Safety loop state monitoring circuit and safety control system
By using bidirectional monitoring circuits and optocoupling circuits in the safety circuit, the problem that traditional detection methods cannot monitor bidirectional signals at the same time is solved, and bidirectional detection and electrical isolation of the safety circuit are achieved, improving the safety and reliability of the system.
Patent Information
- Application Number
- CN202422268007.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-09-14
AI Technical Summary
The detection method of traditional safety circuit cannot monitor the bidirectional signal status at the same time, and emergency stop switching operation may lead to loss of equipment data and abnormal control logic. Conventional semiconductor detection modules cannot meet the electrical safety requirements of the safety circuit.
Bidirectional monitoring circuits are adopted, including forward and reverse diodes, transistors and optocoupler circuits, to realize bidirectional monitoring of safety loop signals and electrically isolate them through optocoupler circuits to ensure that they can be detected in time no matter how the signal flows.
It realizes timely detection of bidirectional signals of the safety loop, improves the anti-interference ability and security of the system, and avoids data loss and control logic abnormalities caused by emergency stop operation of the equipment.
Smart Images
Figure CN223123180U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuit technology, and particularly to a safety loop status monitoring circuit and a safety control system. Background Art
[0002] In industrial automation, control systems, or specific equipment, a safety loop is a crucial part. It is designed to monitor and prevent potential safety risks during system operation. When a problem occurs in a critical part of the system, the safety loop can quickly detect and take measures (such as shutting down the machine) to avoid accidents.
[0003] In traditional designs, the input end of the safety loop is usually directly connected to the emergency stop switch. This method is simple and direct, but it has significant drawbacks. When the emergency stop switch is pressed, the circuit will be instantly cut off, which not only causes the equipment to stop immediately, but also may lead to the loss of data being processed that has not been saved in time, and may further cause abnormal control logic of the equipment. Therefore, it is necessary to monitor the status of the safety loop. However, since the safety module in the safety loop determines whether the input end is conducting through its internal logic control circuit to judge whether the safety loop is normal, no components that can generate a large voltage drop are allowed in this safety loop. Therefore, the safety loop status monitoring scheme does not support conventional detection modules such as resistors that can generate a large voltage drop.
[0004] In addition, due to the specific current flow direction at the input end of the safety loop itself to ensure the electrical safety and logic of the equipment in the normal working state. Conventional semiconductor detection methods (such as certain sensors or detectors) are usually only designed to detect current or signals in a single direction and cannot detect the two-way safety loop simultaneously. If it is necessary to perform two-way detection on the safety loop, more advanced sensing technologies or specific circuit designs may need to be adopted, which will undoubtedly increase the detection cost. Summary of the Utility Model
[0005] In view of this, this application proposes a safety loop status monitoring circuit and a safety control system. Through simple devices, the signal status in two directions of the safety loop can be monitored simultaneously, ensuring that no matter how the signal flows, it can be detected in time. The optocoupler circuit is also used to achieve electrical isolation, improving the anti-interference ability and safety of the system.
[0006] In the first aspect, this application provides a safety loop status monitoring circuit, including at least one two-way monitoring circuit connected between the output end and the input end of the safety loop;
[0007] The two-way monitoring circuit includes a forward first diode and a reverse second diode connected in parallel;
[0008] Both ends of the first diode are connected in parallel with a first resistor and a first triode. One end of the first resistor is connected to the positive electrode of the first diode, and the other end is connected in series with the base and emitter of the first triode and returns to the negative electrode of the first diode. The collector of the first triode is connected to the light-emitting side of the first optocoupler circuit. When the safety loop signal passes through the first diode, the first triode conducts, the first optocoupler circuit conducts and emits light, and a high-level signal is output through its photosensitive side;
[0009] Both ends of the second diode are connected in parallel with a second resistor and a second triode. One end of the second resistor is connected to the positive electrode of the second diode, and the other end is connected in series with the base and emitter of the second triode and returns to the negative electrode of the second diode. The collector of the second triode is connected to the light-emitting side of the second optocoupler circuit. When the safety loop signal passes through the second diode, the second triode conducts, the second optocoupler circuit conducts and emits light, and a high-level signal is output through its photosensitive side.
[0010] As above, in this application, a circuit that can bidirectionally monitor the state of the safety loop is formed by setting diodes connected in forward and reverse between the output end and the input end of the safety loop, and cooperating with triodes and optocoupler circuits. The bidirectional monitoring circuit uses the small voltage drop generated by the diode and cooperates with the triode to complete the amplification of the current, so as to realize the detection of the safety loop with only one diode voltage drop. When the safety loop signal flows from the positive electrode to the negative electrode of the first diode, due to the unidirectional conductivity of the diode, the current will flow through the first resistor and trigger the first triode. Under the action of the base current, the first triode conducts, and its collector is connected to the light-emitting side of the first optocoupler circuit, causing the light-emitting element inside the optocoupler circuit to emit light. After the photosensitive side of the optocoupler circuit receives the optical signal, it is converted into an electrical signal and outputs a high level, indicating that the safety loop is normal in this direction. When the safety loop signal flows from the positive electrode to the negative electrode of the second diode (i.e., in the reverse direction), the second diode conducts, the current passes through the second resistor and triggers the second triode. After the second triode conducts, its collector is connected to the light-emitting side of the second optocoupler circuit, also causing the optocoupler circuit to emit light. The photosensitive side converts the optical signal into an electrical signal again and outputs a high level, indicating that the safety loop is also normal in the reverse direction. Through this application, both directions of the safety loop can be monitored simultaneously, ensuring that no matter how the signal flows, it can be detected in time. The optocoupler circuit is also used to achieve electrical isolation, improving the anti-interference ability and safety of the system.
