Input / output switching equipment

Abstract

An input / output switching device (6) is provided, comprising an Ethernet switch (3), a plurality of plug-in module slots (7) having conductive terminals (11, 12), and one or more internal buses (4a, 4b) for transferring power and data from the Ethernet switch (3) to the conductive terminals (11, 12). The Ethernet switch comprises at least one powered single pair of Ethernet backbone ports (1), at least one powered single pair of Ethernet branch ports (2) and an isolator (18) located between the at least one backbone port and the at least one branch port. An isolator (18) provides electrical isolation of power and data between a non-intrinsically safe side (18a) of the Ethernet switch having at least one powered single pair of Ethernet backbone ports (1) and an intrinsically safe side (18b) of the Ethernet switch having at least one powered single pair of Ethernet branch ports (2). The Ethernet switch (3) further comprises a power source (21) configured to power the Ethernet switch and the one or more internal buses (4a, 4b) through the at least one powered single pair of Ethernet backbone ports (1).

Description

Technical Field

[0001] This invention relates to an input / output switching device, specifically applicable to powered single-pair Ethernet networks, such as Ethernet-APL. Background Technology

[0002] Currently available powered single-pair Ethernet-APL field switches are specifically designed for connecting Ethernet-APL field devices. However, for any existing process plant (brown field) or new process plant (green field), not all instruments used for control and monitoring (including emergency stop / alarms) are Ethernet-APL compatible or can be retrofitted to be Ethernet-APL compatible. Therefore, to integrate these non-Ethernet-APL compatible devices / instruments into the control system or safety instrumented system (SIS), costly input / output (I / O) systems must be added to the existing Ethernet-APL solution.

[0003] The simplest approach is to traditionally cable separately for each non-Ethernet-APL device; however, this method is costly, bulky, and less reliable. Furthermore, separate cabling requires additional input / output systems in the control room or local equipment room. Adding complexity, some plants require intrinsically safe equipment in hazardous areas, meaning additional fencing hardware, separate cable designs, management schemes, and different maintenance methods are necessary. The increased cabling costs are due to the fact that, in most cases, non-Ethernet-APL devices (e.g., digital devices or 4-20mA devices) are loosely distributed (layered) throughout the process plant, making clustering inconvenient.

[0004] Using traditional remote I / O to solve this problem would significantly increase costs because it requires powering the system, incurs high rack and hardware costs, necessitates the deployment of repeaters (or fiber optics) for long-distance Ethernet communication, and can only connect to a limited number of localized devices, where the ratio of I / O points supported by each I / O system would be unacceptably low. Therefore, traditional remote I / O is an impractical solution due to its high cost, low speed, and overall complexity.

[0005] Traditional remote input / output solutions also employ low-speed internal digital input / output buses, such as HARTIP or RS485, which interface with high-speed Ethernet networks (e.g., PROFINET) for uplink communication. This internal bus needs to carry multiple control loops and measurements from digital and analog devices, as well as additional serial input / output data, resulting in a low communication rate. Therefore, it is impossible to operate high-speed communication devices (e.g., Ethernet-APL devices) through traditional remote input / output systems.

[0006] Furthermore, for hazardous areas, both remote input / output (ROI) and dedicated Ethernet-APL-based RPI / output require expensive, explosion-proof certified cabinets separate from the Ethernet-APL switch cabinets, or a larger, more expensive explosion-proof cabinet, which may require certification for each different application / configuration design. In short, RPI or Ethernet-APL-based RPI / output is only effective / efficient when high-density clusters of similar input / output types are placed close to each other and no Ethernet-APL devices are present in the same location. This is unlikely to occur with the widespread adoption of Ethernet-APL technology or the migration / upgrade of process plants to Ethernet-APL.

[0007] Therefore, the purpose of this invention is to improve upon the prior art. Summary of the Invention

[0008] According to a first aspect of the invention, an input / output switching device is provided, comprising an Ethernet switch, a plurality of plug-in module slots having conductive terminals, and one or more internal buses for transmitting power and data from the Ethernet switch to the conductive terminals. The Ethernet switch includes at least one powered single-pair Ethernet backbone port, at least one powered single-pair Ethernet branch port, and an isolator located between the at least one backbone port and the at least one branch port. The isolator provides electrical isolation of power and data between the non-intrinsically safe side and the intrinsically safe side of the Ethernet switch, the non-intrinsically safe side having at least one powered single-pair Ethernet backbone port, and the intrinsically safe side having at least one powered single-pair Ethernet branch port. The isolator is capable of providing capacitive isolation, magnetic isolation, and / or optical isolation, for example conforming to IEC 60079 Part 11:2023. The Ethernet branch port can be used to provide a single-pair Ethernet connection to power equipment / instruments in hazardous areas (e.g., areas such as oil drilling platforms where electrical equipment must have its power limited to avoid sparks in the event of a fault). The Ethernet branch port can also support connection to fieldbus process automation (Profibus PA) devices.

[0009] Ethernet switches also include a power supply configured to power the Ethernet switch and one or more internal buses via at least one powered single-pair Ethernet backbone port. Therefore, input / output switching devices may not require any separate power input and can be powered solely by the backbone port. The internal bus can be a live bus used to power any connected devices / instruments, so the power required by all connected devices / instruments can also be provided via the powered single-pair Ethernet backbone port, through the power supply and the internal bus.

[0010] According to a second aspect of the invention, an input / output switching system is provided, comprising an input / output switching device according to the first aspect and a plug-in module physically inserted into one of a plug-in module slot for connection to conductive terminals. The plug-in module includes one or more input / output port connectors for connecting the input / output device via a corresponding cable.

[0011] Therefore, plug-in module slots and plug-in modules allow a single pair of Ethernet backbone cables to be connected to non-Ethernet-APL devices such as HART, 4-20 mA, Foundation Fieldbus, Fieldbus, thermocouples, RTDs, strain gauges, voltage-type devices, digital inputs / outputs (switches and semiconductors), Modbus, etc.

[0012] The plug-in module slots are connected to the Ethernet switch via an internal bus, which includes, for example, a non-intrinsically safe power and data bus, and / or an intrinsically safe power and data bus. The non-intrinsically safe power and data bus connects from the non-intrinsically safe side of the Ethernet switch to the non-intrinsically safe plug-in module slots within the plug-in module slots, while the intrinsically safe power and data bus connects from the intrinsically safe side of the Ethernet switch to the intrinsically safe plug-in module slots within the plug-in module slots. Therefore, the input / output switching device can provide support for both non-intrinsically safe and intrinsically safe devices.

[0013] The intrinsically safe side of an Ethernet switch may include power limiting circuitry located between the isolator and one or more branch ports, and / or between the isolator and one or more internal buses. The power limiting circuitry may include voltage clamps and / or current limiters to limit the deliverable power, thereby meeting intrinsic safety requirements.

[0014] The internal bus can be a high-speed data bus of at least 10 Mbps or at least 100 Mbps, so that data from high-speed devices can be efficiently transmitted from the plug-in module slot to the Ethernet switch. The Ethernet switch may include a central processing unit (CPU) connected to each internal bus, and an Ethernet controller / manager for controlling the switching performed by the Ethernet switch. The CPU can be integrated with the Ethernet controller / manager.

[0015] The non-intrinsically secure and intrinsically secure sides of an Ethernet switch, as well as the isolator, can all be formed on a single circuit board of the input / output switching device to provide a compact switching device that is easy to manufacture.

[0016] The plug-in module may include a controller for receiving data from at least one input / output port connector according to a first communication protocol, and transmitting data to an Ethernet switch via conductive terminals according to a second communication protocol different from the first communication protocol. The second communication protocol corresponding to the internal bus communicating with the plug-in module may be, for example, a Serial Peripheral Interface (SPI) protocol, an Integrated Circuit Bus (I2C) protocol, a parallel communication protocol, or an Ethernet protocol.

[0017] The first communication protocol is the communication protocol used by the device, which, depending on the specific device, can be serial / parallel or analog / digital. The plug-in module can interface with various types of non-Ethernet-APL devices, including HART, 4-20 mA, Foundation Fieldbus, Fieldbus, thermocouples, RTDs, strain gauges, voltage-type devices, digital input / output (switches and semiconductors), RS485 Modbus, etc. Optionally, the plug-in module may include a wireless antenna for enabling wireless connectivity with the device.

[0018] The plug-in module's controller may include a processor configured to process data received from at least one input / output port connector before sending it to an Ethernet switch. The processor can be remotely programmed via the Ethernet switch to define how the data is processed, such as performing autonomous monitoring / logging, loop control, interlocking, or emergency functions (including shutdown in case of a failure anywhere in the system). The plug-in module's controller may be powered solely by power drawn from an internal bus connected to conductive terminals, thus the plug-in module may not require any separate power supply.

[0019] The plug-in module may include an isolator that provides electrical isolation between the conductive terminals and at least one of the input / output port connectors, allowing the input / output port connectors to be connected to equipment in hazardous areas. The plug-in module may also include power limiting circuitry connected between the conductive terminals and one or more input / output port connectors to meet intrinsic safety requirements. The power limiting circuitry may, for example, include a voltage clamp, a current limiter, or both.

[0020] Therefore, compared to implementing the same traditional functions of remote process input / output systems and Ethernet-APL switches (including one or more Ethernet-APL backbones and one or more branches compatible with Ethernet-APL 2-WISE / FISCO), fewer components are required, while process input / output variables can be sent / received at a higher rate by using a high-speed internal bus to send / receive process input / output variable data from plug-in modules.

[0021] Plug-in modules are configurable, scalable, pluggable process input / output modules conforming to input / output types, used to communicate with Ethernet switches and enabling the Ethernet switches to efficiently map process input / output variable data along with data transmitted and received by any connected Ethernet devices into each Ethernet telegram. This solution is relatively smaller and more compact, with lower production costs, and for a given system bit rate of 10 Mbps or 100 Mbps, the backbone port can provide a higher comparable bit rate density for process data transmission / reception. When connectivity to various devices / instruments is required, plug-in modules can be inserted into plug-in module slots to connect to the internal bus. Attached Figure Description

[0022] Embodiments of the present invention will be described by way of non-limiting example with reference to the accompanying drawings, wherein: Figure 1 A schematic diagram of an input / output switching system according to an embodiment of the present invention is shown; Figure 2 It shows Figure 1 Functional block diagram of an input / output switching system; Figure 3 The structure is shown Figure 1 A schematic diagram of a plug-in module for a portion of an input / output switching system; and Figures 4a to 4e It shows that it can replace Figure 3 The diagram shows a plug-in module or other plug-in modules that complement it.

[0023] The accompanying drawings are not drawn to scale, and the same or similar reference numerals indicate the same or similar features. Detailed Implementation

[0024] Figure 1 An input / output switching system according to an embodiment of the present invention is shown, comprising an input / output switching device 6. The input / output switching device 6 may include an Ethernet switch 3, a plurality of (two in this embodiment) plug-in module slots 7, and internal buses 4a and 4b connecting the Ethernet switch 3 to the plug-in module slots 7. The Ethernet switch 3 includes at least one (two in this embodiment) powered single-pair Ethernet backbone port 1, at least one (three in this embodiment) powered single-pair Ethernet branch port 17, and an isolator 18 located between the backbone port 1 and the branch port 17.

[0025] Isolator 18 separates the non-intrinsically safe side 18a of Ethernet switch 3 from the intrinsically safe side 18b, and provides electrical isolation for power and data between these two sides of the switch to achieve intrinsic safety. Isolator 18 may include capacitive isolation and / or optical isolation, for example, conforming to IEC 60079 Part 11:2023. Electrical isolation means that the intrinsically safe side of the Ethernet switch (e.g., branch port 17) will not be able to draw excessive power from the non-intrinsically safe side of the Ethernet switch (e.g., backbone port 1), so branch port 17 can be connected to device 2 in a hazardous area where electrical sparks are not permitted.

[0026] One or more Ethernet branch ports 17 can also be power-limited by power limiting circuitry 19a on the intrinsically safe side 18b. Power limiting circuitry 19a may be a current limiter and / or a voltage clamper to further ensure that the power supplied to the branch port is insufficient to generate sparks.

[0027] The Ethernet switch 3 may include a circuit board 3a on which the non-intrinsically safe side 18a and intrinsically safe side 18b of the Ethernet switch and an isolator 18 are formed.

[0028] Internal bus 4a can be an intrinsically safe power and data bus connected to the intrinsically safe side 18b of Ethernet switch 3. Optionally, internal bus 4a can be connected to a power limiting circuit 19b of the intrinsically safe side 18b of Ethernet switch. Power limiting circuit 19b can be a current limiter and / or a voltage clamper to ensure that the power supplied to the plug-in module slot 7 connected to internal bus 4a is insufficient to generate sparks. Internal bus 4b can also be a non-intrinsically safe power and data bus connected to the non-intrinsically safe side of Ethernet switch 3, thus enabling it to provide a higher level of power to the plug-in module slot 7 to which it is connected.

[0029] Ethernet switch 3 may include CPU 22 and Ethernet controller / manager 23 for controlling the switching performed by the Ethernet switch. Ethernet switch 3 also includes power supply 21, which supplies power from backbone port 1 to the Ethernet switch (including CPU 22, Ethernet controller / manager 23, and internal buses 4a and 4b). Therefore, the Ethernet switch does not require any separate power supply and can be powered solely from backbone port 1 via power supply 21.

[0030] Each plug-in module slot 7 may include one or more AC and / or DC conductive power terminals 11 for supplying power to the plug-in module from the internal bus 4a or internal bus 4b, and may include conductive data terminals 12 for transmitting data between the internal bus 4a or internal bus 4b and the plug-in module.

[0031] Although Figure 1The implementation has two internal buses 4a and 4b, one intrinsically safe and one non-intrinsically safe. However, in other implementations, one or more internal buses may be provided. These buses may all be intrinsically safe, all be non-intrinsically safe, or a mixture of intrinsically safe and non-intrinsically safe buses. Each internal bus may be connected to the conductive terminals of one or more plug-in module slots.

[0032] The intrinsically safe bus 4a can be intrinsically safe (IS) isolated by isolator 18. If power limiting circuitry 19b is configured, IS voltage clamping and / or current limiting can be optionally added. In some cases, current limiting may be impractical due to the power requirements of the plug-in modules.

[0033] Internal buses 4a and 4b can be high-speed buses capable of transmitting data at a rate of at least 10 Mbps to meet the requirements of high-speed devices / instruments connected to the system.

[0034] The input / output switching system also includes at least one removable plug-in module that is physically inserted into a plug-in module slot. Figure 1 Examples include two plug-in modules 7a and 7b, which are inserted into two plug-in module slots 7 and connected to conductive terminals 11 and 12. Various connector configurations can be used to connect and secure each plug-in module in its respective plug-in module slot, such as using snap-fit ​​and / or friction-based fixing methods.

[0035] Plug-in modules 7a and 7b may include input / output port connectors for connecting to device / meter 5b and device / meter 5a, respectively.

[0036] Figure 2 The schematic diagram illustrates the functional block diagram of the input / output switching system 6. The backbone Ethernet port 1a can be connected to the Ethernet APL backbone cable to receive power and transmit data, and the backbone Ethernet port 1b can be connected to another Ethernet APL backbone cable to connect to another switching system. The intrinsically safe branch port 17 can be connected to the Ethernet APL branch cable of the Ethernet APL device 2.

[0037] The intrinsically safe internal bus 4a can be a dedicated high-speed bus and is connected to the CPU 22 of the Ethernet switch 3. The non-intrinsically safe internal bus 4b can be an Ethernet bus and is connected to the Ethernet port of the Ethernet switch 3. The CPU 22 can implement data transmission between the protocol of the dedicated bus 4a and the Ethernet protocol. Therefore, data from devices 5a or 5b connected to the high-speed internal bus 4a or high-speed internal bus 4b can be virtually "switched" to backbone port 1 and branch port 17, as if devices 5a or 5b were one or more Ethernet APL devices.

[0038] Data from the dedicated high-speed internal bus 4a can be seamlessly mapped into Ethernet APL messages and transmitted via the Ethernet-APL backbone 1a. Data from the Ethernet bus 4b can also be seamlessly mapped into Ethernet APL messages. The dedicated and / or Ethernet internal buses 4a and 4b can communicate with plug-in modules 7a and 7b, which in turn interface with legacy process input / output and / or legacy serial data buses (e.g., RS485 Modbus). Ethernet-APL devices can connect to one or more Ethernet-APL branch ports 17, and data from these Ethernet-APL devices can be mapped into APL messages accordingly.

[0039] Figure 3 The schematic diagram shows a block diagram of the plug-in module 7a, including its connection to conductive terminals 11 and 12 of the plug-in module slot 7. The plug-in module 7a may include one or more input / output port connectors 15 with terminals 16 for connection to a cable that connects to device / instrument 5b (see [reference]). Figure 1 In some implementations, the plug-in module 7a may also include a wireless antenna 40 for wireless connection to other devices / instruments.

[0040] Plug-in module 7a may include controller 13 for receiving data from input / output port connectors and for performing protocol conversion between the protocol used by device / instrument 5b and the Ethernet protocol used by internal bus 4b. Therefore, for Ethernet switch 3, device / instrument 5b may be the same as Ethernet-APL device / instrument.

[0041] The controller 13 can process data received from the device 5b before sending it to the internal bus 4b via the conductive data terminal 12. This processing can be, for example, pre-programmed into the plug-in module 7a, and / or the controller can be programmed via the internal bus 4b to define how the controller 13 should process the data received from the device 5b. For example, the controller 13 can perform data logging and / or data analysis, or run processing software / applications.

[0042] Controller 13 may include software / firmware and non-volatile memory that can be programmed to perform emergency functions such as autonomous monitoring / recording, loop control, interlocking, or shutdown in the event of a failure at any node in the system. During normal operation, this local control feature can be remotely managed by the main control system. For example, setpoints and PID control algorithms can be remotely adjusted, enabling the plug-in module to be semi-autonomous. The control software may also, or alternatively, reside in CPU 22 and / or Ethernet controller / manager 23.

[0043] Controller 13 may include one or more high-speed analog-to-digital converters that receive signals from device 5b and digitize the signals at high bit resolution for transmission to internal bus 4b. Therefore, the rate of each internal bus should be capable of collecting high-bit resolution data sequentially from each plug-in module connected to that bus.

[0044] Plug-in module 7a may include a transmitter and / or receiver 14 conforming to the physical layer specification of input / output port connector 15 for sending and / or receiving data between device / instrument 5b and controller 13. Controller 13 is capable of adjusting the settings of transmitter and / or receiver 14 via control line 9.

[0045] The transmitter and / or receiver 14 and the controller 13 can be directly powered by the conductive power supply terminal 11. Optionally, as Figure 3 As shown, plug-in module 7a may include one or more power supplies 10 that draw power from conductive power terminals 11 and supply power to transmitter and / or receiver 14 and controller 13. Power supplies 10 may be intrinsically safe or non-intrinsically safe DC-DC or AC-DC converters capable of powering various systems on the plug-in module.

[0046] The transmitter and / or receiver 14 may include intrinsically safe voltage clamping or current limiting circuitry, for example, compliant with IEC 60079 Part 11, Version 7 and / or Part 47 and / or Part 7. Different plug-in modules inserted into the different plug-in module slots 7 can be used to electrically and physically separate the Part 7 components from the Part 11 / 47 circuitry.

[0047] Depending on the intrinsic safety requirements of devices / instruments 5a and 5b, and whether the plug-in module slot to which the plug-in module will be received is intrinsically safe, various plug-in modules can be inserted into the plug-in module slot. Depending on whether intrinsically safe bus 4a or non-intrinsically safe bus 4b is used, or both intrinsically safe bus 4a and non-intrinsically safe bus 4b are used, the plug-in module may have or require optional / different components, or different protection methods / configurations. Therefore, intrinsically safe and non-intrinsically safe devices / instruments can be connected to the input / output switching device 6 via plug-in modules. For example, Figures 4A to 4E show the configurations of various plug-in modules that meet the requirements of various devices / instruments.

[0048] The plug-in module in Figure 4A allows intrinsically safe devices / instruments to connect to the non-intrinsically safe bus 4b. Specifically, the plug-in module may include an isolator 25a and a power limiting circuit 26a disposed between the non-intrinsically safe bus 4b and the input / output port connector 15a. The isolator 25a provides electrical isolation for power and data between the input / output port connector 15a and the non-intrinsically safe bus 4b, and the power limiting circuit 26a clamps the voltage and limits the current delivered to the input / output port connector 15a, thereby making the input / output port connector 15a suitable for connecting to devices in hazardous areas. The isolator 25a also isolates the power supply of the plug-in module from the non-intrinsically safe bus 4b, so that power and communication are isolated from the non-intrinsically safe backbone port 1, thereby allowing the plug-in module and the connected devices / instruments to be isolated and balanced.

[0049] The plug-in module of Figure 4B allows intrinsically safe devices / instruments to connect to the intrinsically safe bus 4a, particularly when the intrinsically safe side 18b of the Ethernet switch lacks any power limiting circuitry 19b. Specifically, the plug-in module may include power limiting circuitry 26b positioned between the intrinsically safe bus 4a and the input / output port connector 15b. Power limiting circuitry 26b clamps the voltage and limits the current delivered to the input / output port connector 15b, thereby making the input / output port connector 15b suitable for connecting to devices in hazardous areas.

[0050] The plug-in module in Figure 4C allows intrinsically safe devices / instruments to connect to the intrinsically safe bus 4a, particularly when the power limiting circuit 19b on the intrinsically safe side 18b of the Ethernet switch lacks any current limiting circuitry and only provides voltage clamping. Specifically, the plug-in module may include a current limiting circuit 26c positioned between the intrinsically safe bus 4a and the input / output port connector 15c. The current limiting circuit 26c limits the current delivered to the input / output port connector 15c, thereby making the input / output port connector 15c suitable for connecting to devices in hazardous areas.

[0051] The plug-in module in Figure 4D allows non-intrinsically safe devices / instruments to connect to the non-intrinsically safe bus 4b, thus eliminating the need for any isolators or power limiting circuitry between the non-intrinsically safe bus 4b and the input / output port connector 15d. Therefore, the input / output port connector 15d is suitable for connecting to devices that are not subject to intrinsically safe requirements or have higher power requirements.

[0052] The plug-in module of Figure 4E allows for the connection of non-intrinsically safe devices / instruments and combinations of intrinsically safe devices / instruments to the intrinsically safe bus 4a. The plug-in module provides intrinsically safe input / output port connectors 15e and non-intrinsically safe input / output port connectors 15f. The plug-in module may include power limiting circuitry 26d positioned between the intrinsically safe bus 4a and the input / output port connector 15e, particularly in cases where the intrinsically safe side 18b of the Ethernet switch lacks any power limiting circuitry 19b. Power limiting circuitry 26d clamps the voltage and limits the current delivered to the input / output port connector 15e, thus making the input / output port connector 15e suitable for connection to devices in hazardous areas. The plug-in module may include isolator 25b to provide electrical isolation for power and data between the non-intrinsically safe input / output port connector 15f and the intrinsically safe bus 4a. Therefore, if needed, non-intrinsically safe devices / instruments can still be connected to the bus 4a via input / output port connector 15f, while intrinsically safe devices / instruments can be connected via input / output port connector 15e.

[0053] Compared to implementing the same functionality in remote process input / output systems and Ethernet-APL switches (including one or more Ethernet-APL backbones and one or more branches compatible with Ethernet-APL 2-WISE / FISCO), this approach reduces the number of components required. By using a faster internal bus (e.g., SPI, I2C, parallel, or Ethernet) to send / receive process input / output variable data between configurable, scalable, pluggable process input / output modules conforming to input / output types and the switch, this approach enables the transmission / reception of process input / output variables at higher rates. The switch can efficiently map process input / output variable data along with data transmitted and received by any connected Ethernet-APL devices into each Ethernet-APL message, resulting in a relatively smaller, more compact solution with lower production costs. For a given system bit rate of 10 Mbps or 100 Mbps, the Ethernet-APL backbone port can achieve a higher comparable bit rate density for sending / receiving process data.

[0054] Furthermore, this solution is suitable for installation in Zone 1 IIB or IIC gas groups, and its intrinsically safe input / output interfaces can be connected to instruments or equipment suitable for Zone 0 IIB or IIC gas groups, while also being optional to connect to non-intrinsically safe instruments or equipment suitable for Zone 1 IIB or IIC gas groups.

[0055] It will be apparent to those skilled in the art that many other variations of the described embodiments are within the scope of protection of this invention.

Claims

1. An input / output switching device comprising an Ethernet switch, a plurality of plug-in module slots having conductive terminals, and one or more internal buses for transmitting power and data from the Ethernet switch to the conductive terminals, wherein the Ethernet switch comprising at least one powered single-pair Ethernet trunk port, at least one powered single-pair Ethernet branch port, and an isolator between the at least one trunk port and the at least one branch port, wherein the isolator provides galvanic isolation of power and data between a non-intrinsically safe side of the Ethernet switch having the at least one powered single-pair Ethernet trunk port and an intrinsically safe side of the Ethernet switch having the at least one powered single-pair Ethernet branch port; wherein the Ethernet switch further comprises a power supply configured to power the Ethernet switch and the one or more internal buses through the at least one powered single-pair Ethernet trunk port.

2. The input / output switching device of claim 1, wherein, the intrinsically safe side of the Ethernet switch comprises a power limiting circuit for the at least one branch port, wherein the power limiting circuit is connected between the isolator and the at least one branch port, and the power limiting circuit comprises a voltage clamping device, a current limiter, or a voltage clamping device and a current limiter.

3. The input / output switching device according to claim 1 or 2, wherein, the internal buses comprise a non-intrinsically safe power and data bus connected from the non-intrinsically safe side of the Ethernet switch to non-intrinsically safe plug-in module slots of the plug-in module slots.

4. The input / output switching device of claim 1, 2, or 3, wherein, the internal buses comprise an intrinsically safe power and data bus connected from the intrinsically safe side of the Ethernet switch to intrinsically safe plug-in module slots of the plug-in module slots.

5. The input / output switching device of claim 4, wherein, the intrinsically safe side of the Ethernet switch comprises a power limiting circuit for the intrinsically safe power and data bus, wherein the power limiting circuit is connected between the isolator and the intrinsically safe power and data bus, and the power limiting circuit comprises a voltage clamping device, a current limiter, or a voltage clamping device and a current limiter.

6. The input / output switching device of any of the preceding claims, wherein, the internal buses are high speed data buses of at least 10 Mbps.

7. The input / output switching device of any of the preceding claims, wherein, the non-intrinsically safe side and the intrinsically safe side of the Ethernet switch and the isolator are all formed on a single circuit board of the input / output switching device.

8. The input / output switching device of any of the preceding claims, wherein, the Ethernet switch comprises an Ethernet controller / manager powered only by the power supply.

9. The input / output switching device of any of the preceding claims, wherein, the isolator provides capacitive isolation, magnetic isolation, and / or optical isolation, for example in compliance with IEC 60079 Part 11:2023.

10. An input / output switching system comprising an input / output switching device according to any of the preceding claims and a plug-in module physically inserted into one of the plug-in module slots to connect to the conductive terminals, the plug-in module comprising one or more input / output port connectors for connecting input / output devices via respective cable connections.

11. The input / output switching system of claim 10, wherein, The plug-in module includes a controller for receiving data from at least one of the input / output port connectors according to a first communication protocol and transmitting data to the Ethernet switch via the conductive terminal according to a second communication protocol different from the first communication protocol.

12. The input / output switching system of claim 11, wherein, The controller of the plug-in module includes a processor configured to process data received from the at least one input / output port connector prior to transmitting the data to the Ethernet switch.

13. The input / output switching system of claim 12, wherein, The processor is remotely programmable via the Ethernet switch to define how data is processed.

14. The input / output switching system of claim 11, 12 or 13, wherein, The controller of the plug-in module is powered solely by power obtained from the internal bus connected to the conductive terminal.

15. The input / output switching system of any of claims 10 to 14, wherein, The plug-in module includes an isolator providing electrical isolation between the conductive terminal and at least a first one of the input / output port connectors.

16. The input / output switching system of any of claims 10 to 15, wherein, The plug-in module includes a power limiting circuit connected between the conductive terminal and one or more of the input / output port connectors, wherein the power limiting circuit includes a voltage clamp, a current limiter, or both a voltage clamp and a current limiter.

17. The input / output switching system of claim 16, when dependent on claim 15, wherein the power limiting circuit of the plug-in module is connected between the isolator of the plug-in module and the first input / output port connector.

18. The input / output switching system of claim 14 or any claim dependent on claim 14, wherein, At least a second one of the input / output port connectors is free of any isolator between the input / output port connector and the conductive terminal.

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