A clustered substrate processing system comprising a plurality of lithography elements, each lithography element arranged for independent exposure of substrates according to pattern data. Each lithography element comprises a plurality of lithography subsystems, a control network arranged for communication of control information between the lithography subsystems and at least one element control unit, the element control unit arranged to transmit commands to the lithography subsystems and the lithography subsystems arranged to transmit responses to the element control unit, and a data network arranged for communication of data logging information from the lithography subsystems to at least one data network hub, the lithography subsystems arranged to transmit data logging information to the data network hub and the data hub arranged for receiving and storing the data logging information. The system further comprises a cluster front-end for interface to an operator or host system, the cluster front-end arranged for transmitting control information to the at least one machine control unit to control operation of the lithography subsystems for exposure of one or more wafers, and the front-end further arranged for receiving at least a portion of the data logging information received by the data network hub.