[0011] Optionally, the first optocoupler circuit includes a first opto-coupler. The light-emitting side input end of the first opto-coupler is connected to the first power supply through a third resistor, the light-emitting side output end is connected to the collector of the first triode, the photosensitive side input end is connected to the second power supply, and the photosensitive side output end is grounded through a fourth resistor;
[0012] The photosensitive side output end of the first opto-coupler also outputs high and low level signals externally according to the conduction situation.
[0013] As described above, the present application realizes the functions of electrical isolation and signal conversion through an optocoupler. By connecting a resistor in series between the power supply and the collector of the first triode on the light-emitting side of the optocoupler, and connecting a resistor in series between the power supply and the ground on the photosensitive side, when the safety loop signal passes through the first diode and triggers the first triode to conduct, the light-emitting side of the optocoupler conducts and emits light. The photosensitive side converts the optical signal into an electrical signal and outputs a high-level signal. Thus, the conduction state of the safety loop in this direction can be judged according to the high and low level signals output by the optocoupler circuit.
[0014] Optionally, the first optocoupler circuit further includes a reverse third diode connected in parallel to the light-emitting side of the first optocoupler.
[0015] As described above, by connecting a reverse diode in parallel to the light-emitting side (light-emitting diode) of the optocoupler, the light-emitting diode can be protected from reverse voltage damage, enhancing the reliability and stability of the entire optocoupler circuit.
[0016] Optionally, the second optocoupler circuit includes a second optocoupler. The input end of the light-emitting side of the second optocoupler is connected to the third power supply through a fifth resistor, the output end of the light-emitting side is connected to the collector of the second triode, the input end of the photosensitive side is connected to the fourth power supply, and the output end of the photosensitive side is grounded through a sixth resistor;
[0017] The output end of the photosensitive side of the second optocoupler also outputs high and low level signals externally according to the conduction situation.
[0018] As described above, the present application connects a resistor in series between the power supply and the collector of the second triode on the light-emitting side of the optocoupler, and connects a resistor in series between the power supply and the ground on the photosensitive side. When the safety loop signal passes through the second diode and triggers the second triode to conduct, the light-emitting side of the optocoupler conducts and emits light. The photosensitive side converts the optical signal into an electrical signal and outputs a high-level signal. Thus, the conduction state of the safety loop in this direction can be judged according to the high and low level signals output by the optocoupler circuit.
[0019] Optionally, the second optocoupler circuit further includes a reverse fourth diode connected in parallel to the light-emitting side of the second optocoupler.
[0020] As described above, by connecting a reverse diode in parallel to the light-emitting side (light-emitting diode) of the optocoupler, the light-emitting diode can be protected from reverse voltage damage, enhancing the reliability and stability of the entire optocoupler circuit.
[0021] Optionally, it further includes a logic processing circuit for monitoring the states of two safety loops, and a two-way monitoring circuit is respectively arranged in each of the two safety loops;
[0022] The logic processing circuit includes a third PNP transistor, a fourth NPN transistor, and a fifth NPN transistor. The emitter of the third transistor is respectively connected to the photosensitive side output terminals of the two optocoupler circuits of the first bidirectional monitoring circuit, and the base is connected to the collector of the fourth transistor through a seventh resistor;
[0023] The base of the fourth transistor is respectively connected to the photosensitive side output terminals of the two optocoupler circuits of the second bidirectional monitoring circuit through an eighth resistor, and the emitter is grounded;
[0024] The base of the fifth transistor is connected to the collector of the third transistor through a ninth resistor. The collector of the fifth transistor is connected to a fifth power supply through a tenth resistor, and the emitter is grounded. The collector of the fifth transistor also outputs the logic processing signal of the logic processing circuit externally.
[0025] As described above, when there are two safety circuits, a bidirectional monitoring circuit is respectively arranged in each safety circuit. By setting a logic processing circuit to respectively receive the level signals output by the two bidirectional monitoring circuits, the monitoring of the two safety circuits is realized. The logic processing circuit receives the level signal output by the first bidirectional monitoring circuit through the third transistor, receives the level signal output by the second bidirectional monitoring circuit through the fourth transistor, outputs a logic processing signal through the fifth transistor, and connects the collector of the fourth transistor to the base of the third transistor, and connects the collector of the third transistor to the base of the fifth transistor. When the fourth transistor conducts, the third transistor conducts, thereby driving the fifth transistor to conduct, and the level signal output by the fifth transistor is pulled low. Thus, the conduction states of the two safety circuits can be judged according to the high and low level signals output by the logic processing circuit.
