A key PACs defining of characteristic is that the same hardware can be used in multiple domains, including logic, drives, motion, and process control, it follows that the software must be capable of programming all control and monitoring tasks that must be done in multiple domains.
That means that the PAC software must handle discrete control, motion control, process control, remote monitoring, and data acquisition. And the software must let the developer incorporate and mix these as needed into control programs, so the programs can flow as the requirements of the application dictate.
For instance the company is a microbrewery. Here are just some of the requirements to produce your end product:
• Water is piped in from a spring a couple of miles away, so you need to monitor the flow and pressure of that water as well as security at the spring, remote monitoring using digital sand analog devices.
• You measure water quality as it enters your facility, track this data overtime, and store it in your company database, data base acquisition, and data base connectivity.
• You make more than one microbrew, so recipes, temperature and processing must vary (PID loop control, batch process control, and distributed control.
• Operator interfaces the process mimic, providing secure interactive controls for technicians and operators.
• Quality control is essential to your reputation, so you test all products at some stages. Quality must meet as required by government health authorities, monitoring, more database connectivity and data acquisition.
• The bottling line requires discrete control in another building. They identified with Radio Frequency Identification tags.