Read BACnet ObjectValues

[josher]

Hello everyone!
I am beginning with BACnet4j project. I think it is a great project, so i am very glad with it.
I am trying to read BACnet object values from my computer with a Java project. My code is:

public class BACnetNetwork {
	static LocalDevice lDevice;
	static ResourceBundle resource = ResourceBundle.getBundle("resources/bacnet4j");
	
	public BACnetNetwork(){}
	
	public static void main(String args[]){
		initializeDevice();
	}
	
	public static void initializeDevice(){
		try{
			System.out.println("Inicializando...");
			lDevice = new LocalDevice(17800, resource.getString("localDeviceIP"));
			lDevice.getEventHandler().addListener(new Listener());

			lDevice.initialize();
			//System.out.println("Remote Devices..."+lDevice.get);
			
			@SuppressWarnings("unused")
			ReadPropertyRequest read = new ReadPropertyRequest(new ObjectIdentifier(ObjectType.analogInput, 243), PropertyIdentifier.presentValue);
	        getObjectList(lDevice, resource.getString("deviceIP"), Integer.valueOf(resource.getString("port")), 17800);  
		}catch(Exception e){
			System.out.println("Error al inicializar "+e.getMessage());
		}finally{
			closeDevice();
		}
	}
	
	public static void closeDevice(){
		try{
			lDevice.terminate();
		}catch(Exception e){
			System.out.println(e.getMessage());
		}
	}
	
	private static void getObjectList(LocalDevice localDevice, String ip, int port, int deviceId) throws Exception {  
        InetSocketAddress addr = new InetSocketAddress(InetAddress.getByName(ip), port);
        System.out.println(addr.toString());
       
        ReadPropertyRequest read = new ReadPropertyRequest(new ObjectIdentifier(ObjectType.device, deviceId), PropertyIdentifier.objectList);
        ReadPropertyAck ack = (ReadPropertyAck) localDevice.send(addr, null, 1476, Segmentation.segmentedBoth, read);
        System.out.println("IP: " + ip);

        @SuppressWarnings("unchecked")
		SequenceOf<ObjectIdentifier> oids = (SequenceOf<ObjectIdentifier>) ack.getValue();  
        for (ObjectIdentifier oid : oids) {
            System.out.println("    " + oid.getObjectType());  
        }  
        
		PropertyIdentifier pids = (PropertyIdentifier) ack.getValue();  
        System.out.println("    " + pids);    
    } 
	
	static class Listener extends DefaultDeviceEventListener {  
        @Override  
        public void iAmReceived(RemoteDevice d) {  
            System.out.println("I am received" + d);  
        }  
    } 

However, when I run, the output shows:

P: 192.168.107.247
    Device 17800
    Analog Input 0
    Multi-state Input 0
    Analog Input 1
    Trend Log 1
    Trend Log 2
    Trend Log 3
    File 0

I have been studying a BACnet frame from Wireshark, but I do not see any value.

How could I read values from a device?
Thank you very much!!
Regards!

Attachment: download link

[mlohbihler]

BACnet4J does not store present values for objects. You need to request them using ReadProperty or ReadPropertyMultiple requests, asking objects for their present value property.

[josher]

@mlohbihler said:

BACnet4J does not store present values for objects. You need to request them using ReadProperty or ReadPropertyMultiple requests, asking objects for their present value property.

But in my code I am already using "ReadPropertyRequest". Another option is "ReadPropertyMultipleRequest"
Thanks!

[mlohbihler]

The only property that you are reading is objectList.

[josher]

@mlohbihler said:

The only property that you are reading is objectList.

Ok!! Thank you very much!! I solve the problem. So, do I need send a ReadPropertyRequest and a ReadPropertyAck for each property? I have tried with PropertyIdentifier.all, however it throws an Exception. If I send a request for each property I can see that property, but I think it could be a lot of load in BAcnet network...
Regards!

[mlohbihler]

Using the "all" identifier will often result in an exception because the content is too much to put into a single response. BACnet4J will try to compensate in come cases, but it doesn't always work out.

You can ask for multiple properties with a ReadPropertyMultiple request, as long as your equipment supports it.

[djrosu]

Hello, I am trying to figure out how to use bacnet4j and this thread is helpful however I am still stuck on the various IP addresses and ports used? Can you explain the difference between resource.getString("localDeviceIP"), resource.getString("deviceIP") and resource.getString("port")? Thanks in advance.