[0026] Optionally, it further includes a first processor module, which is configured to respectively receive the high and low level signals output by the first optocoupler circuit and the second optocoupler circuit, and judge the state of the safety circuit according to the high and low level signals.
[0027] As described above, the high and low level signals output by the first optocoupler circuit and the second optocoupler circuit are sampled through the input pins of the processor module, and the state of the entire safety circuit is determined according to the preset logic rules. When any abnormality is detected, the processor module can respond in a timely manner and further trigger corresponding alarms or take other safety measures.
[0028] Optionally, it further includes a second processor module, which is configured to receive the logic processing signal output by the logic processing circuit and judge the state of the two safety circuits according to the logic processing signal.
[0029] As described above, the logic processing signals output by the logic processing circuit are sampled through the input pins of the processor module, and the states of the two safety circuits are determined according to the preset logic rules. When any abnormality is detected, the processor module can respond in a timely manner and further trigger corresponding alarms or take other safety measures.
[0030] Optionally, it further includes an emergency stop switch, which is connected between the output end of the safety circuit and the two-way monitoring circuit and / or between the input end of the safety circuit and the two-way monitoring circuit.
[0031] As described above, by setting an emergency stop switch on one side of the output end or the input end of the safety circuit, the safety circuit can be quickly cut off through this emergency stop switch. When the emergency stop switch is set between the output end and the two-way monitoring circuit, when the emergency stop switch is activated, it will immediately cut off the signal at the output end and prevent the safety circuit from continuing to operate. When the emergency stop switch is set between the input end and the two-way monitoring circuit, when the emergency stop switch is activated, the input signal is cut off before entering the safety circuit, thereby preventing any potential dangerous operations from being executed.
[0032] In a second aspect, the present application provides a safety control system, including at least one safety circuit, and at least one of the above-mentioned safety circuit state monitoring circuits is connected between the output end and the input end of each safety circuit.
[0033] These and other aspects of the present application will be more clearly understood in the following description of the (multiple) embodiments. Description of the Drawings
[0034] Figure 1 It is a structural diagram of a safety circuit state monitoring circuit provided by an embodiment of the present application;
[0035] Figure 2 It is a circuit diagram of the first safety circuit state monitoring circuit provided by an embodiment of the present application;
[0036] Figure 3 It is a circuit diagram of a logic processing circuit provided by an embodiment of the present application;
[0037] Figure 4 It is a circuit diagram of the second safety circuit state monitoring circuit provided by an embodiment of the present application;
[0038] Figure 5 It is a structural diagram of a safety control system provided by an embodiment of the present application.
[0039] It should be understood that in the above structural schematic diagram, the sizes and shapes of the respective block diagrams are for reference only and should not constitute an exclusive interpretation of the embodiments of the present application. The relative positions and inclusion relationships between the respective block diagrams presented in the structural schematic diagram only schematically represent the structural associations between the block diagrams, rather than limiting the physical connection manners of the embodiments of the present application. Specific Embodiments
[0040] The following are embodiments provided in conjunction with the accompanying drawings to further illustrate the technical solutions provided by the present application. It should be understood that the system structures and service scenarios provided in the embodiments of the present application are mainly for illustrating possible implementation manners of the technical solutions of the present application and should not be construed as the only limitation to the technical solutions of the present application. Those of ordinary skill in the art will know that with the evolution of system structures and the emergence of new service scenarios, the technical solutions provided by the present application are equally applicable to similar technical problems.
[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. In case of inconsistency, the meaning stated in this specification or the meaning derived from the content recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.
[0042] The embodiments of the present application propose a safety loop status monitoring circuit and a safety control system, which can simultaneously monitor the signal status in two directions of the safety loop through simple devices, ensuring that no matter how the signal flows, it can be detected in time. An optocoupler circuit is also used to achieve electrical isolation, improving the anti-interference ability and safety of the system.
[0043] As Figure 1 shown, the embodiments of the present application provide a safety loop status monitoring circuit, which includes at least one bidirectional monitoring circuit 130 connected between the output terminal 110 and the input terminal 140 of the safety loop. Referring to Figure 2 shown, the bidirectional monitoring circuit 130 can implement the circuit structure through diodes, triodes, and optocoupler devices. It can use the small voltage drop generated by the diode in cooperation with the triode to complete the amplification of the current, so as to realize the detection of the safety loop with only one diode voltage drop. At the same time, by using diodes connected in forward and reverse, and cooperating with the triode and the optocoupler circuit, the status of the safety loop can be monitored bidirectionally without the need to distinguish between forward and reverse connections, solving the problem that traditional detection methods cannot achieve bidirectional simultaneous detection. An emergency stop switch 120 is also provided between the output terminal 110 of the safety loop and the bidirectional monitoring circuit 130. When the emergency stop switch 120 is activated, it will immediately cut off the signal at the output terminal 110, preventing the safety loop from continuing to operate and realizing the emergency stop control of the device.
