A digital input device compatible with source type and sink type

Abstract

The present application relates to a digital input device compatible with both source and drain types, comprising: a signal processing module, a processor module, and a line break detection module; the input end of the signal processing module is connected to the signal input end, and the output end is connected to the input end of the processor module; the input end of the processor module is connected to the output end of the signal processing module and the output end of the line break detection module, and the output end is connected to the signal output end; the input end of the line break detection module is connected to the signal input end; the signal processing module and the line break detection module simultaneously receive a digital signal input from the signal input end, and respectively determine the level type of the digital signal through an operational amplifier and an optical coupler, and the processor module determines whether the digital signal belongs to a source input or a drain input based on the level type. The present application is compatible with both source and drain types, and can be connected to both source and drain devices.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to a digital input device that is compatible with source and sink types. Background Art

[0002] In the field of PLC applications, the external devices of digital input modules are generally source devices and sink devices. Generally, digital input modules on the market can only connect to source devices or sink devices. Summary of the Invention

[0003] Based on this, it is necessary to provide a digital input device that is compatible with both source and sink types to address the above technical issues. The device is compatible with both source and sink types and can be connected to both source and sink devices.

[0004] A digital input device compatible with source type and sink type, comprising: a signal processing module, a processor module and a disconnection detection module;

[0005] The input end of the signal processing module is connected to the signal input end, and the output end is connected to the input end of the processor module;

[0006] The input end of the processor module is connected to the output end of the signal processing module and the output end of the disconnection detection module, and the output end is connected to the signal output end;

[0007] The input end of the disconnection detection module is connected to the signal input end;

[0008] The signal processing module and the disconnection detection module simultaneously receive the digital signal input from the signal input end, and respectively determine the level type of the digital signal through the operational amplifier and the optocoupler. The processor module determines whether the digital signal belongs to source input or sink input according to the level type.

[0009] In one embodiment, the further comprising: a control module;

[0010] The input end of the control module is connected to the output end of the processor module, and the output end is connected to the input end of the signal processing module;

[0011] The control module controls the state of the internal optocoupler according to the signal of the processor module, and determines the disconnection state together with the signal processing module and the disconnection detection module.

[0012] In one embodiment, the signal processing module includes: a first comparator and a first optical coupler;

[0013] The first terminal of the first comparator is connected to the power supply, the second terminal is connected to the signal input terminal, and the third terminal is connected to the second terminal of the first optical coupler;

[0014] The first end of the first optical coupler is connected to the power supply, and the third end is connected to the processor module.

[0015] In one embodiment, the signal processing module further includes: a first diode;

[0016] The first end of the first diode is connected to the signal input end and the second end of the first comparator at the same time, and the second end of the first diode is connected to the ground.

[0017] In one embodiment, the disconnection detection module includes: a second comparator and a second optical coupler;

[0018] The first terminal of the second comparator is connected to the power supply, the second terminal is connected to the signal input terminal, and the third terminal is connected to the first terminal of the second optical coupler;

[0019] The second end of the second optical coupler is connected to the ground, and the third end of the second optical coupler is connected to the processor module.

[0020] In one embodiment, the disconnection detection module further includes: a second diode;

[0021] The first end of the second diode is connected to the signal input end and the second end of the second comparator at the same time, and the second end of the second diode is connected to the ground.

[0022] In one embodiment, the control module includes: a third optical coupler;

[0023] The first end of the third optical coupler is connected to the processor module, the second end is connected to the power supply, and the third end outputs the input signal to the signal processing module and the disconnection detection module.

[0024] In one embodiment, the first comparator and the second comparator are of the model LM2901XP.

[0025] In one embodiment, the models of the first optocoupler, the second optocoupler, and the third optocoupler are: OR-3H7-4.

[0026] In one embodiment, the first diode and the second diode have a model number of MMSZ5245B.

