Industrial controller with LAN wake-up function

Abstract

An industrial controller (100) operable in an operating mode and a sleep mode, the industrial controller comprising: a driving module (108) configured to drive an industrial appliance (10); a network interface (106) configured to communicate with an external network (20); and a power module (104) configured to directly supply power to the driving module in an operating mode. The industrial controller (100) also includes a power switch (102) connected to the input power source (30) and configured to power the power module in an operating mode and to power the network interface but not the power module in a sleep mode. In the operating mode, the network interface (106) may be powered by the power module (104) or the power switch (102). A method of operating an industrial controller (100) is also provided.

Description

Technical Field

[0001] The present disclosure relates to the field of industrial control and in particular proposes a novel industrial controller with a LAN wake-up function. Background Art

[0002] The so-called Wake-on-LAN functionality can help save energy when temporarily shutting down a portion of an automated industrial production line. Under such conditions, the industrial controller associated with the shut down portion of the production line is powered off and enters a sleep mode. The industrial controller remains in sleep mode until awakened by a wake-up signal or wake-up message received through a communication network connected to the industrial controller. In production lines equipped with centralized safety functions that regularly monitor or poll safety-critical actuators and sensors, it is not always possible to implement a power-off strategy. In fact, although the safety actuators and sensors in the sleeping industrial controllers are only voluntarily powered off under conditions that do not pose a safety risk, they will still be considered absent or malfunctioning.

[0003] The prior art includes various proposals to avoid this inconvenient situation. First, and to some extent beyond the technical field of the present application, US20150006930A1 discloses an imaging device with a power saving mode that cuts off power from the AC mains during periods of device inactivity. In order to allow external monitoring of user-related events while the AC mains is cut off, power is drawn from an alternative power source separate from the AC mains to power a microprocessor unit (MPU) configured to respond to monitoring inputs. When such monitoring inputs are received, a switch is used to reestablish connection with the AC mains so as to provide AC power to the device. The alternative power source may include a battery or a capacitor.

[0004] A second example is EP2518935A1, which discloses an automation network having a control unit, a network switch and an automation unit without energy management. The automation network comprises a Power over Ethernet (PoE) connection powered by the network switch, and a normal Ethernet connection. Although the network switch is always powered on, the automation unit can be selectively powered off. In order to wake up the automation unit, the control unit sends a LAN wake-up signal to a LAN wake-up module in the automation unit. The LAN wake-up module responds by connecting the fully automated unit to an external power supply, such as 24V or 230V.

[0005] It may be desirable to implement a wake-on-LAN functionality that is compatible with a centralized security chain while reducing structural complexity and / or usage of hazardous battery and capacitor materials. Summary of the invention

[0006] An object of the present disclosure is to provide an industrial controller configured to drive an industrial appliance, wherein the industrial controller is capable of being monitored by a safety chain even in sleep mode. Another object is to provide a method of operating an industrial controller in an energy-saving manner. A particular object is to propose such an industrial controller for driving an industrial robot. Preferably, these objects should be achieved with limited structural complexity. More preferably, the objects should be achieved with limited use of batteries and capacitors.

[0007] At least some of these objects are achieved by the invention as defined in the independent claims.The dependent claims relate to advantageous embodiments of the invention.

[0008] In a first aspect of the present invention, an industrial controller capable of operating in a working mode and a sleep mode is provided. The industrial controller includes a drive module configured to drive an industrial appliance; a network interface configured to communicate with an external network; and a power module configured to directly power the drive module in the working mode. According to the first aspect of the present invention, the industrial controller also includes a power switch connected to an input power supply. The power switch is configured to power the power module in the working mode, and to power the network interface but not the power module in the sleep mode.

[0009] Due to the above behavior of the power switch, the desired LAN wake-up behavior can be achieved without providing an alternative power supply inside or outside the industrial controller. Because the power switch powers the network interface but not the power module in sleep mode, the power module can be turned off in sleep mode, thereby avoiding wasting energy during idle or standby operation. Since the power rating of the industrial appliance may be one or more orders of magnitude greater than the power rating of the network interface (the latter is typically in the range of 6W to 10W), the availability of sleep mode can save significant energy.