[0044] In some embodiments, the emergency stop switch 120 may also be disposed between the bidirectional monitoring circuit 130 and the input end 140 of the safety loop. When the emergency stop switch is activated, the input signal is cut off before entering the safety loop, thereby preventing any potential dangerous operation from being executed.
[0045] The following refers to Figures 2 - 4 the illustrated embodiments to describe in detail the circuit structure and working principle of the safety loop status monitoring circuit according to the embodiments of the present application.
[0046] Figure 2 The following is a circuit diagram of the first safety loop status monitoring circuit provided by the embodiments of the present application. The safety loop includes an output end and an input end, and at least one bidirectional monitoring circuit is connected between the output end and the input end. Referring to Figure 2 the illustration, an emergency stop switch S1 is disposed between the bidirectional monitoring circuit and the input end. Through the emergency stop switch, the cut-off control of the safety loop can be realized. The bidirectional monitoring circuit includes a diode D1 (i.e., the first forward diode) and a diode D2 (i.e., the second reverse diode) connected in parallel bidirectionally. The positive electrode of the diode D1 is connected to the output end, and the negative electrode is connected to the input end through the emergency stop switch S1. The positive electrode of the diode D2 is connected to the input end through the emergency stop switch S1, and the negative electrode is connected to the output end of the safety loop. Through the bidirectionally connected diode D1 and diode D2, the current in any direction between the output end and the input end of the safety loop can be monitored.
[0047] Both ends of the diode D1 are shunted with a resistor R1 (i.e., the first resistor) and an NPN-type triode Q1 (i.e., the first triode). One end of the resistor R1 is connected to the positive electrode of the diode D1, and the other end is connected in series with the base and emitter of the triode Q1 and then returns to the negative electrode of the diode D1. The collector of the triode Q1 is connected to the light-emitting side output terminal of the optocoupler U1 (i.e., the first optocoupler). The light-emitting side input terminal of the optocoupler U1 is connected to the power supply VCC (i.e., the first power supply) through a resistor R3 (i.e., the third resistor). The light-sensitive side input terminal of the optocoupler U1 is connected to the power supply VDD (i.e., the second power supply), and the light-sensitive side output terminal is grounded through a resistor R4 (i.e., the fourth resistor). The light-sensitive side output terminal of the optocoupler U1 outputs a high or low level detection signal according to the conduction condition. When the safety loop is conducting and the signal flows from its output terminal to the input terminal, the diode D1 conducts, and the voltage between the base and emitter of the triode Q1 reaches the conduction voltage, causing the triode Q1 to conduct. The light-emitting side of the optocoupler U1 conducts, and the power supply VCC flows through the light-emitting side of the optocoupler U1 and then to the collector of the triode Q1. The light-sensitive side of the optocoupler U1 conducts, and the power supply VDD outputs a high-level detection signal 1 through the light-sensitive side output terminal of the optocoupler U1. When the safety loop is not connected or the emergency stop switch is turned off, the diode D1 does not conduct, the triode Q1 does not conduct, and then the optocoupler U1 does not conduct either. The light-sensitive side output terminal of the optocoupler U1 outputs a low-level detection signal 1.
[0048] Both ends of the diode D2 are connected in parallel with a resistor R2 (i.e., the second resistor) and an NPN-type triode Q2 (i.e., the second triode). One end of the resistor R2 is connected to the positive electrode of the diode D2, and the other end is connected in series with the base and emitter of the triode Q2 and then returns to the negative electrode of the diode D2. The collector of the triode Q2 is connected to the light-emitting side output terminal of the optocoupler U2 (i.e., the second optocoupler). The light-emitting side input terminal of the optocoupler U2 is connected to the power supply VCC (i.e., the third power supply) through a resistor R5 (i.e., the fifth resistor). The light-sensitive side input terminal of the optocoupler U2 is connected to the power supply VDD (i.e., the fourth power supply), and the light-sensitive side output terminal is grounded through a resistor R6 (i.e., the sixth resistor). The light-sensitive side output terminal of the optocoupler U2 outputs a high or low level detection signal according to the conduction situation. When the safety loop is conducting and the signal flows from its input terminal to the output terminal, the diode D2 conducts, and the voltage between the base and emitter of the triode Q2 reaches the conduction voltage, causing the triode Q2 to conduct. The light-emitting side of the optocoupler U2 conducts, and the power supply VCC flows to the collector of the triode Q2 after passing through the light-emitting side of the optocoupler U2. The light-sensitive side of the optocoupler U2 conducts, and the power supply VDD outputs a high-level detection signal 2 through the light-sensitive side output terminal of the optocoupler U2. When the safety loop is not connected or the emergency stop switch is disconnected, the diode D2 does not conduct, the triode Q2 does not conduct, and then the optocoupler U2 does not conduct either. The light-sensitive side output terminal of the optocoupler U2 outputs a low-level detection signal 2.
