The next publication of the NFPA-79 Electrical Standard for Industrial Machinery is expected to allow the use of PCs for machine control in addition to PLC machine control. In the future, machinery will have an Ethernet connection to upload production data and machine state into high-level business systems, Ferrante stated. “Packaging machines may exchange machine state information by communication rather than hardwire. In addition you will be able to purchase code daters, digital servo drives, etc. which will be set up by the machine PC using ‘plug and play’ interfaces.”
Many packaging machines operating in Europe are now PC controlled rather than PLC controlled. The manufacturers of safety devices and systems are responding with dedicated systems that will allow a machine to have safety systems that talk with a PC but operate independently so the equipment is not dependent on MS Windows for safety.
Version 1.1 of the guidelines is available at www.packml.org. The Pack ML (machine language) group has also developed a simulator to demonstrate how common machine state information can be used to identify line operations and bottlenecks (available at www.packml.org/simulation).
A PMMI conference will address this topic on July 15-17, 2002 in Rosemont, IL. For information, visit www.pmmi.org/safety.