... by PLC.person and machine have a conversation with computer.Fault dignosis and long-distance contrlollingis eas QT9- ... controlled by PLC.person and machine have a conversation with computer.Fault dignosis and long-distance contrlollingis easy to ... blocks, solid/hollow/cellular masonry products, paving stones with or without face mix, garden and landscaping products, slabs, edgers, kerbstones ...