[0049] The power supply VCC in this embodiment can be the power supply of the safety relay module where the safety loop is located. After passing through the diode D1 or D2, the power supply VCC will flow back to the grounding terminal of the safety relay module to form a return path. The power supply VDD can be the power supply of the detection end, which is used to supply power to the optocoupler and subsequent logic processing circuits, processor modules, etc.
[0050] Based on Figure 2 The two-way monitoring circuit shown, the embodiment of the present application can effectively monitor the bidirectional flow of current in the safety loop through simple devices such as diodes and triodes. This design ensures that no matter in which direction the current flows, it can be detected. And by using the optocoupler as an electrical isolation element, it not only isolates the input and output circuits, but also converts the detected state into high and low level signals and outputs them to the subsequent processor module or logic processing circuit for subsequent logic processing or display.
[0051] In some embodiments, a reverse diode D3 is connected in parallel to the light-emitting side of the optocoupler U1. The negative electrode of the diode D3 is connected to the input terminal of the light-emitting side of the optocoupler U1, and the positive electrode is connected to the output terminal of the light-emitting side of the optocoupler U1. Similarly, a reverse diode D4 is connected in parallel to the light-emitting side of the optocoupler U2. The negative electrode of the diode D4 is connected to the input terminal of the light-emitting side of the optocoupler U2, and the positive electrode is connected to the output terminal of the light-emitting side of the optocoupler U2. By connecting a reverse diode in parallel to the light-emitting side of the optocoupler, during the normal operation of the circuit, if a reverse voltage appears across the light-emitting side (light-emitting diode) due to some reason (such as reverse connection of the power supply polarity, transient events in the circuit, etc.), the parallel-connected reverse diode will conduct, thereby providing a low-impedance path for the reverse current to limit the reverse current flowing through the light-emitting diode and prevent it from being damaged, thus enhancing the reliability and stability of the entire optocoupler circuit.
[0052] In some embodiments, when the safety relay module adopts a dual-safety-loop design, a Figure 2 bidirectional monitoring circuit as shown can be set at the output terminal and the input terminal of each safety loop to achieve synchronous monitoring of the dual-safety loops. Based on the status monitoring of the dual-safety loops, the embodiments of the present application can also sample the detection signals of the dual-safety loops through a logic processing circuit, and after logical processing, output the detection results of the dual-safety loops. As Figure 3 shown, the embodiments of the present application provide a logic processing circuit that can sample the detection signals of the bidirectional monitoring circuits set in the dual-safety loops and output the logical processing results.
[0053] Referring to Figure 3 as shown, the logic processing circuit includes a PNP-type triode Q3 (i.e., the third triode), an NPN-type triode Q4 (i.e., the fourth triode), and an NPN-type triode Q5 (i.e., the fifth triode). The emitter of the triode Q3 is respectively connected to the photosensitive sides of the two optocoupler circuits of the first bidirectional monitoring circuit for receiving detection signal 1 and detection signal 2 output by the first bidirectional monitoring circuit. The base of the triode Q3 is connected to the collector of the triode Q4 through a resistor R7 (i.e., the seventh resistor). The base of the triode Q4 is respectively connected to the photosensitive sides of the two optocoupler circuits of the second bidirectional monitoring circuit through a resistor R8 (i.e., the eighth resistor) for receiving detection signal 1 and detection signal 2 output by the second bidirectional monitoring circuit. The emitter of the triode Q4 is grounded to GND. The base of the triode Q5 is connected to the collector of the triode Q3 through a resistor R9 (i.e., the ninth resistor). The collector of the triode Q5 is connected to the power supply VDD (i.e., the fifth power supply) through a resistor R10 (i.e., the tenth resistor), and the emitter is grounded to GND. The collector of the triode Q5 also outputs the logical processing signal of the logic processing circuit.
[0054] Based onFigure 3 In the shown circuit, when the emergency stop switch is closed and the double safety loop of the safety relay module is normally conducting, the detection signal 1 and detection signal 2 output by the second two-way monitoring circuit in the second safety loop enter the base and emitter of the triode Q4 after being limited in current by the resistor R8, thereby conducting the collector and emitter of the triode Q4, and the resistor R7 is pulled down to the ground. The detection signal 1 and detection signal 2 output by the first two-way monitoring circuit in the first safety loop enter the emitter of the triode Q3. Since the triode Q3 is of PNP type, after the level of its base is pulled low, the emitter and base of the triode Q3 are conducted, thereby conducting the emitter and collector of the triode Q3, and the current enters the base of the triode Q5 through the resistor R9. At this time, the triode Q5 is conducted, and the level signal output by the power supply VDD through the resistor R10 is pulled down to the ground by the conducted triode Q5. Therefore, the logic processing circuit outputs a low-level logic processing signal. When the first safety loop is abnormally disconnected, the emitter and base of the triode Q3 will not be conducted, the triode Q5 is not conducted, and the power supply VDD outputs a high-level signal through the resistor R10, that is, the logic processing circuit outputs a high-level logic processing signal. Similarly, when the second safety loop is abnormally disconnected, the triode Q4 is not conducted, then the triode Q3 is not conducted, and the triode Q5 will not be conducted either. The power supply VDD outputs a high-level signal through the resistor R10, that is, the logic processing circuit outputs a high-level logic processing signal. Based on this, the conduction state of the double safety loop can be judged according to the logic processing signal output by the logic processing circuit.
