Look more closely at how a PAC (Programmable Automation Controller) is applied to a modern industrial application using the factory application. The PAC is operating in multiple domains to manage and monitor a production line, a chemical process, a test bench and shipping activities. The PAC must simultaneously manage analog values such as temperatures and pressures, switches, digital on/off states for valves, and indicators; and serial data from inventory tracking and test equipment. At the same time, the PAC is exchanging data with an OLE for Process Control (OPC) server, a Structured Query Language (SQL) database and an operator interface. Handling simultaneously these tasks without need for additional processors, middleware, or gateway is a hallmark of a PAC.
The PAC, office workstation and operator, testing equipment, production line and process actuators and sensors, and barcode reader are connected to a standard 10/100 Mbps Ethernet network installed throughout the facility. In some examples, devices without built in Ethernet connectivity such as temperature sensors are connected to I/O modules on an intermediate Ethernet enabled I/O unit, which is turn communicates with the PAC.
The PAC communicates with remote racks of I/O modules to read or write analog, digital and serial signals using this Ethernet network. The network also links the PAC with as OPC server, a SQL database, and an operator interface. A wireless segment is part of the network, so the PAC can also communicate with the mobile assets like the temporary operator workstations and forklift.
The PAC can control, exchange data and monitor with this wide variety of systems and devices because it uses the same standard network technologies and protocol that they use. This example includes wireless and wired Ethernet networks, IP (Internet protocol), network transport, SQL and OPC. In other control situation, common application level protocols such as Modbus, Simple Network management Protocol (SNMP), Potin to point Protocol (PPP) over a modem could be required. The PAC has the ability to meet these requirements of diverse communication.