Original article posted in SBW!RE. Link to original article here.
According to John Rattray of Memex Automation, “Customers have asked how a Memex Ax9150 Universal Machine Interface (UMI) compares to a typical Programmable Logic Controllers (PLC). In answering, we are faced with the same dilemma as the apple to tennis ball. Both the UMI and PLC have digital inputs and outputs, but that is where the comparison ends. A PLC is only a hardware component, whereas the Memex Ax9150 UMI is a full system of hardware, firmware, software applications and configuration tools designed to connect to any machine. The Memex Ax9150 UMI is part of a comprehensive OEE+DNC production monitoring and control system that ties the Shop Floor to the Top Floor.”
A PLC has no operator interface and cannot be used with just any machine. In contrast, the UMI is specifically designed to connect with ALL machines. Although the UMI collects most data automatically so that operator input is not mandatory, such input is often used to further increase the system’s functionality, an option not easily accomplished without expensive custom services for a PLC.
To re-create the Memex Productivity system with just a PLC collecting digital I/O points is virtually impossible according to Rattray. “Manufacturers would have to add an HMI plus advanced configuration and custom code development services. Moreover, the cost of developing a PLC-based system for use as an OEE shop floor interface historically has cost $15,000 – 20,000+ per machine and has required extensive, support services, and is most often a non starter for a company due to the overall cost of the project. Compare this reality with the $4,000 per machine cost (installed) of the UMI — it is now affordable.”