[0055] In some embodiments, the logic processing signal output by the logic processing circuit can be sent to the backend processor module. The processor module determines the state of the double safety loop according to the preset logic rules. When any abnormality is detected, the processor module can respond in a timely manner and further trigger the corresponding alarm or take other safety measures.
[0056] Figure 4 The figure shows the circuit diagram of the second safety loop state monitoring circuit provided by the embodiment of the present application. Among them, EMO_LOOP1 and EMO_LOOP2 are respectively the double safety loops to be detected, and CMU, THF, and RSV are respectively the emergency stop switches arranged in the double safety loop. A two-way monitoring circuit is arranged for each of the double safety loops to be detected, and a logic processing circuit is also arranged to perform logic processing on the detection signals output by the two two-way monitoring circuits and output a logic processing signal.
[0057] Among them, the two-way monitoring circuit set in the safety loop EMO_LOOP1 includes two-way diodes D19 (i.e., the forward first diode) and D18 (i.e., the reverse second diode). Both ends of the diode D19 are shunted with a resistor R38 (i.e., the first resistor) and a triode Q9 (i.e., the first triode). The collector of the triode Q9 is connected to the light-emitting side output terminal of the optocoupler U9 (i.e., the first optocoupler). The light-emitting side input terminal of the optocoupler U9 is connected to the power supply VCC_EMO (i.e., the first power supply) through a resistor R33 (i.e., the third resistor). The photosensitive side input terminal of the optocoupler U9 is connected to the power supply VCC_SMU (i.e., the second power supply), and the photosensitive side output terminal is grounded through a resistor R40 (i.e., the fourth resistor). The photosensitive side output terminal of the optocoupler U9 outputs a high or low level detection signal according to the conduction situation; both ends of the diode D18 are shunted with a resistor R42 (i.e., the second resistor) and a triode Q11 (i.e., the second triode). The collector of the triode Q11 is connected to the light-emitting side output terminal of the optocoupler U10 (i.e., the second optocoupler). The light-emitting side input terminal of the optocoupler U10 is connected to the power supply VCC_EMO (i.e., the third power supply) through a resistor R41 (i.e., the fifth resistor). The photosensitive side input terminal of the optocoupler U10 is connected to the power supply VCC_SMU (i.e., the fourth power supply), and the photosensitive side output terminal is grounded through a resistor R43 (i.e., the sixth resistor). The photosensitive side output terminal of the optocoupler U10 outputs a high or low level detection signal according to the conduction situation.
[0058] The bidirectional monitoring circuit provided in the safety loop EMO_LOOP2 includes bidirectional diodes D20 (i.e., the first forward diode) and D21 (i.e., the second reverse diode). Both ends of the diode D20 are shunted with a resistor R30 (i.e., the first resistor) and a triode Q12 (i.e., the first triode). The collector of the triode Q12 is connected to the light-emitting side output terminal of an optocoupler U7 (i.e., the first optocoupler). The light-emitting side input terminal of the optocoupler U7 is connected to a power supply VCC_EMO (i.e., the first power supply) through a resistor R27 (i.e., the third resistor). The light-receiving side input terminal of the optocoupler U7 is connected to a power supply VCC_SMU (i.e., the second power supply), and the light-receiving side output terminal is grounded through a resistor R29 (i.e., the fourth resistor). The light-receiving side output terminal of the optocoupler U7 outputs a detection signal of high or low level to the outside according to the conduction condition; both ends of the diode D21 are shunted with a resistor R32 (i.e., the second resistor) and a triode Q6 (i.e., the second triode). The collector of the triode Q6 is connected to the light-emitting side output terminal of an optocoupler U8 (i.e., the second optocoupler). The light-emitting side input terminal of the optocoupler U8 is connected to a power supply VCC_EMO (i.e., the third power supply) through a resistor R28 (i.e., the fifth resistor). The light-receiving side input terminal of the optocoupler U8 is connected to a power supply VCC_SMU (i.e., the fourth power supply), and the light-receiving side output terminal is grounded through a resistor R31 (i.e., the sixth resistor). The light-receiving side output terminal of the optocoupler U8 outputs a detection signal of high or low level to the outside according to the conduction condition.
[0059] The logic control circuit in this embodiment includes a triode Q7 (i.e., the third triode), a triode Q8 (i.e., the fourth triode), and a triode Q10 (i.e., the fifth triode). The emitter of the triode Q7 is respectively connected to the light-receiving side output terminals of the optocoupler U7 and the optocoupler U8, and is used to receive the detection signals output by the optocoupler U7 and the optocoupler U8 respectively. The base of the triode Q7 is connected to the collector of the triode Q8 through a resistor R35 (i.e., the seventh resistor). The base of the triode Q8 is respectively connected to the light-receiving side output terminals of the optocoupler U9 and the optocoupler U10 through a resistor R36 (i.e., the eighth resistor), and is used to receive the detection signals output by the optocoupler U9 and the optocoupler U10 respectively. The emitter of the triode Q8 is grounded. The base of the triode Q10 is connected to the collector of the triode Q7 through a resistor R37 (i.e., the ninth resistor). The collector of the triode Q10 is connected to a power supply VCC_SMU (i.e., the fifth power supply) through a resistor R34 (i.e., the tenth resistor), and the emitter is grounded. The collector of the triode Q10 also outputs a logic processing signal BP_EMO_OC of this logic processing circuit to the outside.
[0060] Based on Figure 4For the circuit shown, assume the voltage of EMO_LOOP1_DET_IN is V1 and the voltage of EMO_LOOP1_DET_RTN is V2. Then:
[0061] When diode D19 conducts, V1 > V2, transistor Q9 conducts, the light-emitting diode in optocoupler U9 conducts, its photosensitive side outputs a high-level signal, and transistor Q8 conducts; when diode D18 conducts, V2 > V1, transistor Q11 conducts, the light-emitting diode in optocoupler U10 conducts, its photosensitive side outputs a high-level signal, and transistor Q8 conducts. Therefore, when the safety loop EMO_LOOP1 conducts in any direction, transistor Q8 conducts.
[0062] Based on Figure 4 For the circuit shown, assume the voltage of EMO_LOOP2_DET_IN is V3 and the voltage of EMO_LOOP2_DET_RTN is V4. Then:
[0063] When diode D20 conducts, V3 > V4, transistor Q12 conducts, the light-emitting diode in optocoupler U7 conducts, its photosensitive side outputs a high-level signal, and on the premise that transistor Q8 conducts, transistor Q7 conducts; when diode D21 conducts, V4 > V3, transistor Q6 conducts, the light-emitting diode in optocoupler U8 conducts, its photosensitive side outputs a high-level signal, and on the premise that transistor Q8 conducts, transistor Q7 conducts. Therefore, when the safety loop EMO_LOOP1 conducts, when the safety loop EMO_LOOP2 conducts in any direction, transistor Q7 conducts.
[0064] In summary, when the safety loop EMO_LOOP1 and the safety loop EMO_LOOP2 are simultaneously conducting in any direction, the triode Q8 conducts, the triode Q7 conducts, then the triode Q10 conducts, and the level at BP_EMO_OC is pulled low. That is, when the safety loop EMO_LOOP1 and the safety loop EMO_LOOP2 are both normally at a high level, the level at BP_EMO_OC is at a low level. When the safety loop EMO_LOOP1 is abnormal and at a low level, the triode Q8 does not conduct, then the triode Q7 does not conduct, the triode Q10 does not conduct, and the level at BP_EMO_OC is pulled high. That is, when the safety loop EMO_LOOP1 is abnormally at a low level, even if the safety loop EMO_LOOP2 is normally at a high level, the level at BP_EMO_OC still outputs a high level. When the safety loop EMO_LOOP2 is abnormal and at a low level, even if the triode Q8 conducts, the triode Q7 still does not conduct, then the triode Q10 does not conduct, and the level at BP_EMO_OC is pulled high. That is, when the safety loop EMO_LOOP2 is abnormally at a low level, even if the safety loop EMO_LOOP1 is normally at a high level, the level at BP_EMO_OC still outputs a high level. Therefore, through the high and low level signals output at BP_EMO_OC in this embodiment, the conduction state of the dual safety loop can be judged.
[0065] In summary, the safety loop state monitoring circuit provided by the embodiment of the present application sets diodes with reverse and forward connections between the output end and the input end of the safety loop, and cooperates with a triode and an optocoupler circuit to form a circuit capable of bidirectionally monitoring the state of the safety loop. This bidirectional monitoring circuit uses the small voltage drop generated by the diode to cooperate with the triode to complete the amplification of the current, so as to realize the detection of the safety loop with only the voltage drop of one diode. The embodiment of the present application solves the problems of equipment data loss and control logic abnormality caused by the operation of the emergency stop switch in the traditional design, and overcomes the limitations of the conventional semiconductor detection method in the detection of the bidirectional safety loop. And by strengthening the state monitoring of the safety relay and optimizing the circuit design, more accurate and reliable monitoring of the safety loop can be achieved, thereby improving the overall performance and safety of the equipment.
[0066] As Figure 5 shown, the embodiment of the present application provides a safety control system, including at least one safety loop 210;
[0067] Among them, at least one safety loop state monitoring circuit 220 is connected between the output end and the input end of each safety loop 210 for bidirectionally monitoring the state of the safety loop.
[0068] It should be understood that the processing details of the safety loop state monitoring circuit in the embodiment of the present application can be referred to Figures 1 - 4Regarding the related descriptions of the illustrated embodiments and related extended embodiments, the embodiments of the present application will not be repeated.
[0069] It should be noted that the embodiments described in the present application are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application usually described and illustrated in the drawings can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but only represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.
