HomeOperator PlatformIntegration with machines via OPC / OPC UA

Integration with machines via OPC / OPC UA

How many different machines and PLCs are in your production?

Reading machine data in real time is key to achieving high OEE. For many companies, getting reliable, comparable data from machines is a major challenge.

Companies using the Operator Platform, have at their disposal the Operator Datalogger solution which helps organize and give business context to data from various machines and equipment.

Integracja z maszynami za pomocą standardu OPC/OPC UA

Use proven solutions to acquire data from machines.

To achieve this, we use a proprietary Operator Datalogger solution. Through the use of, among other things, OPC / OPC UA standard, we can connect to a wide range of machines or industrial equipment.

Through simple integration with machines, our customers are able to monitor in real time the efficiency of machines and production lines, conveyors, palletizers, robots or manipulators.

In addition to improving efficiency, real data from the shop floor is also an invaluable source of information on process capability and product quality. To acquire them, we integrate with equipment such as i.e. scales, weighing machines, thermometers, spectrometers and X-ray or foreign body detectors.

The Operator Datalogger tool provides the ability to communicate with machines quickly and easily by using the OPC and OPC UA standard.

Operator Datalogger provides seamless integration with machines and a wide range of shop floor equipment and facilities, enabling data exchange during the production process. Operator offers standard integration – regardless of equipment vendor, to unify visibility of production process execution across the enterprise.

Proven, fast connection to the machine.

Operator Datalogger (ODL) is a Windows service that is part of the Operator Platform. It is designed to run in the background – it usually runs on the same computer where the OPC server is running. Its purpose is to create OPC / OPC UA subscriptions configured in the Operator Platform database. Based on these subscriptions, the service will conduct reads and writes between the OPC Server and the Operator Platform Database. Since ODL runs independently, it can be installed on the same machine on which the OPC server runs, while the Operator Platform server runs on another computer on the same network. This is advantageous because it doesn’t cause DCOM configuration problems that can be troublesome when remotely connecting to an OPC / OPC UA server.

What data is needed to monitor OEE in real time?

Article What is the OEE indicator provides extensive information on the OEE indicator and its individual components. However, to answer the above question, it is worth recalling that the OEE indicator is the product of three components:

OEE = Availability × Productivity × Quality

To monitor the OEE value in real time, therefore, we need relevant data for each of these components:

  • Availability – in order to monitor it, information about the status of the machine – whether it is running or stopped – is required. For the availability information to be complete, the stop reason code must also be added. This information can be retrieved from the machine or completed by the operator.
  • Productivity – here the information about the current amount produced, which is most often provided to us by machines in the form of a “counter,” is sufficient. Based on this, the current speed of the machine is calculated, which can be compared with the nominal speed – indicated for the machine and/or product.
  • Quality – requires information on the amount of waste generated. As with the current amount produced, this information is most often obtained by means of a “counter”. For most manufacturing processes, the impact of the quality component on the OEE value is small, so it is reasonable for operators to enter this value on the panels of the MES system.

In practice, the mere information about the current amount produced can provide a good basis for monitoring OEE in real time. Based on it, the Operator Platform will be able to identify the machine’s idle period and calculate its availability. Operators will be informed of identified periods of idleness or lower productivity and will be able to classify them using dictionaries of reason codes. The amount produced from the machine can also be classified manually as good products, waste or sent for repair. As a result, with only one piece of information provided on an ongoing basis from the machinery, we are able to reliably assess its ongoing performance using the OEE indicator.

What you should know about integrations

What is the OPC UA standard?

OPC UA stands for Open Platform CommunicationUnified Architecture. It was developed by the OPC Foundation and is currently the most popular data exchange standard in the industry. It helps create solutions in which individual sensors, devices or machines can easily communicate with each other, and with other IT systems used in enterprises.

It is a key tool in the Industry 4.0 concept. TheReference Architecture Model for Industry 4.0 has already recommended OPC UA (described in the IEC 62541 standard) as the only method for providing a communication layer since 2015.

The predecessor of the OPC UA standard is the so-called Classic OPC.

What are the key advantages of OPC UA?

It is an open standard, so it is independent of the hardware vendor, the programming language used to write the application or the operating system. The OPC UA standard can be implemented by a wide range of devices and applications, such as PLCs, sensors, embedded systems, web applications, gateways or mobile devices.

