As a multi-functional control platform, the PAC system can combine and match related technologies and products according to the needs of the system to achieve functional focus. Because the development is based on the same development platform, the PAC system ensures the functions of the control system. Modules are unified, not just a collection of completely unrelated components, providing a common development platform and a single database to meet the needs of multi-domain automation system design and integration, allowing users to be on the same platform according to system implementation requirements Run multiple applications with different functions, and allocate system resources among programs according to the design requirements of the control system, support the de facto industrial Ethernet standard, and communicate with other devices.

PAC advantage analysis

Integrated hardware and software are also an advantage when programming: The Integrated Development Environment (IDE) is used to program the PAC including a generic tagname database that all development tools can recognize. PAC uses a single software package instead of multiple software packages from different vendors to address existing and future automation needs.

Another advantage of PAC is that the upgrade of the control system is very simple. Modular processor hardware is easily replaced without the need to unplug sensors and energized wiring. Due to its small size, a PAC can save valuable space for the cabinet.

PAC has modern network and communication capabilities and access to information in real time. This in turn makes data collection more accurate and timely, and therefore more valuable for commercial use.

As for the price, PAC can provide a variety of economic advantages:

  1. Due to the lower cost of hardware, less time is spent on development and integration, so the total cost of the control system is reduced. The price of buying a PAC is often more economical than adding a similar function to the PLC.
  2. Due to the extension of the application range of automation systems (also known as its expertise), PAC has improved in terms of return on assets, lower life cycle costs, and lower total cost of ownership (TCO).
  3. Improved cash flow: Adding I/O as a separate module means that only a minimum number of modules are needed during the initial development phase, and the remaining modules are added before the end of the project.


Remote Terminal Equipment (RTU) is similar to a controller device and is installed at a remote location to collect sensors and other data. After decades of popularity, RTUs are commonly used as a network for monitoring and data acquisition (SCADA systems), and RTUs send data to SCADA. The RTU receives information from the SCADA master and manipulates the field devices at the remote location.

RTUs are deployed primarily in remote geographic areas to monitor, collect and control remotely dispersed equipment such as pipelines, wells, cranes, or telecommunications facilities. Traditional PLCs do not have natural communication capabilities in these types of applications. In addition, PLCs generally do not provide harsh field conditions and do not have the flexible I/O configuration required in most RTU applications.

In general, RTU emphasizes the development of its communication functions for harsh environments and flexible I/O configurations.

However, traditional RTU communication capabilities are often outdated because they were developed during private radio or leased private communication networks. Today’s open, IP-based wired and wireless local and wide-area networks are more flexible and less expensive. For this reason, the use of outdated RTU technology is not commercially or technically significant when retrofitting existing RTUs or executing new applications.

Conversely, PACs offer superior communication capabilities, general purpose I/O options, wide temperature and vibration specifications, and use today’s leading communications standards. These features make PAC a good alternative to traditional outdoor RTUs, especially old networks, proprietary networks, etc. due to increased maintenance costs or outdated networks.

data collection

The Data Acquisition System (DAQ) is based on PC equipment and provides fast signal acquisition, basic signal debugging, data retention and limited networking capabilities. Most DAQ systems are PC-based and have limited use in physical or remote locations. Most DAQ systems prefer to stay in the lab rather than outdoors.

PAC provides versatile and flexible signal detection, debugging and multi-line. It has a powerful processor and a large amount of memory, and the raw data obtained can be accumulated, proofreaded, or otherwise processed before being transferred to the database for other applications (for example, converting raw data into engineering units).

In addition, the data can be saved locally. Since the PAC is not a PC, unlike a PC that requires a high cost, it can be deployed at will in the field. So PAC is a good choice.

Various industrial automation suppliers now offer PAC or similar PAC products. In some cases, these products are more like PLCs, and in other cases they are more like industrial PCs. As mentioned earlier, the PAC is integrated with these devices so that devices that focus on PLC or PC functionality may not be suitable for your application needs.

When evaluating a PAC or similar PAC automation controller, you only need to consider this empirical method: In order to meet your requirements, do you need to add additional processors, network interfaces or middleware to make the controller have similar characteristics to PLC or PC?

If so, check to see if the controller is more compliant with the PAC features described above.

Some vendors may have been in business for any product. Many vendors have recently introduced new PAC or PAC-like products, and several candidate companies, including OPTO22, have proven their power with outstanding sales performance a few years before the PAC entered the mainstream.

In 1990, 11 years before the birth of the PAC concept, Opto 22 introduced the prototype of the PAC, a computer-based hardware device, the mistic controller. The Opto22SNAPPAC system is now based on mistic. Other PAC equipment applications include semiconductor processing, raw material processing, water and water treatment, and pipeline monitoring.

In summary, PAC provides a compact controller with advanced control functions, network connectivity, device interoperability, and enterprise data integration capabilities that can be found in PLC or PC-based controllers. With these features, PAC has become an integral part of meeting industrial needs in modern industrial applications.

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