[0070] The terms "first, second, third, etc." or similar terms such as module A, module B, module C, etc. in the specification and claims are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that, where permitted, the specific order or sequence can be interchanged so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.
[0071] In the above description, the reference numerals representing steps do not necessarily mean that the steps will be executed in this order. It may also include intermediate steps or be replaced by other steps. Where permitted, the order of the front and back steps can be interchanged, or they can be executed simultaneously.
[0072] The term "comprising" used in the specification and claims should not be construed as being limited to the content listed thereafter; it does not exclude other elements or steps. Therefore, it should be construed as specifying the presence of the stated features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps or components and their groups. Therefore, the expression "a device comprising device A and B" should not be limited to a device consisting only of components A and B.
[0073] The "one embodiment" or "embodiment" mentioned in this specification means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Therefore, the phrases "in one embodiment" or "in an embodiment" that appear throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. In addition, in various embodiments of the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.
[0074] Note that the above is only a preferred embodiment of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, more other equivalent embodiments can be included, all of which fall within the protection scope of the present application.
Claims
1. A safety loop status monitoring circuit, characterized in that, It includes at least one two-way monitoring circuit connected between the output end and the input end of the safety circuit; The two-way monitoring circuit includes a forward first diode and a reverse second diode connected in parallel; Both ends of the first diode are connected in parallel with a first resistor and a first triode. One end of the first resistor is connected to the positive electrode of the first diode, and the other end is connected in series with the base and emitter of the first triode and then returns to the negative electrode of the first diode. The collector of the first triode is connected to the light-emitting side of the first optocoupler circuit. When the safety circuit signal passes through the first diode, the first triode conducts, the first optocoupler circuit conducts and emits light, and a high-level signal is output through its photosensitive side; Both ends of the second diode are connected in parallel with a second resistor and a second triode. One end of the second resistor is connected to the positive electrode of the second diode, and the other end is connected in series with the base and emitter of the second triode and then returns to the negative electrode of the second diode. The collector of the second triode is connected to the light-emitting side of the second optocoupler circuit. When the safety circuit signal passes through the second diode, the second triode conducts, the second optocoupler circuit conducts and emits light, and a high-level signal is output through its photosensitive side.
2. The circuit according to claim 1, wherein The first optocoupler circuit includes a first optocoupler. The light-emitting side input end of the first optocoupler is connected to the first power supply through a third resistor, the light-emitting side output end is connected to the collector of the first triode, the photosensitive side input end is connected to the second power supply, and the photosensitive side output end is grounded through a fourth resistor; The photosensitive side output end of the first optocoupler also outputs high and low level signals externally according to the conduction situation.
3. The circuit according to claim 2, wherein The first optocoupler circuit further includes a reverse third diode connected in parallel to the light-emitting side of the first optocoupler.
4. The circuit according to claim 1, wherein The second optocoupler circuit includes a second optocoupler. The light-emitting side input end of the second optocoupler is connected to the third power supply through a fifth resistor, the light-emitting side output end is connected to the collector of the second triode, the photosensitive side input end is connected to the fourth power supply, and the photosensitive side output end is grounded through a sixth resistor; The photosensitive side output end of the second optocoupler also outputs high and low level signals externally according to the conduction situation.
5. The circuit according to claim 4, wherein The second optocoupler circuit further includes a reverse fourth diode connected in parallel to the light-emitting side of the second optocoupler.
6. The circuit according to claim 1, wherein It further includes a logic processing circuit for monitoring the states of two safety circuits, and one two-way monitoring circuit is respectively arranged in the two safety circuits; The logic processing circuit includes a PNP-type third triode, an NPN-type fourth triode, and an NPN-type fifth triode. The emitter of the third triode is respectively connected to the photosensitive side output ends of the two optocoupler circuits of the first two-way monitoring circuit, and the base is connected to the collector of the fourth triode through a seventh resistor; The base of the fourth triode is respectively connected to the photosensitive side output ends of the two optocoupler circuits of the second two-way monitoring circuit through an eighth resistor, and the emitter is grounded; The base of the fifth triode is connected to the collector of the third triode through a ninth resistor. The collector of the fifth triode is connected to the fifth power supply through a tenth resistor, and the emitter is grounded. The collector of the fifth triode also outputs the logic processing signal of the logic processing circuit externally.
7. The circuit according to claim 1, wherein It further includes a first processor module, configured to respectively receive the high and low level signals output by the first optocoupler circuit and the second optocoupler circuit, and determine the state of the safety loop according to the high and low level signals.
8. The circuit according to claim 6, characterized in that, It further includes a second processor module, configured to receive the logic processing signal output by the logic processing circuit, and determine the states of two safety loops according to the logic processing signal.
9. The circuit according to claim 1, wherein It further includes an emergency stop switch, which is connected between the output end of the safety loop and the bidirectional monitoring circuit and / or between the input end of the safety loop and the bidirectional monitoring circuit.
10. A safety control system, characterized in that, It includes at least one safety loop, and at least one safety loop state monitoring circuit as described in any one of claims 1 to 9 is connected between the output end and the input end of each safety loop.