How communicate to a remote device ?

[Valter Henrique]

Hi,
I made a local device communicate with my application.
But how do I make to communicate to a remote device ?

Is possible to do this using ip or dns ? (because the ip changes sometimes).

[mlohbihler]

Hi Valter,

What do you mean by remote? I suspect you mean a device with which you cannot exchange a WhoIs/IAm, but please confirm.

If this is the case, you will need to manually instantiate a RemoteDevice by explicitly providing the IP, port, and instance id. Then, you will be able to send messages to it.

Regarding using a domain name, BACnet only deals with IP addresses, so you will need to handle domain name resolution yourself.

[Valter Henrique]

@mlohbihler said:

Hi Valter,

What do you mean by remote? I suspect you mean a device with which you cannot exchange a WhoIs/IAm, but please confirm.

If this is the case, you will need to manually instantiate a RemoteDevice by explicitly providing the IP, port, and instance id. Then, you will be able to send messages to it.

Regarding using a domain name, BACnet only deals with IP addresses, so you will need to handle domain name resolution yourself.

I mean, a device that is not in my network.
There's some example in the test folder that could use for that ?

[mlohbihler]

I don't think so, but it's not hard. The only trick is that you need to know the instance id of the device.

RemoteDevice rd = new RemoteDevice(...);
localDevice.addRemoteDevice(rd); // This may not actually be necessary
localDevice.send(rd, myRequest);

Where "myRequest" is, say, a read property with pid of objectList. If your setting are correct, you should get the object list of the remote device.

[Valter Henrique]

@mlohbihler said:

I don't think so, but it's not hard. The only trick is that you need to know the instance id of the device.

RemoteDevice rd = new RemoteDevice(...);
localDevice.addRemoteDevice(rd); // This may not actually be necessary
localDevice.send(rd, myRequest);

Where "myRequest" is, say, a read property with pid of objectList. If your setting are correct, you should get the object list of the remote device.

I found the id of my device, it's 101, but I have some doubts about it :

    public static void main(String[] args) throws Exception {
        // How to initialize the LocalDevice ?
        LocalDevice ld = new LocalDevice (???);

        // let's say my ip is : 1.2.3.4, is this correct ?
    	RemoteDevice rd = new RemoteDevice(101, new Address(new byte[] { (byte) 1, (byte) 2, 3, (byte) 4 }, 47808), null);
        ld.addRemoteDevice(rd);

        // now I have the remote device, in the localDevice, now I should be able to use the method 'getObjectList()' ?
       
        // how to use this 'myRequest' (I don't understand what you said about it ) ?
        localDevice.send(rd, myRequest);
        ...
}

[mlohbihler]

Ok, now i'm wondering what you meant when you said:

I made a local device communicate with my application.

Anyway, a request is a key component of BACnet. It's how all communication is done with BACnet peers (aka RemoteDevices). Have a look at LocalDevice.findRemoteDevice (and ignore the code that i provided previously). You should be able to see what is going on.

[R-GiGgS84]

@Valter Henrique said:

@mlohbihler said:
I don't think so, but it's not hard. The only trick is that you need to know the instance id of the device.

RemoteDevice rd = new RemoteDevice(...);
localDevice.addRemoteDevice(rd); // This may not actually be necessary
localDevice.send(rd, myRequest);

Where "myRequest" is, say, a read property with pid of objectList. If your setting are correct, you should get the object list of the remote device.

I found the id of my device, it's 101, but I have some doubts about it :

   public static void main(String[] args) throws Exception {
       // How to initialize the LocalDevice ?
       LocalDevice ld = new LocalDevice (???);

       // let's say my ip is : 1.2.3.4, is this correct ?
   	RemoteDevice rd = new RemoteDevice(101, new Address(new byte[] { (byte) 1, (byte) 2, 3, (byte) 4 }, 47808), null);
       ld.addRemoteDevice(rd);

       // now I have the remote device, in the localDevice, now I should be able to use the method 'getObjectList()' ?
      
       // how to use this 'myRequest' (I don't understand what you said about it ) ?
       localDevice.send(rd, myRequest);
       ...
}

Hi mlohbihler ,

Can u give an example of how u instantiate myRequest?

Regards,
WenJun

[mlohbihler]

Anyway, a request is a key component of BACnet. It's how all communication is done with BACnet peers (aka RemoteDevices). Have a look at LocalDevice.findRemoteDevice (and ignore the code that i provided previously). You should be able to see what is going on.

[Valter Henrique]

In the end I created a server (which runs in the computer that's locally placed in my network) and then communicate via socket.

Until I found out how implement a RemoteDevice that you said, thanks mlohbihler.