Serial protocol master-master?

Hello,

I have started a project of home automation with CANBus.

On the CANBus, there are nodes which are arduino's cards. Each node has its own configuration and is standalone. Each node can transmit informations for the other nodes and each node knows what to do when it receives informations from others nodes.

But in this network, ther is one node which is connected to the PC. This specific node, the hub (router), can send message to the PC and can receive message from the PC. Actually, this node sends messages arriving from the CANBus to the PC and sends to the PC a message which indicate it can receive. it work's, but there is a lot of messages indicating it can receive.

So i search a protocol which can initiate dialog from the arduino when CANBus messages's arrive and can initiate from the PC when there is messages from the IHM for the CANBus network.

The PC is the master but the arduino is also the master. Someone knows about this kind of protocol?

Thanks

Normal serial (RS232) comms? Both ends can be listening for data independently.