Patent ID: 6910086

Claim:
A controller device for controlling a plurality of target devices connected to a data bus for transferring data in a predetermined communication format, said controller device comprising: first command generating means for generating a first reserve command for permitting transmission of commands from the controller device sending the first reserve command to a first target device that accepts the first reserve command from the controller device, and for inhibiting communication between the first target device and all other of the target devices and all other controller devices; second command generating means for generating a second reserve command for permitting transmission of commands from the controller device to the first target device, and for permitting transmission of at least one designated command to said first target device from other controller devices, and for inhibiting communication of other than the at least one designated command to said first target device from the other controller devices; and transmitting means for selectively transmitting to said target devices and other controller devices said first reserve command generated by said first command generating means and for selectively transmitting to said target devices said second reserve command generated by said second command generating means, wherein said predetermined communication format complies with IEEE 1394 criteria.