Class: ROPC::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/ropc/client.rb

Instance Method Summary collapse

Constructor Details

#initialize(tags: [], server: nil, node: nil, logger: Logger.new(STDOUT), level: "WARN") ⇒ Client

Returns a new instance of Client.



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# File 'lib/ropc/client.rb', line 20

def initialize(tags: [], server: nil, node: nil, logger: Logger.new(STDOUT), level: "WARN")
  @tags = tags
  
  @server = server
  @server ||= ENV["ROPC_SERVER"]
  fail "Environment variable ROPC_SERVER not set or not server given." if @server.nil?
  
  @node = node
  @node ||= ENV["ROPC_NODE"]
  fail "Environment variable ROPC_NODE not set or not node given." if @node.nil?
  
  @logger = logger
  @logger.level = level   
  
  establish_connection
end

Instance Method Details

#add(tag) ⇒ Object 



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# File 'lib/ropc/client.rb', line 84

def add(tag)
  begin
  	@items[tag] = @opc_items.AddItem(tag, 1)	
  rescue
    @logger.warn("Failed to add this tag: #{tag}")
  end
end

#cleanup ⇒ Object 



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# File 'lib/ropc/client.rb', line 127

def cleanup
  @opc_groups.RemoveAll if @opc_groups
  @opc_automation.Disconnect if @opc_automation
end

#establish_connection ⇒ Object 



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# File 'lib/ropc/client.rb', line 37

def establish_connection
  begin
    @opc_automation = WIN32OLE.new 'OPC.Automation.1'
    @logger.info("OPC.Automation.1 created.")
  rescue => err
    @logger.fatal("Cannot create win32ole OPC Automation object")
    @logger.fatal(err)
    exit
  end
  
  begin
    @opc_automation.Connect(@server,@node)
    @logger.info("Connected to OPC Server.")        
    @logger.info("OPC Server StartTime: #{@opc_automation.invoke("StartTime")}") # returns Time Class
    @logger.info("OPC Server CurrentTime: #{@opc_automation.invoke("CurrentTime")}") # returns Time Class        
  rescue => err
    @logger.fatal("Cannot connect to OPC #{@server} on #{@node}")
    @logger.fatal(err)
    exit
  end
  
  begin
    @opc_group = @opc_automation.OPCGroups.add "OPCGroup"
    @opc_items = @opc_group.OPCItems
    #opc_group.UpdateRate = 1000
    @logger.info("Group UpdateRate: #{@opc_group.UpdateRate}")
    @logger.info("OPC Group IsSubscribed: #{@opc_group.IsSubscribed}")
    @logger.info("OPC Group IsActive: #{@opc_group.IsActive}")
  rescue => err
    @logger.fatal("Could not add OPCGroup")
    @logger.fatal(err)
    exit
  end

  @items = {}
  
  if @tags.respond_to?("each")
    @tags.each {|tag| self.add tag }
  else
    self.add @tags
  end

  @logger.info("Number of OPCGroup in OPCGroups: #{@opc_automation.OPCGroups.Count}")      
  @logger.info("Number of OPCItem in OPCitems: #{@opc_items.Count}")
  
end

#extract_value(str) ⇒ Object 



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# File 'lib/ropc/client.rb', line 132

def extract_value str      
  begin
    if str.kind_of?(FalseClass)             
        return 0.0          
    elsif str.kind_of?(TrueClass)             
        return 1.0                  
    elsif Float(str)          
      return str            
    elsif Int(str)          
      return str                    
    end
  rescue 
    @logger.warn("failed to extract value: #{str}; returning 0.0")
    return 0.0
  end      
end

#read ⇒ Object 



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# File 'lib/ropc/client.rb', line 115

def read
    read_all
end

#read_all ⇒ Object 



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# File 'lib/ropc/client.rb', line 119

def read_all
  tags = []
  @items.keys.each do |tag|	
    tags << read_tag(tag)
  end
  return tags
end

#read_tag(tag) ⇒ Object 



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# File 'lib/ropc/client.rb', line 96

def read_tag(tag)
    if @items.has_key?(tag)
            opcitem = @items[tag]
            begin
              opcitem.read OPCDataSource::OPCCache # 1: reading from cache, 2: reading from device          
            rescue
              @logger.warn("Failed to read opc tag: #{tag}")
              cleanup
              establish_connection
              return tags
            end
            ts = opcitem.TimeStamp + opcitem.TimeStamp.gmtoff
            @logger.info("Read #{opcitem.ItemID} Value: #{extract_value(opcitem.Value)}, Quality: #{OPCQuality::OPCQuality[opcitem.Quality]}, Time: #{ts}")
            return {tag: opcitem.ItemID, value: extract_value(opcitem.Value), quality: OPCQuality::OPCQuality[opcitem.Quality], timestamp: ts}          
    else
            return {}
    end
end

#remove(tag) ⇒ Object 



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# File 'lib/ropc/client.rb', line 92

def remove(tag)
  @items.delete(tag) if @items.has_key?(tag)
end