OPC UA is also suitable for use over the Internet. By using mechanisms such as https to communicate between the server and clients, OPC UA performs well in complex network environments and does not require special configuration of firewalls or routers. As a result, with OPC UA, industrial machines and equipment can be equipped with secure methods to communicate over the Internet.

An important advantage of OPC UA is information modelling (Information Modelling). Through it we can send more complex data structures, for example, in addition to the measurement value itself, we can receive information about the unit of measurement, the type of sensor, its configuration, etc…. It is worth noting that despite the possibilities offered by Information Modelling, OPC UA still supports simple communication of the type DA (Data Access), HA (Historical Access) or A&E (Alarms & Events), about which more in the section on Classic OPC.

A major advantage for those working with the OPC UA standard is the implementation of service-oriented architecture(SoA). This makes the creation and configuration of OPC UA-based solutions clearer, more user-friendly and the solutions themselves easier to maintain.

By using modern communication protocols such as https, OPC UA significantly simplifies integration between systems. A sensor equipped with an OPC UA Server can communicate directly with a higher-level system, such as MES(Manufacturing Execution System), leaving out at least the PLC or Scada layer, which would have been necessary for older standards.

Solutions based on the OPC UA standard are scalable – its implementation can include a single OPC UA controller and data server, as well as connect all machines and equipment within a corporation managing dozens of factories. The Fraunhoffer Institute had already developed a 10kb OPC UA server instance in 2012.

What is the Classic OPC?

The so-called Classic OPC is the predecessor to the OPC UA. It was implemented so that widely used HMI(Human-Machine Interface, used for machine control) applications that were created for the Windows platform would not have to communicate directly with industrial devices. This solved the problem of installing many different incompatible drivers on Windows, which were required by various devices. The unifying layer for communication thus became the OPC Server (Classic), which allowed applications such as HMI, Scada or Historian (OPC clients) to communicate with only one service. Classic OPC provides interfaces such as:

  • OPC DA(Data Access) which allows access to read and write data in real time and thus, for example, to monitor process variables
  • OPC HA(Historical Access) which provided access to already stored, historical data
  • OPC A&E(Alarms & Events) which allows receiving information about events and alarms.

To simplify the work on the protocol, it was decided to use tools provided by Microsoft:

  • COM(Component Object Model) – which allows communication between different applications.
  • DCOM(Distributed Component Object Model) – which allows communication between applications running on different computers on the same network.

As a result, the entire Classic OPC specification is dependent on the Microsoft ecosystem. Both the server and OPC clients must run on the Windows operating system. However, this was not a big problem, as OPC clients and servers were not then running on embedded devices, with other operating systems (e.g. Linux), in the cloud or on mobile devices.

Another drawback of Classic OPC is that it can only communicate within a single network – which ruled out communication via the Internet.

What is a PLC?

A PLC is a small industrial computer that is most often mounted on the DIN rail of the control cabinet of a device, machine or line. The name PLC comes from Programmable Logic Controller, which can be translated to Programmable Logic Controller. It is used to automate the control of machine operation. The most important components of PLC devices can be schematically described as:

  • The interface of the device, with which the technician can connect to it, upload a new program or check the operating parameters. Programs uploaded via the interface are created in dedicated applications, and these are the programmable logic of the device.
  • Input module – to which we connect devices such as various sensors, switches, meters, etc.
  • Output module – which allows you to control operating parameters and usually connects to devices such as relays, valves, lights or motors.
  • HMI – is not a mandatory part of the PLC device, but they often have a simple display and a set of buttons that allow you to change the program, view operating parameters or reset the device.
  • Communication ports – thanks to which the PLC device is able to communicate with other devices or IT systems, such as OPC Server or SCADA class software. Modern PLCs are able to use modern methods such as REST interfaces and the MQTT protocol for this purpose.

Thanks to the programs uploaded to the PLC, the device can analyze signals from the input module and control the parameters of devices connected to the output module. As a result, we are able to automate all or selected parts of the production process and eliminate the need for human supervision. The biggest advantages of automating the process with a PLC are:

  • Accelerate production and automatically respond to changing operating conditions.
  • Ability to alert on problems.
  • Ensure the appropriate standard and quality of production and the correctness of its parameters.
  • No need to rely on the expertise of machine operators.
  • Access to precise, up-to-date data that can be analyzed in other information systems.