[0010] In a second aspect of the invention, a method of operating an industrial controller having the above general characteristics is provided. In particular, the industrial controller may include a drive module for driving an industrial appliance, a network interface toward an external network, a power module for directly powering the drive module and the network interface, and a power switch connected to an input power supply. The method includes receiving an indication of whether to operate in an operating mode or a sleep mode. In response to the operating mode indication, the power switch powers the power module, and the power module powers the drive module and the network interface. Otherwise, in response to the sleep mode indication, the power switch powers the network interface instead of the power module.

[0011] The method according to the second aspect generally shares the technical effects and advantages associated with the first aspect. Further, it can be implemented with corresponding degree of technical changes.

[0012] The invention also relates to a computer program comprising instructions for causing a computer or in particular an industrial controller to perform the above method. The computer program may be stored or distributed on a data carrier. As used herein, a "data carrier" may be a transient data carrier (such as a modulated electromagnetic wave or light wave) or a non-transient data carrier. Non-transient data carriers include volatile and non-volatile memories, such as permanent storage media and non-permanent storage media of the magnetic, optical or solid-state type. Still within the scope of a "data carrier", such a memory may be fixedly mounted or portable.

[0013] In general, unless otherwise expressly defined herein, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field. Unless otherwise expressly stated, all references to "a / an / the element, device, component, mode, step, etc." are to be openly interpreted as referring to at least one instance of an element, device, component, mode, step, etc. Unless expressly stated otherwise, the steps of any method disclosed herein do not have to be performed in the exact order described. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various aspects and embodiments will now be described by way of example and with reference to the accompanying drawings, in which

[0015] Figure 1 An industrial controller arranged to drive an industrial appliance is shown; and

[0016] Figure 2 Yes Operation Figure 1 A block diagram of a method of an industrial controller of the type shown. DETAILED DESCRIPTION

[0017] Various aspects of the disclosure will now be more fully described in conjunction with the accompanying drawings, in which certain embodiments of the invention are shown. However, these aspects may be embodied in many different forms and should not be construed as limiting; rather, these embodiments are provided by way of example so that the disclosure will be thorough and complete and will fully convey the scope of the various aspects of the invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0018] Figure 1An industrial controller 100 arranged to drive an industrial appliance 10 is shown. The industrial controller 100 and the industrial appliance 10 can be arranged in an industrial facility (such as a factory or a manufacturing plant or a site). The industrial appliance 10 generally includes a plurality of actuators, such as a motor. The actuator in the industrial appliance 10 is configured to receive at least one drive signal U8 carrying control information and power. The drive signal U8 is the main energy source or the only energy source of the industrial appliance 10. For example, each drive signal U8 can be a modulated single-phase or multi-phase AC signal, which is suitable for causing the motor to apply a desired torque, move at a desired linear or angular velocity, or perform a similar desired operation. Because the drive signal U8 has different waveforms to achieve different torques and different speeds, it can be considered that it has the content of control information. Alternatively, the drive signal U8 can be composed of a power channel and a separate control information channel.

[0019] The industrial tool 10 may include processing equipment (e.g., processing, cutting, shaping, forming, vibrating, pressing, coating, heating), material handling equipment (e.g., picking, placing, flipping, packaging, conveying), and / or inspection equipment (e.g., optical imaging, X-ray imaging, mechanical, electrical, or chemical testing). In particular, the industrial tool 10 may include, for example, Figure 1 At least one industrial robot or at least one automated guided vehicle (AGV) is proposed.

[0020] The industrial controller 100 is connected to an external network 20, such as a data network or a communication network, through a network interface 106. Figure 1 As shown, the industrial controller 100 may also include an internal network adapted to transmit internal data signals between components of the industrial controller 100. The external network 20 may be a wired network or a wireless network, and it may be designed for local area communication or wide area communication.

