[DAType]
public class DeviceA
{
 
   [DASubPath]
   public string DeviceIdCode {get;set;}
 
   [DANode()] 
   [DAItem()]
   public int SomeStatus {get;set;}
}
 
[DAType]
public class DeviceB
{
   [DASubPath]
   public string DeviceIdCode {get;set;}
 
   [DANode()] 
   [DAItem()]
   public int SomeStatus {get;set;}
}
 
[DAType]
public class ProductionLine
{
       [DANode()] 
       [DAItem()]
	public int OtherSomeStatuses {get;set;}
 
	[DANode()] //<--- ??????
	public List<DeviceA> DevicesA {get;set;}
 
	[DANode()] //<--- ??????
	public List<DeviceB> DevicesB {get;set;}
}

//1. Loading devices from configuration
 
  ProductionLine pl = LoadFromConfiguration();
 
 
//now "pl" contains e.g. 10 devices A and 15 devices B.
 
 
//2. Now I would like mapp this object (with out loop)
 
  var mapper = new DAClientMapper();   
 
  mapper.Map(pl, new DAMappingContext                                            
   {                                                                               
     ServerDescriptor = sd,   // local OPC server                                                      
			NodeDescriptor = new DANodeDescriptor 
                       { BrowsePath = "/TestChannel/MainGroup/ProductionLine/"}, 
			GroupParameters = 1000,  
		});               				
     }

public class Line
{
    public List<Device> Devices {get;set;}
}

[DAType]
public class Device
{
 
   public string DeviceCode {get;set;}
 
   [DANode()] 
   [DAItem()]
   public bool  IsRunning {get;set;}   
 
   [DANode()] 
   [DAItem()]
   public int Speed {get;set;}
 
 
   [DANode()] 
   [DAItem()]
   public int Position {get;set;}
}
 
 
 
public class LineDef
{
   public LineDef()
	{
	  Devices = new List<Device>();
	}
   public List<Device> Devices {get;set;}
}
 
 
void Main()
{
 
    var sd = "Kepware.KEPServerEX.V5";
    //initialization object
	var line = new LineDef();
    line.Devices.Add(new Device() { DeviceCode="dev1"});
	line.Devices.Add(new Device() { DeviceCode="dev2"});
	line.Devices.Add(new Device() { DeviceCode="dev3"});
	line.Devices.Add(new Device() { DeviceCode="dev4"});
	line.Devices.Add(new Device() { DeviceCode="dev5"});
 
     //preparing mapping
     var mapper = new DAClientMapper();   
 
	 foreach(var dev in line.Devices)
	 {
		mapper.Map(dev, new DAMappingContext                                            
		{                                                                               
			ServerDescriptor = sd,   // local OPC server                                                      
			NodeDescriptor = new DANodeDescriptor { BrowsePath = "/TestChannel/MainGroup/Line1/" + dev.DeviceCode}, 
			GroupParameters = 1000,  
		});                                                                             
	 }
 
	mapper.Read();
 
	var i = 1;
	foreach(var dev in line.Devices)
	{
	   dev.IsRunning = true;
	   dev.Position = 10 * i;
	   dev.Speed = 30;
	   i++;
	}
 
	mapper.Write();
}