Brian Dorey build this DIY Pick and Place USB controller board:
Every time the Mach3 software sent a command there would be a short delay of around 100-200 milliseconds and with each component placed using around seven commands it was adding a few seconds to the placement time for each part. On some of our boards which have over 100 components this was adding a sizable delay to each boards build time.
To resolve this and also to reduce the number of separate boards in the machine we decided to build a single controller board which would have its own microprocessor and switching systems.