[0021] The network interface 106 can be multifunctional. On the one hand, it can be used to remotely monitor the industrial appliance 10. The remote monitoring can be performed by a centralized safety function (or safety chain), which can be embodied as a software application implemented on a host 21 connected to the external network 20. The host 21 can be a controller other than the industrial controller 100, such as a programmable logic controller (PLC) in an industrial facility. The safety function implemented on the host 21 can be responsible for monitoring the entire industrial facility or a preconfigured portion of the industrial facility, and it can, for example, use Profinet TM or Profisafe TMProtocol. Monitoring of safety functions may include asking the industrial controller 100 (e.g., polling, sending echo messages) about the presence and / or health of predefined components. Alternatively, monitoring may use a protocol by which the industrial controller 100 (and possibly all similar units in the same facility) should send status reports to the safety functions of its own motion, for example in a periodic manner or in an event-triggered manner. In particular, monitoring may be intended to confirm the presence and operability of safety-related sensors (e.g., fire sensors, safety light curtains, emergency stop switches) and safety-related actuators (e.g., fire sprinklers, fire doors, gates). The network interface 106 may be equipped with a safety controller 106.1 (e.g., a programmable processor) that is configured to perform tasks related to such monitoring.

[0022] On the other hand, the network interface 106 can assist in remote control of the industrial tool 10. For example, the network interface 106 may be responsible for receiving high-level instructions to be implemented, confirming instructions, and / or transmitting reports on whether earlier instructions have been successfully performed. The high-level instructions may come from an operator or a control application in a superior controller, such as a task scheduler. When remotely controlling the industrial tool 10, the network interface 106 can be configured to convert the high-level instructions into machine-level instructions suitable for actuators in the industrial tool 10. The remote control can also include a network interface 106 that obtains sensor data from the industrial tool 10 and relays appropriate portions thereof to the operator or task scheduler. These tasks and other tasks can be implemented by the processing circuit system 106.2 in the network interface 106.

[0023] The industrial controller 100 is also connected to an input power source 30 through a power switch (or Wake-on-LAN module) 102. The input power source may be a power grid with a grid voltage of 400V AC or higher. Alternatively, the input power source 30 may be output from a local power conversion plant (not shown) or a battery.

[0024] The output side of the power switch 102 is connected to a power module 104 and a network interface 106. The power module 104 is connected to a drive module 108 (which is configured to drive the industrial tool 10) and the network interface 106. The power module 104 and the drive module 108 may be separate components, such as Figure 1 As shown, it can also be integrated into a single component. The drive module 108 can be equipped with suitable components, such as analog voltage converters or solid-state power electronic components, to generate the signal U8 described above. Figure 1As shown, a direct connection U7 from the power module 104 to the driver module 108 can be provided. Connection U7 is a direct connection in the sense that it does not pass through any other components between the power module 104 and the driver module 108 and / or in the sense that the driver module 108 is not embedded in any other components but directly interfaces with the power module 104. Direct connection U7 allows the power module 104 to directly power the driver module 108. In various embodiments where the input power supply 30 is an AC source and the driver module 108 is designed for AC power, the power module 104 can perform AC to DC conversion (rectification) and apply the output voltage to the DC bus. The DC bus or a portion thereof forms connection U7. The output voltage can be 400V DC, and the rated power may be at least 100W, at least 1kW, at least 10kW or even higher. Alternatively or additionally, the power module 104 can be configured to supply a suitable regulated voltage, such as 24V DC, to the network interface 106 via connection U9. Connection U9 can be implemented as (a part of) a voltage trunk bus. A typical power rating of the network interface 106 may be in the range of 6 W to 10 W. Conditioning may include down-conversion and rectification of the example voltage 24 V DC. Conditioning may also include various types of filtering (to prevent voltage spikes), stabilization (frequency, voltage) and / or temporary backup power.

[0025] The industrial controller 100 is capable of operating in an operating mode (or active mode) and a sleep mode (or energy saving mode), and may operate in other modes. The power switch 102 performs several functions related to switching between modes. This can be governed by a control signal U3 from the network interface 106 to the power switch 102. The network interface 106 can be configured to switch the control signal U3 from a value representing the sleep mode to a value representing the operating mode in response to a wake-up signal that the network interface 106 has received through the external network 20. The reverse switching of the control signal U3 from the operating mode to the sleep mode can be triggered by a similar externally received signal or by an internal process in the industrial controller 100 (such as a timeout).

[0026] In the working mode, the power switch 102 provides power to the power module 104. In the sleeping mode, the power switch 102 provides power to the network interface 106 through the power connection U2 but does not provide power to the power module 104.

