Patent ID: 8356968

Claim:
A method for transferring a substrate carrier comprising: providing a load port associated with a process equipment tool; providing a controller associated with material handling equipment; providing a load port sensor adapted to detect a state of the load port and to indicate if the load port is empty, wherein said load port sensor detects an empty load port and indicates that the load port is empty independent of whether the process equipment tool is empty or contains a substrate; providing a communication link between the load port and the controller associated with the material handling equipment, wherein the communication link provides the material handling equipment with changes in the load port sensor state; performing a handshake directly between the load port and material handling equipment by transferring isolated input/output (I/O) signals, via the communication link, between the load port and material handling equipment; transferring a substrate carrier between the material handling equipment and the load port based on the handshake, wherein the handshake comprises an exchange of communication signals before and during the transfer of the substrate carrier; and exchanging communication signals after transfer of the substrate carrier via the handshake.