Sensor manufacturers, controller manufacturers, equipment manufacturers, and manufacturers are often faced with the most diverse selection of bus protocol options and on-site device-level interface choices when considering their own devices for intelligent and automated design. How to effectively resolve the compatibility between the protocols and the unity of the sensor interface has become a major issue for major sensor and controller manufacturers.

At present, there are various industrial control computers, PLCs, and bus product manufacturers on the market. There are a wide variety of existing bus protocols. The main areas of factory automation include: Ethernet, CANopen, DeviceNet, PROFINET, PROFIBUS-DP, PROFIBUS-FMS, etc.; there are mainly process automation fields. :FoundationFieldbus (FF), PROFIBUS-PA, P-NET (ProcessautomationNet), etc.; and each protocol is independent and incompatible with each other, which brings a lot of inconvenience to the customer's application. This is for the customer-oriented market status. It is undoubtedly unfavorable for the long-term stable development of the industrial control industry. Under such a background, the revolution of an industrial fieldbus technology is imperative. How to achieve multi-network, multi-protocol interconnection and barrier-free operation is undoubtedly the development direction of industrial fieldbus technology.

The Ethernet network is undoubtedly the result. Open Ethernet is the most successful network technology developed in more than 20 years, and has led to a revolution in information technology. With the development of network technology and the efforts of major network companies and automation companies (such as Siemens), it can be foreseen that Ethernet/IP will enter the industrial control system very quickly, just as PCs entered the field of industrial automation. Network at all levels.

At present, the industrial fieldbus is gradually shifting to the Ethernet network. PROFINET is increasingly widely used and is one of its performances. As a strategic technological innovation, PROFINET provides a complete network solution for the field of automation communication, including such things as Real-time Ethernet, motion control, distributed automation, failsafe, and network security are hot topics in the current automation field, and as a cross-vendor technology, it is fully compatible with industrial Ethernet and existing fieldbus (such as PROFIBUS) technology To protect customers' existing investment. However, PROFINET is only a small step in the technological revolution, and there is still a long way to go in the future.

The above describes the situation of the fieldbus protocol, steering sensor, and well-known sensor manufacturers in various automation fields all have the technical strength to produce and manufacture sensor products supporting the bus protocol. However, how to achieve maximum compatibility with various existing bus communication technologies is a problem that all manufacturers have to face, and it is also the direction of future sensor technology development. In order to better set parameters and store configuration data for control and indication, many sensors and actuators have been equipped with microprocessor systems and achieved point-to-point access to the control layer through communication technologies such as HART, IO-Link, etc. .

Therefore, I think for each sensor supplier, not only products that directly support the common industrial fieldbus protocol, such as: rotary encoders that support CANopen, PROFIBUS-DP, DeviceNet protocol, linear displacement sensors, and pressure, temperature, and flow Such as measuring sensors, etc.; it is necessary to constantly develop and manufacture products that support point-to-point protocols such as HART and IO-Link. Such products have independent communication technologies and are compatible with mainstream general-purpose network architectures. Meets the need for sensor standardization and commercialization.

For the selection of sensor support protocols, versatility and practicality are the most important. Now that the amount of information between sensors has surpassed that of computers or other applications, it has become the mainstream of information exchange. The efficient integration of sensor networks and the Internet enables people and things to be realized. Interconnected with things. Therefore, the technology of the sensor core chip and the sensor network accessing the Internet will be the bottleneck that will be the priority for IT advancement in the next few years. In this way, how to better integrate the sensor with Zigbee communication technology, RFID communication technology, WI-FI communication technology, and 2G and 3G communication technology has become the main direction of future sensor development.

Under the premise that the existing production R&D technology can be satisfied, it is necessary to manufacture sensor/actuator products that support the mainstream industrial fieldbus communication protocol on the market as far as possible so as to be able to continuously adapt to the increasingly diverse market needs and better There is a place in the fierce market competition so as to improve the competitiveness of its products and better meet the needs of customers at different levels and industries.

In recent years, major sensor manufacturers have been pursuing improvements in sensor functionality and intelligence in order to promote the continuous development of automation. However, the interface is always the same and there is no big breakthrough. In order to achieve the unity and transparency of the field device layer interface, in 2004, major mainstream sensor manufacturers established a new association, focusing on the development and promotion of IO-Link interface technology. Pepperl+Fuchs is one of the key members. Until 2011, with the introduction of various types of IO-Link interface sensors from Pepperl+Fuchs to the Chinese market, the IO-Link interface technology was considered to be a genuine entry into the Chinese market.

In the current factory automation network, our most common sensors are field devices for discrete signals (such as NPN, PNP switching signals) and continuous signals (such as current and voltage analog signals). The transparent data exchange only stays at the control level, between the programmable controller and the programmable controller, and between the programmable controller and the host computer. When the IO-Link interface technology was introduced, the sensor provided process data (discrete signals and continuous signals), and also increased the interactive function of maintaining data.

The IO-Link interface technology is a new generation of point-to-point communication technology. Its advantages are unified access modules, unified installation wiring, unified software configuration, unified data structure, maintenance-free plug-and-play, and retention criteria I. /O interface. Specifically, a unified access module: When the user selects a programmable controller input/output module, the user does not need to consider the NPN or PNP module, the switch or analog module, a 3-wire or 4-wire module; the programmable controller end Use a unified IO-Link master module. Uniform installation wiring: When the user is designing, there is no need to consider the design of 2-wire, 3-wire, 4-wire or even 12-wire, and there is no need to consider the selection of pin number, wire color and shield wire; the sensor end is a unified 3-wire design (power supply is positive , Power Negative, IO-Link Signal Line). Uniform software settings: The data exchange and parameter setting between the sensor and the programmable controller can be easily realized through a unified device parameter management text (IODDS). The user can parameterize and monitor the sensor using universal IODDS text or using sensor manufacturer-defined user-friendly IODDS text. Maintenance-free plug-and-play: In the traditional interface mode, the user needs to reset the sensor according to the site conditions when replacing spare parts. The sensor user with the built-in IO-Link interface only needs to import the previously saved configuration file into the sensor. .

The next-generation IO-Link interface technology enables automatic download of parameters after the sensor is attached, without user intervention. Retain the standard I/O interface: Considering the replaceability of the current network, when designing the IO-Link interface, the input port of the IO-Link master module of the programmable controller can be customized, and the conventional sensor can be connected. Connect IO-Link sensors; the same IO-Link sensor interface can also be customized, can be used as a conventional NPN / PNP sensor, also can be used as IO-Link sensor to ensure compatibility with the current network and equipment. We have reason to believe that in the near future, IO-LINK interface technology will inevitably become the leader in field device layer interface technology for the entire sensor industry.