[0027] Obviously, because the power module 104 receives power from the input power source 30 via the power switch 102 in the working mode, the power module 104 can directly power the drive module 108. Further, in the working mode, the power module 104 can also power the network interface 106, and actually power the network interface 106 through the connection U9. Although in some embodiments, the power module 104 is configured to have such behavior, it is foreseeable that in other embodiments, the network interface 106 should be powered by the power switch 102 in the working mode and the sleep mode. Common to all of these embodiments, the network interface 106 is supplied with appropriate drive power in the sleep mode and the working mode, so it can report the status of the industrial tool 10 in both modes via the external network 20. As mentioned above, the status may include confirmation that a predefined group of safety-related sensors and actuators are present and operating.

[0028] Moreover, in some embodiments, the power switch 102 can be configured to directly connect the power module 104 to the input power source 30 in the working mode. That is, the signal U6 arriving at the power module 104 is substantially the same as the signal U5 from the input power source 30. In other words, the power switch 102 acts as a temporary connector between the power module 104 and the input power source 30 in the working mode. In other embodiments, the power switch 102 processes the signal U5 from the input power source 30 in some suitable manner and provides the processed output to the power module 104.

[0029] In order for the power switch 102 to power the network interface 106 in the sleep mode, the power switch 102 includes components (not shown) for conditioning the signal U5 from the input power source 30 to be suitable for driving the network interface 106. The conditioning may be similar to the conditioning in the power module 104, and it may be performed by digital power electronics and / or analog components. In some embodiments, as shown in FIG. Figure 1 As shown, the network interface 106 has a separate data connection U1 and a separate power connection U2 towards the external network 20. In other embodiments, the connections U1 and U2 may be integrated and form a Power over Ethernet connection.

[0030] In one specific embodiment of the industrial controller 100, the processing circuitry 106.2 in the network interface 106 is configured to operate at a lower clock frequency in the sleep mode than in the active mode. Likewise, the execution of non-essential background processes may be suspended.

[0031] In another specific embodiment of the industrial controller 100, the power switch 102 is adapted for retrofitting. That is, the power switch 102 can (or is easily) installed on an existing industrial controller. The existing industrial controller may constitute legacy equipment. The existing industrial controller itself may be complete and operable for the task of driving the industrial tool 10; the addition of the power switch 102 enhances the functionality of the sleep mode with the above-mentioned characteristics.

[0032] Now, refer to Figure 2 Now let's look at the flowchart in the figure. Figure 1 The method 200 is described with reference to the industrial controller 100 shown. The method 200 may be performed by the network switch 106 in the industrial controller 100. Alternatively, the method 200 may be performed by transmitting suitable instructions or commands from a remote entity (such as the host computer 21) to the industrial controller 100.

[0033] In the first step 202 of the method 200, an indication is received as to whether to operate in a working mode or a sleep mode. The indication may be received by the network switch 106 from the external network 20. For security reasons, the indication transmitted via the external network 20 should preferably be expressed by a "magic number" (or "magic constant") (i.e., a pre-determined bit string that is long enough or unique enough to be unlikely to be confused with signal artifacts and / or difficult to be guessed by an attacker). Instead of receiving the indication from the external network 20 by the network switch 106, the indication may consist of user input given to a remote entity (separate from the industrial controller) implementing the method 200. Alternatively, the indication may consist of an instruction from the control application being implemented. The act of "receiving" the indication may include having the implementing entity read the current value of the indication from a memory (polling). The value of the received indication determines whether the implementation flow of the method 200 continues according to the working mode (WM, left branch) or according to the sleep mode (SM, right branch).

[0034] In response to receiving the sleep mode indication, the power switch 102 is caused 208 to power the network interface 106 but not the power module 104. The power switch 102 can be configured to galvanically isolate the power module 104 from the input power source 30 in the sleep mode. Optionally, the network interface 106 is caused 210 to operate at a lower clock frequency in the sleep mode.

[0035] In response to receiving the operating mode indication (or wake-up indication), the power switch is caused 204 to power the power module 104, and the power module 104 is caused 206 to power the driver module 108. In embodiments where the network interface 106 is operated at a lower clock frequency in the sleep mode, it resumes normal operation.

[0036] like Figure 2 As suggested by the upward subsection in , when a new mode indication is received, the implementation process is resumed from step 202, thereby repeating the subsequent conditional steps. Alternatively, the implementation process is resumed from step 202 periodically or after the latest received indication expires by retrieving the current value of the mode indication.

