Problem with Read Property Request

[mlohbihler]

Ok, but can you post the stack trace? I assume the line numbers are different now.

[decora]

Yes, the line numbers are different.
This is the stack trace:

Exception in thread "main" java.lang.NullPointerException
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.send(IpMessageControl.java:226)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:480)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:470)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:463)
	at Prova_B4J.main(Prova_B4J.java:143)

[mlohbihler]

Your remote device has a segmentationSupported value of null. Normally you wouldn't instantiate your own RemoteDevice objects, BTW. An IAm (resulting from a WhoIs broadcast) is the typical means of instantiation. A "manual" way to get remote devices is to use the LocalDevice.findRemoteDevice method.

[decora]

I tried your solutions, but there are other problems.
If I use:

remoteDevice=localDevice.findRemoteDevice( new Address(new byte[] { (byte) 192, (byte) 168, (byte) 1, (byte) 112 },0xBAC0 ), null, 1);

eclipse return this exception:

Exception in thread "main" com.serotonin.bacnet4j.exception.BACnetException: java.lang.NullPointerException
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.sendImpl(IpMessageControl.java:377)
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.send(IpMessageControl.java:302)
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.send(IpMessageControl.java:248)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:480)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:470)
	at com.serotonin.bacnet4j.LocalDevice.findRemoteDevice(LocalDevice.java:1047)
	at Prova_B4J_2.main(Prova_B4J_2.java:57)
Caused by: java.lang.NullPointerException
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.sendImpl(IpMessageControl.java:374)
	... 6 more

If I use:

localDevice.sendBroadcast(0xBAC0,new WhoIsRequest(null,null));

eclipse return:

Exception in thread "main" com.serotonin.bacnet4j.exception.BACnetException: java.lang.NullPointerException
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.sendImpl(IpMessageControl.java:377)
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.sendBroadcast(IpMessageControl.java:359)
	at com.serotonin.bacnet4j.LocalDevice.sendBroadcast(LocalDevice.java:520)
	at Prova_B4J_2.main(Prova_B4J_2.java:59)
Caused by: java.lang.NullPointerException
	at com.serotonin.bacnet4j.npdu.ip.IpMessageControl.sendImpl(IpMessageControl.java:374)
	... 3 more

[mlohbihler]

Did you initialize the local device before sending those requests?

[decora]

Perfect!! Thnak you very, but very very very much for the help!

I have only another questions...If I send an I-am message from VTS to instantiate the remote device in my java program, I have no problem ... but if I send it from another java program (always based on bacnet4j), eclipse returns this exception when I send the ReadPropertyRequest:

Exception in thread "main" com.serotonin.bacnet4j.exception.ErrorAPDUException: ErrorAPDU(choice=5, errorClass=Object, errorCode=Unknown object)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:489)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:470)
	at com.serotonin.bacnet4j.LocalDevice.send(LocalDevice.java:463)
	at Prova_B4J_2.main(Prova_B4J_2.java:106)

[mlohbihler]

Your BACnet4J device does not have the object you are looking for. You need to create a BACnet object with the correct properties, and then add it to the local device.

[decora]

Thank you mlohbihler! You have been my salvation!

[mlohbihler]

Glad to help. Buy a license. :)

[decora]

:wink: