Signal isolation system and signal isolation circuit

Abstract

A signal isolation system and a signal isolation circuit, the system comprising an external device; and a signal isolation circuit coupled to the external device, comprising a control circuit for operating the signal isolation circuit in an input mode or an output mode according to a state of the external device; a digital input / output circuit for inputting / outputting signals according to the input mode or the output mode determined by the control circuit; and an input / output port coupled to the digital input / output circuit, serving as an input port or an output port according to the input mode or the output mode determined by the control circuit.

Description

Technical Field

[0001] The present invention relates to a signal isolation system and a signal isolation circuit, and in particular to a signal isolation system and a signal isolation circuit using a single port as an input port or an output port. Background Art

[0002] Digital input / output (DI / O) interfaces are widely used in industrial signal transmission. In the above application environment, there are common mode voltages, high transient voltages and electronic noise. The existing signal isolation (Signal Isolation) technology uses optocouplers to block high voltages and voltage transients, thereby stabilizing the signal transmission quality in the application environment to prevent voltage transients in the circuit from affecting other parts of the circuit, and protecting the equipment and the personnel using the equipment. Due to the increasing demand for digital input and output in the existing industrial control field, such as isolation protection, wide voltage application, support for dry contact and wet contact, the relevant industrial equipment needs to provide more input and output pins to achieve the above functions. However, after the existing industrial equipment adds the isolation protection function, it must cooperate with the hardware circuit to achieve the digital input and output function, that is, the existing hardware circuit is limited by its input port or output port can only be used as a single input or output. Therefore, the existing technology needs to be improved. Summary of the invention

[0003] Therefore, the present invention provides a signal isolation system and a signal isolation circuit, which use a single port as a digital input / output interface of an input port or an output port, so that related industrial equipment is not limited by the limitations of existing hardware on input or output interfaces.

[0004] An embodiment of the present invention discloses a signal isolation system, comprising an external device; and a signal isolation circuit coupled to the external device, comprising a control circuit for operating the signal isolation circuit in an input mode or an output mode according to a state of the external device; a digital input / output circuit for inputting / outputting signals according to the input mode or the output mode determined by the control circuit; and an input / output port coupled to the digital input / output circuit, and serving as an input port or an output port according to the input mode or the output mode determined by the control circuit.

[0005] An embodiment of the present invention further discloses a signal isolation circuit, comprising a control circuit for operating the signal isolation circuit in an input mode or an output mode according to a state of an external device; a digital input / output circuit for inputting / outputting signals according to the input mode or the output mode determined by the control circuit; and an input / output port coupled to the digital input / output circuit for serving as an input port or an output port according to the input mode or the output mode determined by the control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of a signal isolation system according to an embodiment of the present invention;

[0007] Figure 2 is a schematic diagram of a signal isolation circuit according to an embodiment of the present invention;

[0008] Figure 3 It is a schematic diagram of a signal isolation circuit according to an embodiment of the present invention being applied to a battery hybrid uninterruptible power supply system.

[0009] [Explanation of symbols]

[0010] 10: Signal isolation system

[0011] 102: External device

[0012] 104: Signal isolation circuit

[0013] 1042: Control circuit

[0014] 1044: Digital Input / Output Circuit

[0015] 1046: Input / output port

[0016] 24VDC: Signal

[0017] Auto: Automatic mode pin

[0018] DI_control: digital input control signal

[0019] DI_signal: digital input signal

[0020] DO_control: digital output control signal

[0021] DO_signal: digital output signal

[0022] GND: Ground potential

[0023] I2C: Between Integrated Circuits

[0024] I1, O1: first endpoint

[0025] I2, O2: Second endpoint

[0026] Manual: Manual mode pin

[0027] OPT_I: Input optocoupler

[0028] OPT_O: Output optocoupler

[0029] PSU: Power Supply Unit

[0030] BAT: Battery

[0031] R: Current limiting resistor

[0032] RELAY: Relay

[0033] R1, R2, R3, VPSU: contacts

[0034] SMBus: System Management Bus

[0035] SW_I1, SW_I2: Input switches

[0036] SW_O1, SW_O2: Output switch

[0037] SW: Switch

[0038] VCC: primary power supply

[0039] VDD: Secondary side power supply DETAILED DESCRIPTION

[0040] Please refer to Figure 1 , Figure 11 is a schematic diagram of a signal isolation system 10 according to an embodiment of the present invention. The signal isolation system 10 includes an external device 102 and a signal isolation circuit 104. The external device 102 is, for example, a power supply device. The signal isolation circuit 104 is coupled to the external device 102, and includes a control circuit 1042, a digital input / output circuit 1044, and an input / output port 1046. The control circuit 1042 is used to operate the signal isolation circuit 104 in an input mode or an output mode according to a state of the external device 102. The digital input / output circuit 1044 is used to input / output signals according to the input mode or output mode determined by the control circuit 1042. The input / output port 1046 is coupled to the digital input / output circuit 1044, and is used to serve as an input port or an output port according to the input mode or output mode determined by the control circuit 1042. For example, when the signal isolation circuit 104 is applied to an industrial device, the signal isolation circuit 104 can operate in an input mode according to the state of the external device 102, so as to isolate the wide voltage signal from the external device 102 through the digital input / output circuit 1044, and use the input / output port 1046 as an input port to transmit the input signal from the external device 102 to the control circuit 1042. In this way, the signal isolation system 10 of the embodiment of the present invention can achieve the purpose of input / output signal with a single port, and provide a wide range of signal control in wide voltage applications.

[0041] For details, please refer to Figure 2 , Figure 2 FIG. 1 is a schematic diagram of the signal isolation circuit 104. Figure 2 As shown, the digital input / output circuit 1044 of the signal isolation circuit 104 includes an input photocoupler OPT_I, an output photocoupler OPT_O, a plurality of input switches SW_I1, SW_I2, a plurality of output switches SW_O1, SW_O2 and a plurality of current limiting resistors R. The input photocoupler OPT_I includes a first terminal I1 and a second terminal I2, wherein the first terminal I1 is coupled to the input switch SW_I1 and the input switch SW_I2, and is coupled to a primary-side power supply VCC through the input switch SW_I1, and the second terminal I2 is coupled to the control circuit 1042 and a secondary-side power supply VDD, so that when the control circuit 1042 operates the signal isolation circuit 104 in the input mode, the control circuit 1042 turns on the input switches SW_I1, SW_I2 with a digital input control signal DI_control, so as to input a digital input signal DI_signal to the control circuit 1042.

[0042] On the other hand, the output photocoupler OPT_O is coupled to the control circuit 1042 and the output switches SW_O1 and SW_O2. The output photocoupler OPT_O includes a first terminal O1 and a second terminal O2, wherein the first terminal O1 is coupled to the output switches SW_O1 and SW_O2, and is coupled to a primary-side power supply VCC through the output switch SW_O1, and the second terminal O2 is coupled to the control circuit 1042 and a secondary-side power supply VDD, so that when the control circuit 1042 operates the signal isolation circuit 104 in the output mode, the control circuit 1042 turns on the output switches SW_O1 and SW_O2 with the digital output control signal DO_control to output a digital output signal DO_signal to the external device 102.

[0043] It is worth noting that the above-mentioned input photocoupler OPT_I and output photocoupler OPT_O are used to implement signal isolation technology, and the current limiting resistor R is used to prevent the input photocoupler OPT_I and the output photocoupler OPT_O from being burned out due to excessive current, and the input switches SW_I1, SW_I2 and the output switches SW_O1, SW_O2 can be a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), so that when the input switches SW_I1, SW_I2 or the output switches SW_O1, SW_O2 are turned on, the digital input signal DI_signal is input to the control circuit 1042 or the digital output signal DO_signal is output to the external device 102.

[0044] In addition, the signal isolation circuit 104 further includes a manual mode pin Manual and an automatic mode pin Auto. The manual mode pin Manual is coupled to the external device 102, and is used to receive a status signal about the external device 102, and transmit it to the control circuit 1042 to determine whether the signal isolation circuit 104 is operated in the input mode or the output mode. The automatic mode pin Auto is coupled to the external device 102, and is used to confirm the status signal from the external device 102 through a serial communication bus (Serial Communication BUS) to determine whether the signal isolation circuit 104 is operated in the input mode or the output mode. In other words, the control circuit 1042 of the signal isolation circuit 104 can determine whether the signal isolation circuit 104 is operated in the input mode or the output mode according to the signal received by the automatic mode pin Auto. Therefore, the signal isolation circuit 104 of the embodiment of the present invention can first define different signals as general-purpose input (GPI) signals or general-purpose output (GPO) signals. When the manual mode pin Manual receives a signal, the control circuit 1042 determines whether the signal isolation circuit 104 is operated in the input mode or the output mode. Alternatively, in another embodiment, the signal isolation circuit 104 of the embodiment of the present invention can confirm that the signal from the external device 102 is a general-purpose input signal or a general-purpose output signal through the serial communication bus of the automatic mode pin Auto, and operate the signal isolation circuit 104 in the input mode or the output mode accordingly. In this way, the signal isolation circuit 104 of the embodiment of the present invention can input / output signals through a single port to achieve the purpose of protecting the device and support the application of a dry contact and a wet contact.

[0045] According to different methods and applications, the signal isolation circuit 104 of the present invention can be applied to different devices. Figure 3 , Figure 3 1 is a schematic diagram of a signal isolation circuit 104 of an embodiment of the present invention applied to a battery hybrid uninterruptible power supply system 30. Since the battery hybrid uninterruptible power supply system 30 is a system including the signal isolation circuit 104, the component symbols of the signal isolation circuit 104 are used. In addition, the battery hybrid uninterruptible power supply system 30 further includes a relay RELAY, a switch SW and a battery BAT and is coupled to a power supply device PSU (i.e. Figure 1The external device 102 in the embodiment of the present invention is a relay RELAY, wherein the relay RELAY comprises a plurality of contacts R1, R2, and R3. The power supply device PSU is coupled to a mains voltage (e.g., 110V to 240V AC) to convert the received mains into electrical energy, so as to output the electrical energy to the battery hybrid uninterruptible power supply system 30 via a contact VPSU.

[0046] Since an Inter-Integrated Circuit Bus (I2C) or a System Management Bus (SMBus) pin of the power supply device PSU is coupled to the automatic mode pin Auto of the signal isolation circuit 104, the control circuit 1042 can confirm the status signal from the power supply device PSU through the serial communication bus to determine whether to operate the signal isolation circuit 104 in the input mode or the output mode. Therefore, when the power supply device PSU receives the mains voltage, the status signal of the power supply device PSU can be transmitted to the control circuit 1042 via a serial communication signal. Then, after receiving the status signal, the control circuit 1042 turns on the input switches SW_I1 and SW_I2, so that the signal generated by the relay RELAY is transmitted to the control circuit 1042 through the input switch SW_I2 and the input photocoupler OPT_I, so that the control circuit 1042 knows that the current mains voltage is normal. It is worth noting that when the power supply device PSU receives the AC voltage, the contacts R2 and R3 of the relay RELAY are turned on. Therefore, the power of the battery hybrid UPS 30 is provided by the power supply device PSU instead of the battery BAT.

[0047] When the mains power is not supplied normally, the power supply device PSU cannot supply power and cannot transmit the current status to the control circuit 1042. In one example, the battery BAT can leak through a body diode inside the switch SW to provide a signal 24VDC. When the control circuit 1042 receives the signal 24VDC through the manual pin Manual, it knows that the mains power is unstable, and accordingly changes the input state of the signal isolation circuit 104 to the output state, and turns on the output switches SW_O1 and SW_O2 to output a digital output signal to the switch SW through the output photocoupler OPT_O and the output switch SW_O2, and turns on the switch SW, so that the battery BAT can supply power to the control circuit 1042 for normal operation. It is worth noting that when the power supply device PSU does not receive the mains voltage (i.e., when the power supply device PSU is not supplying power normally), the contacts R1 and R3 of the relay RELAY are turned on, so the power of the battery hybrid uninterruptible power supply system 30 is provided by the battery BAT.

[0048] The above embodiments illustrate that the signal isolation circuit of the present invention can be a digital input / output interface with a single port as an input port or an output port, so that the related industrial equipment is not limited by the input or output limitations of the existing hardware pin limitations, and is suitable for providing a wider range of signal control when applied in wide voltage. In addition, users can define input and output requirements by themselves, and define input and output ports through a programmable application interface, which is not limited by the original hardware circuit, and reduces the overall circuit area and development costs. In addition, those with ordinary knowledge in this field can appropriately design signal isolation circuits according to different system requirements. For example, the switch of the digital input / output circuit can be implemented by other circuit elements, all of which are applicable to the present invention, and are not limited thereto.

[0049] In summary, the embodiments of the present invention provide a signal isolation system and a signal isolation circuit, which use a single port as a digital input / output interface of an input port or an output port, so that related industrial equipment is not limited by the input or output limitations of the existing hardware pin limitations, thereby reducing the overall circuit area and reducing development costs.

[0050] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the claims of the present invention should fall within the scope of the present invention.

Claims

1. A signal isolation system, characterized in that: Contains: an external device; and A signal isolation circuit, coupled to the external device, comprises: a control circuit for operating the signal isolation circuit in an input mode or an output mode according to a state of the external device; a digital input / output circuit, used to input / output signals according to the input mode or the output mode determined by the control circuit, wherein the digital input / output circuit comprises an input photocoupler and an output photocoupler, the control circuit is coupled to the input photocoupler and a plurality of input switches, the input photocoupler is used to input a digital input signal generated by the external device into the control circuit, and the output photocoupler is used to output a digital output signal to the external device, so that when the control circuit operates the signal isolation circuit in the input mode, the control circuit turns on the plurality of input switches; as well as An input / output port is coupled to the digital input / output circuit and serves as an input port or an output port according to the input mode or the output mode determined by the control circuit.

2. The signal isolation system according to claim 1, characterized in that: The control circuit is coupled to the output photocoupler and a plurality of output switches. The output photocoupler is coupled to the plurality of output switches so that when the control circuit operates the signal isolation circuit in the output mode, the control circuit turns on the plurality of output switches.

3. The signal isolation system according to claim 2, characterized in that: The plurality of input switches and the plurality of output switches are metal oxide semiconductor field effect transistors.

4. The signal isolation system according to claim 1, characterized in that: The signal isolation circuit further comprises: a manual mode pin coupled to the external device, for receiving a status signal of the external device and transmitting the status signal to the control circuit, so that the control circuit determines whether the signal isolation circuit operates in the input mode or the output mode; and An automatic mode pin is coupled to the external device and is used to confirm the status signal from the external device through a serial communication bus so that the control circuit determines whether the signal isolation circuit operates in the input mode or the output mode.

5. A signal isolation circuit, characterized in that: Contains: a control circuit for operating the signal isolation circuit in an input mode or an output mode according to a state of an external device; a digital input / output circuit, used to input / output a signal according to the input mode or the output mode determined by the control circuit, wherein the digital input / output circuit comprises an input photocoupler and an output photocoupler, the control circuit is coupled to the input photocoupler, the output photocoupler, a first input switch and a second input switch, the input photocoupler is used to input a digital input signal generated by the external device into the control circuit, and the output photocoupler is used to output a digital output signal to the external device, so that when the control circuit operates the signal isolation circuit in the input mode, the control circuit turns on the first input switch and the second input switch; as well as An input / output port is coupled to the digital input / output circuit and serves as an input port or an output port according to the input mode or the output mode determined by the control circuit.

6. The signal isolation circuit according to claim 5, characterized in that: The input photocoupler includes a first terminal and a second terminal, wherein the first terminal is coupled to the first input switch and the second input switch and coupled to a primary side power supply through the first input switch, and the second terminal is coupled to the control circuit and a secondary side power supply.

7. The signal isolation circuit according to claim 6, characterized in that: The first input switch and the second input switch are metal oxide semiconductor field effect transistors.

8. The signal isolation circuit according to claim 5, characterized in that: The output photocoupler includes a first terminal and a second terminal, wherein the first terminal is coupled to a first output switch and a second output switch, and is coupled to a primary-side power supply through the first output switch, and the second terminal is coupled to the control circuit and a secondary-side power supply, so that when the control circuit operates the signal isolation circuit in the output mode, the control circuit turns on the first output switch and the second output switch.

9. The signal isolation circuit according to claim 8, characterized in that: The first output switch and the second output switch are metal oxide semiconductor field effect transistors.

10. The signal isolation circuit according to claim 5, characterized in that: The signal isolation circuit further comprises: a manual mode pin coupled to the external device, for receiving a status signal of the external device and transmitting the status signal to the control circuit, so that the control circuit determines whether the signal isolation circuit operates in the input mode or the output mode; and An automatic mode pin is coupled to the external device and is used to confirm the status signal from the external device through a serial communication bus so that the control circuit determines whether the signal isolation circuit operates in the input mode or the output mode.

Images