Hello!

I would like to ask about Report/QueryIndentification and Report/QueryServices messages. Problem is that if I use first two messages, first quering id and then in respons reporting id, application work fine, but ojNodeManager prints ERROR message in terminal. Message says "Received ReportID with undefined queryType", from CommunicatorComponent::processReportIdentification().

In addition, if I use latter services messages, application works fine, but if I command 'T', my component do not have any services left. If comment this message out, my components services are back. This happens in both, node and subsystem level.

My application suppose to use these two messages mention above for discovery services. Identification message work fine and without error messages in node level but not in subsystem level. Why?

I noticed also that in node/subsystem level these messages are sent automatically between ojNodemanager and components, am I right?
Thanks in advance and nice work on renewing site.

-JV

JV,

I'm having some trouble understanding your problem. The ojNodeManager automatically handles discovery at the component, node and subsystem levels. Are you trying to query the node manager or communicator for information? Please describe what it is that you are trying to do and I think we can find a solution for you.

Tom

JV,

Thanks for the compliment on the new site. Tom and I worked hard to try to bring a better experience for everyone and it is nice to see people using it.

Let's take a look at your problem from a higher level for a second. If you could answer a few general questions, it will help me to understand your desired outcome.

1. You state you want to use the Identification and Services messages for discovery in your application's component. What are you trying to discover? If you take a look at the SystemTree class in the NodeManager code and some of the discovery message parsing code in the NodeManagerComponent and CommunicatorComponent classes, you will see that discovery of the entire possible system architecture is a complex task. To ease this task, OpenJAUS tries to handle the construction and maintenance of the SystemTree at the NodeManager level and provide access to this data through the ojCmptLookupAddress() function. However, support for looking up a service address was left out of the ojCmpt interface (it is part of the underlying libNodeManager interface). If that is something the community needs it can easily be added.

2. You are correct that the ojNM sends the QueryIdentification and QueryServices messages to components automatically. This is based on receiving a heartbeat from a component. I've attached an image of the NodeManager component's behavior upon receipt of a Heartbeat message. This shows how the NM behaves when a ReportHeartbeatPulse message is received from any JAUS entity. This chart was made as part of the NM design we did in late 2007 when we built the latest node manager.


So hopefully that gives you a little background about what is going on in the NodeManager. If you can provide us with some more insight into your thought process and what you want to accomplish, hopefully we can find the solution that works for you.

~Danny

Hi K & T!

Thank you for your answers. Sorry the unclear question, but basically I just try to send report message from my component when it gets query. For example, I have developed similar function like in ojVehicleSim components have(processMessage()) and when I got QueryIdentification, my primitive driver tried to send ReportIdentification to component that was asking for it. But if ojNodeManager does it automatically in node/subsystem/component level, I do not have to worry about it?

-JV

JV,

Yes, that's correct. In almost all cases you shouldn't have to worry about identifications unless your component needs to do something special with them. If you still need some specific functionality that you're having trouble with please let us know and we'll help you figure out how to do it!

Tom