hays.rb

require 'rmodbus'

module ModBus
  class Client
    def set_keepalive keepalive: true, keepidle: 50, keepintvl: 10, keepcnt: 5
      @io.setsockopt Socket::SOL_SOCKET, Socket::SO_KEEPALIVE,  keepalive
      @io.setsockopt Socket::SOL_TCP,    Socket::TCP_KEEPIDLE,  keepidle
      @io.setsockopt Socket::SOL_TCP,    Socket::TCP_KEEPINTVL, keepintvl
      @io.setsockopt Socket::SOL_TCP,    Socket::TCP_KEEPCNT,   keepcnt
    rescue
      warn 'TCP keepalive parameters not set. Continuing.'
    end
  end
end