Author Introduction:Wang Xin, Master’s degree, operates the Hydraulic Pirate public account,AutomationStudio technical sales, and has been engaged in the design and simulation of non-standard hydraulic systems for a long time.
Nowadays, hydraulic systems or hydraulic components often present you with a bunch of incomprehensible protocols like IO-LINK, EtherCAT, etc. Is it because the salespeople are too ‘showy’, or is our own knowledge system too narrow? Neither, it should be that our hydraulic media work is not done well enough… So today we will sort out the various communication methods used in hydraulic systems or hydraulic components.
01 USB
USB, as a widely used standard communication interface between computers and external devices, relies on differential signals to transmit data, covering various modes including high-speed (such as USB 3.0 and above) and low-speed (USB 1.0, USB 2.0, etc.).
In the field of proportional servo valves, it mainly undertakes connection tasks such as parameter configuration and fault diagnosis between devices and computers.
In terms of application scenarios and characteristics, USB is extremely convenient. During equipment development or on-site maintenance, technicians can connect the proportional servo valve to the computer via the USB interface. Its advantages are significant, such as the theoretical transmission rate of USB 3.0 reaching 5Gbps, and good stability for short-distance connections; however, its shortcomings cannot be ignored, as the transmission distance is limited, usually not exceeding several meters, and it is not very suitable for real-time control communication.
02 IO-Link
IO-Link is a sensor/actuator interface standard used for device communication in automation systems, based on a point-to-point communication model, which transmits data via short pulses, allowing field devices (such as proportional servo valves) to connect to higher-level automation networks. In terms of application scenarios and characteristics, it is widely used in industrial automation scenarios, especially in small devices or compact automation units.
Its significant feature is that it simplifies wiring; a single cable can achieve power and data transmission, and it can automatically recognize connected devices. Although the data transmission rate is relatively low, it can meet the needs for some proportional servo valve control scenarios where speed requirements are not strict, such as valve control in simple material handling equipment.
03 Bluetooth
Bluetooth is a short-range wireless communication technology that operates in the 2.4GHz frequency band, using frequency hopping technology to avoid interference, and establishes connections through paired devices. In the communication of proportional servo valves, wireless control can be achieved through Bluetooth modules.
In terms of application scenarios and characteristics, it is suitable for situations that require flexible mobile device control of proportional servo valves, such as debugging experimental equipment or some portable device scenarios. The advantage of Bluetooth lies in its convenient wireless connection, which does not require complex wiring; however, its transmission distance is relatively short (generally around 10-100 meters, specifically affected by power and environment), and transmission stability is easily affected by other wireless signals in the environment. Additionally, the transmission rate is limited, and there may be delays when dealing with large data volume real-time control.
04 CANopen
CANopen is a high-level protocol based on the Controller Area Network (CAN) bus. The CAN bus itself is a multi-master serial communication protocol, and CANopen defines communication objects, device models, and application layer protocols based on it, using identifiers to distinguish different messages, and has good error detection and handling mechanisms. In terms of application scenarios and characteristics, it is widely used in industrial automation and automotive fields. For proportional servo valves, it can easily integrate into CANopen-based automation systems. Its advantages are prominent, with good real-time performance, supporting simultaneous communication of multiple devices, high network reliability, and a communication rate of up to 1Mbps, which is sufficient to meet the real-time needs of multiple valve collaborative control of proportional servo valves in automated production lines.
05 Powerlink
Powerlink is a real-time Ethernet protocol that uses Time Division Multiple Access (TDMA) communication method. In each communication cycle, it is divided into equal-length time slots, allowing different nodes to send and receive data in specific time slots, thus ensuring real-time and deterministic communication. In terms of application scenarios and characteristics, it is mainly used in industrial automation control systems with extremely high real-time requirements. For proportional servo valves, it is often used in high-precision motion control scenarios. Its features include high-precision synchronization performance, achieving microsecond-level synchronization accuracy, and a communication rate of up to 100Mbps, ensuring the precision of coordinated actions of multiple proportional servo valves, such as in high-precision machine tools or high-speed automated packaging equipment.
06 Profinet
Profinet is an automation communication standard based on industrial Ethernet, adopting a producer-consumer model, connecting devices via Ethernet switches, supporting real-time (RT) and isochronous real-time (IRT) communication modes, with IRT mode providing high-precision synchronous communication. In terms of application scenarios and characteristics, it is widely used in large industrial automation systems. For proportional servo valves, it can easily integrate with other automation devices into a unified network. Its advantages are numerous, with excellent openness, compatibility with various devices, and a communication rate of 100Mbps or higher. In complex industrial production processes, such as automotive manufacturing production lines where multiple robots and valves work cooperatively, it can achieve efficient control.
07 EtherCAT
EtherCAT is a real-time industrial Ethernet technology that uses a unique “data frame crossing” mechanism. When the data frame passes through each device node, the node can quickly extract and insert its own data without stopping the data frame, greatly improving communication efficiency. In terms of application scenarios and characteristics, it performs excellently in high-speed, high-precision industrial automation equipment control. For proportional servo valves, it can achieve extremely fast response speeds. Its characteristics are distinctive, with short communication cycles (up to microsecond level), high transmission rates (up to 100Mbps or more), and the ability to connect a large number of devices, widely used in large automated production lines or complex industrial robot control, such as in high-precision equipment control in the manufacturing lines of 3C products (computers, communications, and consumer electronics).
08 Ethernet/IP
Ethernet/IP is an industrial Ethernet protocol that encapsulates the Common Industrial Protocol (CIP) in Ethernet frames for transmission, based on an object-oriented communication model, supporting various communication methods, covering explicit and implicit messages.
It is widely used in the industrial automation field, especially in factory automation and process automation integration. For proportional servo valves, it can communicate smoothly with other Ethernet/IP-based devices. Its openness is good, facilitating integration with devices from different manufacturers, and the Ethernet infrastructure can provide high-speed data transmission (100Mbps or higher), suitable for data transmission and control in large automation systems.
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