'Hello World'
  }

  puts xml
  DirectConnect.request(:ping, xml)
end

gistfile2.txt

rake aborted!
TypeError: can't convert Builder::XmlMarkup to Array (Builder::XmlMarkup#to_ary gives String)