OPC UA has been adopted as a recommended standard for Industry 4.0. The spread of OPC UA is progressing as a global interoperability standard that supports manufacturing and manufacturing DX (digital transformation) in the digital era.

The Industrial Interoperability Standard

OLE (Object Linking and Embedding) for Process Control (OPC) Unified Architecture (OPC UA) is an interoperability standard for the secure and reliable exchange of data in the industrial automation space and in other industries. This standard was released by the OPC Foundation in 2008 and later adopted as IEC 62541.

In addition, this standard is integrated with the IEC 61131-3 PLC programming standard to reliably exchange field data between machines and IT systems like SCADA or MES, serving as a basis for the packaging standard PackML (ANSI/ISA-TR88) for the food and household goods industries and the standard for exchange of data between injection molding machines (EUROMAP 77).

Use Case 1: DA to UA

Many of the first-generation OPC technologies — OPC Data Access (DA) — have been widely deployed in supervisory control and operation monitoring of factories. As these systems continue to be upgraded, the adoption of OPC UA increases (Figure 1). There are three key pieces:

  1. The direct connection with the control devices, such as a PLC, is enabled and the system configuration becomes simplified.
  2. The ability to exchange not only simple numerical values and memory data but also structured data and information with meaning.
  3. Security can be improved.

The increasing choice of SCADA, PLCs, and controllers that support OPC UA is also a driver for adoption.

Use Case 2: Securing Manufacturing Data

To realize industrial IoT and Connected Factory, cybersecurity at manufacturing sites is a crucial issue for connection between industrial automation systems and the host IT system, remote access maintenance, and advanced use of the Internet to pursue productivity improvements.

OPC UA security is based on recognized standards that are also used for secure communication on the Internet and satisfies the three security requirements: confidentiality, integrity, and availability. Integrity by digitally signing the messages and confidentiality by encrypting the messages ensure a secure connection between automation systems and IT systems.

In order to simplify the implementation of data integrity, OPC UA — which supports digital signatures — is being adopted for this purpose. OPC UA provides secure connection and data transmission, which is one of the reasons it is recommended for communication technology for Industry 4.0.

Pharmaceutical and automotive parts manufacturers are increasingly attaching great importance to safe and secure manufacturing. They started to use the system to ensure that production data has not been manipulated, proving that products have been produced correctly.

Use Case 3: Standardized MES Connection and Traceability

Figure 2. Machines and devices of various manufacturers in one production line may not have a standardized connection method between the upper system and the machines. OPC UA connection with the quality traceability database can be standardized with the database direct connection feature.

In one customer’s production line, many machines and devices of various manufacturers were installed and the connection method between the upper system and the machines was not standardized. The connection with the quality traceability database was standardized with the database direct connection feature. This system has been deployed in each plant as the global standard interface (see Figure 2).

There is also an application where OPC UA is used in a machine. In the final inspection of automotive parts, the Omron NX701 machine automation controller collects and analyzes the high-speed analog signals of tens of kHz required for judgment, stores all inspection results in a traceability database (SQL), displays the status and results using SCADA, and controls the transfer of the data. A direct connection to the database is used to collect and analyze the analog signals and store them in the database and OPC UA is used to connect to SCADA to display the status and results.

Figure 3. The NX701 Series machine automation controller can simultaneously and directly connect to two host systems: an OPC UA server and a database.

The controller is designed for equipment and processes that require high speed, high accuracy, and large-scale control such as high-speed filling machines and packaging machines for drinks and pharmaceuticals. Example processes include winding and laminating in the manufacturing of automotive lithium-ion batteries. In addition to high-speed/ high-accuracy control, such equipment and processes also require MES and production system connectivity and their data must be stored in quality traceability systems (Figure 3).

Use Case 4: Machine Interface

In order to remotely monitor an excavator used in an underground mine, the excavator and the SCADA in the monitoring room are connected by OPC UA. OPC UA is appreciated here because it is easy to connect and can be used without any complicated knowledge.

In an application of operation monitoring of metal machinery, OPC UA is adopted to gather and visualize the operation information of the machine tool including a CNC. They are installed in a large number of metal parts processing lines, together with the information of the peripheral devices controlled by a PLC and the information of the operating environment such as power and temperature. The key point is that the information of both the CNC and the PLC can be collected and managed by one mechanism (OPC UA).

This article was written by Minoru Oka, Product Manager at Omron (Kyoto, Japan) and Chair of Marketing for the OPC Foundation Japan. For more information, visit here .


Motion Design Magazine

This article first appeared in the October, 2021 issue of Motion Design Magazine.

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