Interfaces for the Future of Production

The “Plus & Produce” vision requires a new generation of interfaces that are significantly more communicative than before. For WEISS, the OPC UA and MQTT transmission standards are just as important as developing product interfaces that offer the customer maximum flexibility.

 

Connect and use – what has been the normal routine with computers for years, thanks to USB, and allows for problem-free immediate use of nearly all peripheral equipment is still a pipe dream in the industrial production environment. Even in ultra-modern production, the various control systems, communication protocols and fieldbus systems still have to be managed, which entails a great deal of configuration work – both during start-up and when making adjustments to the production system.

The costs associated with this increase the pressure on machine and system manufacturers to increase the standardization degree of their products. At the same time, however, they need enough room to realize customer-specific product features, which also sometimes occur through interfaces. It is a challenging balancing act that significantly influences the competitiveness and future viability of machine and component manufacturing.

OPC UA and MQTT – communication standards for networked productionA uniform basis of communication is required to network machines, peripheral equipment, software and IT within the context of the “smart factory.” Various interfaces and protocols are available for this. For example, condition monitoring can be used to transmit and directly visualize status data via Profinet, EtherCAT or EtherNet/IP.

More detailed information can be called up via OPC UA and MQTT. These are currently considered the two most important communication standards in production because they work independently of the manufacturer. According to a VDMA study, they also help production companies with important transformation goals, such as:

• dissolving proprietary interfaces
• realizing plug & produce through standardized communication
• reducing the work involved with integration
• producing more attractive products with greater customer benefits
   

1. Open Platform Communications – Unified Architecture, in short: OPC UA
OPC UA is an open interface standard for secure industrial communication from machine-to-machine or PC-to-machine and other systems. The most important goals of OPC UA are platform independence and interoperability.

To implement a “global machine language” vision, OPC UA is combined with complementary technologies and standards, such as with Ethernet, Ethernet TSN or Ethernet ALP, as well as with protocols such as UDP/IP or TCP/IP.

One of the advantages of OPC UA is that security characteristics and IT mechanisms for authentication, encryption and signing are already implemented in the standard. In connection with the semantic description of machine data, the solution is therefore suitable not only for the secure integration of machine data streams but also for machine learning applications and for realizing digital IoT services.

In the future, OPC UA will dominate the field level and meet all industrial automation requirements as an interoperable communication solution. Additional costs due to complex software development or constant fiddling with cumbersome gateways would then be a thing of the past.

2. MQTT – Message Queuing Telemetry Transport
MQTT is an open network protocol for machine-to-machine communication, which allows for the transmission of telemetry data in the form of messages. Devices suitable for transmission range include sensors and actuators, cell phones, embedded systems in vehicles, laptops and workstations.

The devices are connected via a central server, which continuously provides the state of all connected devices. This makes MQTT particularly well-suited for connections across large distances and in networks that are susceptible to interference. MQTT is also open source.

Many tools are available to download free of charge, which is a significant advantage that explains why MQTT is now widespread. Moreover, MQTT is easy to implement – while the specification for OPC UA is 1,250 pages, it is only 80 pages for MQTT.

MQTT and OPC UA are equally suitable for establishing a robust security architecture. The strengths of MQTT lie primarily in its reliable data transmission across large distances, while OPC UA performs especially well when it comes to real-time communication within a factory building. The respective strengths of the communication protocols can be combined when both standards are used in parallel.

Modules for each interface
As a component manufacturer, it has always been natural for WEISS to apply industry standards. “In the Integrated Assembly Solutions (IAS) department, we work together with partners such as VDMA on continuously developing OPC UA. On the market, we repeatedly come across MQTT especially in the context of customer requests. We then use this interface as part of these specific projects as well as in developing our new products for transmitting status data,” says Christian Göltl, product manager for Controls and Digitization at WEISS.”

However OPC UA and MQTT are not the end of the story of interfaces at WEISS. After all, in addition to the manufacturer-independent interfaces, customer interfaces also play an important role in the portfolio strategy.

Take the rotary indexing tables, for example: There are four standard interfaces here alone with the mechanical motor flange, electric motor terminal board, control panel and control system. For customers, this orientation towards the standard offers several advantages because they can flexibly configure their peripheral equipment with modular WEISS components to meet their needs, or they can also purchase them through third party suppliers. "As a component manufacturer, we need to offer this interoperability to appeal to a large group of customers. We do not have the market power to dictate interfaces,” explains Christian Göltl.

Work first, then the visions
Interoperability is not just a defined customer requirement, though. It also causes problems with relative frequency, namely when it is missing. This can happen when customers incorrectly wire a rotary indexing table to the production system. WEISS does offer various terminal panels for holding individual wires, and the connection can also alternatively be established via a LAN cable.

However, regular errors occur here too because the configuration does not occur automatically, Instead, the IP address and subnet mask must be entered manually. “Of course we want to get our customers excited about visions and new digital possibilities. But we can only do that once we have taken care of these two pain points,” says Christian Göltl.

To remedy this as quickly as possible, on the one hand WEISS will create more tutorials and expand its knowledge database further – in other words, offer more self-help. On the other hand, however, WEISS is also looking for new transmission path for the wireless communication of status data, which can be used to identify problems caused by wires. "The rotary indexing tables from WEISS are installed in the heart of automation and assembly plants. This means that they may not be directly accessible under certain circumstances. NFC is an interesting technology for us, especially within this framework. Customers who use a rotary indexing table with WEISS control system read the data from the control system.

If the indexer is operated without a WEISS control system, the user can request the status data via NFC as needed without having to mechanically remove the cover of the switching cam, for example. In this sense, NFC is a simple technology that does not require any additional interface or app. It easily transmits data between different devices,” explains Christian Göltl. "By using NFC, we are preparing for future digital services and making it easier for the customer to integrate their components into the WEISS World.”

Interfaces for life cycle data
WEISS is also using wireless communication to meet customer requests to receive more operating and status information about their rotary indexing table, such as in the context of condition monitoring or predictive maintenance. “Once we have created a database for this, we can use the corresponding algorithms to also meet the request for predictive maintenance,” explains the interface expert from WEISS. The path to innovation also includes installing sensors that detect status changes and anomalies. “This means that our customers receive life cycle data in sufficient granularity based on relevant measured variables, which we provide directly from the component.”

These and many other developments are made possible through a clear demarcation between standardization and individualization. In WEISS’s case, this means that all areas beyond the component are served as a standard. Within the component, however, WEISS uses its domain knowledge in a functional way to ensure that sensors record the correct measured variables, as well as for continued developments in the direction of predictive maintenance and other digital services. "Here, within in the scope of our domain knowledge, there’s nothing that is created as a standard,” says Christian Göltl. “Being able to supply this data ‘from the bottom up,’ so to speak, that is, from the component, is our competitive advantage and our USP.”