Machine host computer interface

A factory-wide networked production monitoring is part of an overall production planning and provides all information on a database, which is necessary for a comprehensive analysis of the entire production. Thus, the management is able to plan production in an optimal way and at the same time to react accordingly to production failures and disturbances. Figure 5.22 shows the structure of such a system. This is based on a stand-alone web server. Every authorized user can access it using a standard web browser. The process information can be collected without expensive and time-consuming connections via machine host computer interfaces. 

These never ending advanced controls allow interfacing many machines to a common host computer that allows plant-wide monitoring of the overall production status. The many software developments are rapidly changing the character of the molding machine.3... 

Recently all of the temperature, pressure, and time controls have been replaced with a single microprocessor-based controller. A number of these are available and they allow for complex pressure and temperature curves to be programmed with multiple soaking levels and variables that can be chosen. Built-in memories recall previous programs and cassettes can store them on the shelf. Interfaces can connect with a central host computer for data collection or actual machine setup and supervision. The result is more flexible, more exacting, and easier to control modern molding equipment (Chapter 3). 

Once the need for a network has been determined, the locations of terminals, servers, and information storage equipment must be established. Local area networks (LANs) and the worldwide web (WWW, or Internet) can link access points located in adjacent rooms or halfway around the world. However, it is critical that the network uses consistent computer and data transmittal protocols in order to provide uninterrupted, information handling in an efficient manner. For example, serial communication via an RS-232 port is relatively common, but too slow for most machine applications. Ethernet communication via transmission control protocol/Internet protocol (TCP/IP) is a preferred method because most equipment suppliers offer this network option. The TCP/IP method allows computers to share resources, no matter whether the operating system is for an Apple , a version of the Microsoft operating system for PCs, or the UNIX operating system. Also, the Semiconductor Equipment Communication Standard (SECS)/Generic Equipment Model (GEM) is widely used as the interface between the host computer and assembly machines. 

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