[0037] Steps 204 and 208 may be performed by having the network interface 106 apply appropriate values ​​of the control signal U3 to the power switch 102 .

[0038] The method 200 may include another step 212 of reporting the status of the industrial appliance 10. This step 212 is performed regardless of the operating mode or sleep mode indication. Thus, even if the industrial controller 100 is in sleep mode or it is about to switch to sleep mode in response to a received indication, the status is reported. Step 212 may include listening for incoming communications from security functions in the industrial facility, such as Profinet TM Communication or Profisafe TM communications, and respond to those communications accordingly.

[0039] As mentioned previously, it is not essential for the present invention that in the operating mode, the network interface 106 is powered via the power module 104 or directly from the power switch 102. The second option may avoid some duplication of components, particularly circuitry for providing a regulated voltage to the network interface 106. Under the first option, transitions to and from the sleep mode would include handing over the power supply of the network interface 106 from the power module 104 to the power switch 102, and vice versa.

[0040] Above, various aspects of the disclosure have been described with reference to a few embodiments. However, as readily appreciated by a person skilled in the art, other embodiments than those described above are equally possible within the scope of the invention, as defined by the appended patent claims.

Claims

1. An industrial controller (100), capable of operating in a working mode and a sleep mode, the industrial controller comprising: A driving module (108) configured to drive the industrial tool (10); a network interface (106) configured to communicate with an external network (20); as well as A power module (104) is configured to directly supply power to the driving module in the working mode. The invention is characterized by a power switch (102) connected to an input power source (30) and configured to supply power to the power module in the working mode and to supply power to the network interface but not to the power module in the sleep mode.

2. The industrial controller (100) of claim 1, wherein the network interface (106) comprises: a data connection (U1) towards said external network (20); as well as A power connection (U2), separate from the data connection, is directed toward the power switch (102).

3. The industrial controller (100) according to claim 1 or 2, wherein the power module (104) is configured to directly power the network interface (106) in the working mode.

4. The industrial controller (100) according to claim 1 or 2, wherein the power switch (102) is configured to not provide power to the network interface (106) in the operating mode.

5. The industrial controller (100) according to claim 1 or 2, wherein the power switch (102) is configured to supply power to the network interface (106) in the working mode.

6. The industrial controller (100) according to any one of the preceding claims, wherein the power switch (102) is configured to connect the power module (104) directly to the input power source (30) in the operating mode.

7. The industrial controller (100) according to any one of the preceding claims, wherein the power switch (102) is configured to selectively operate in a working mode or a sleep mode according to an instruction (U3) from the network interface (106).

8. The industrial controller (100) according to any one of the preceding claims, wherein the industrial tool (10) is an industrial robot.

9. The industrial controller (100) according to any one of the preceding claims, wherein the network interface (106) comprises a safety controller (106.1) configured to report the status of the industrial tool (10) in the working mode and the sleep mode via the external network (20).

10. The industrial controller (100) of any one of the preceding claims, wherein the network interface (106) comprises processing circuitry (106.2) configured to operate at a lower clock frequency in the sleep mode than in the operating mode.

11. The industrial controller (100) according to any one of the preceding claims, wherein the power switch (102) is adapted for retrofitting.

12. A method (200) of operating an industrial controller (100), the industrial controller (100) comprising: A driving module (108) for driving the industrial tool (10); A network interface (106) for communicating with an external network (20); A power module (104), used to directly supply power to the driving module and the network interface; as well as A power switch (102) connected to an input power source (30), The method comprises: receiving (202) an indication of whether to operate in an active mode or a sleep mode; In response to the operating mode indication, causing (204) the power switch to supply power to the power module; and enabling (206) the power module to supply power to the driving module; In response to a sleep mode indication: The power switch is caused (208) to provide power to the network interface but not to the power module.

13. The method (200) of claim 12, wherein the indication (U3) is received (202) from the network interface (106).

14. The method (200) according to claim 12 or 13, further comprising: In response to the sleep mode indication, the network interface is caused (210) to operate at a reduced clock frequency.

15. The method (200) according to any one of claims 12 to 14, further comprising: A status of the industrial tool (10) is reported (212) independent of the indication.

16. A computer program comprising instructions for causing the industrial controller according to claim 1 to perform the steps of the method according to claim 12.

Images