US Patent 7375035 Host and ancillary tool interface methodology for distributed processing

A host and ancillary tool interface methodology for distributed processing is described. The host tool manages a process, except for the generation of a product used in the process. To generate the product, the host tool provides an indication to an ancillary tool that the product is to be generated, and the ancillary tool generates the product after detection of the indication with no further intervention by the host tool. To provide the indication, the host tool preferably activates a control line whose voltage is monitored by the ancillary tool, or alternatively, sets one or more bits in a memory which is periodically checked by the ancillary tool.