[0027] The above-mentioned digital input device compatible with source and sink types is provided with a signal processing module, a processor module and a disconnection detection module. The digital signal inputted at the signal input end is received by the signal processing module and the disconnection detection module at the same time, and outputs a high level or a low level after passing through the operational amplifier and the optocoupler respectively. After being processed by the processor module, it is identified that the digital signal belongs to a source input or a sink input, thereby achieving compatibility between source type devices and sink type devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A schematic diagram of the structure of a digital input device compatible with source and sink types in one embodiment;

[0029] Figure 2 A circuit diagram of a digital input device compatible with both source and sink types in one embodiment;

[0030] Figure 3 is a schematic diagram of a signal processing module in one embodiment;

[0031] Figure 4 is an enlarged schematic diagram of the signal processing module A1 in one embodiment;

[0032] Figure 5 is an enlarged schematic diagram of the signal processing module A2 in one embodiment;

[0033] Figure 6 is a schematic diagram of a disconnection detection module in one embodiment;

[0034] Figure 7 This is an enlarged schematic diagram of the disconnection detection module B1 in one embodiment;

[0035] Figure 8 This is an enlarged schematic diagram of the disconnection detection module B2 in one embodiment;

[0036] Figure 9 is a schematic diagram of a control module in one embodiment;

[0037] Figure 10 is a schematic diagram of a processor module in one embodiment;

[0038] Figure 11 is an enlarged schematic diagram of a processor module D1 portion in one embodiment;

[0039] Figure 12 is an enlarged schematic diagram of a processor module D2 portion in one embodiment;

[0040] Figure 13 is an enlarged schematic diagram of a processor module D3 portion in one embodiment;

[0041] Figure 14 FIG. 4 is an enlarged schematic diagram of a processor module D4 in one embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0043] like Figure 1As shown, the present application provides a digital input device compatible with source type and sink type, in one embodiment, comprising: a signal processing module, a processor module and a disconnection detection module;

[0044] The input end of the signal processing module is connected to the signal input end, and the output end is connected to the input end of the processor module;

[0045] The input end of the processor module is connected to the output end of the signal processing module and the output end of the disconnection detection module, and the output end is connected to the signal output end;

[0046] The input terminal of the disconnection detection module is connected to the signal input terminal;

[0047] The signal processing module and the disconnection detection module simultaneously receive the digital signal input from the signal input end, and determine the level type of the digital signal through the operational amplifier and the optocoupler respectively. The processor module determines whether the digital signal belongs to source input or sink input according to the level type.

[0048] Preferably, the signal processing module includes: a first comparator and a first optical coupler;

[0049] The first end of the first comparator is connected to the power supply, the second end is connected to the signal input end, and the third end is connected to the second end of the first optocoupler; the first end of the first optocoupler is connected to the power supply, and the third end is connected to the processor module.

[0050] The disconnection detection module includes: a second comparator and a second optical coupler;

[0051] The first end of the second comparator is connected to the power supply, the second end is connected to the signal input end, and the third end is connected to the first end of the second optocoupler; the second end of the second optocoupler is connected to the ground, and the third end is connected to the processor module.

[0052] like Figure 2 As shown in FIG, it is a circuit diagram of a digital input device compatible with source type and sink type, wherein A is the circuit of the signal processing module, specifically as shown in FIG. Figure 3 As shown ( Figure 3 The enlarged schematic diagram of parts A1 and A2 is shown in Figure 4 and Figure 5 As shown), B is the circuit of the disconnection detection module, as shown in FIG. Figure 6 As shown ( Figure 6 The enlarged schematic diagram of parts B1 and B2 is shown in Figure 7 and Figure 8 As shown), C is the circuit of the control module, as shown in Figure 9 As shown, D is the circuit of the processor module, specifically as Figure 10 As shown ( Figure 10 The enlarged schematic diagram of D1, D2, D3 and D4 parts is shown in FIG. Figure 11 、 Figure 12 、 Figure 13 and Figure 14 shown).

[0053] In this embodiment, the input signal of the external device cannot enter the processor module directly, but can only be processed by the signal processing module first; the signal processing module is used to realize the processing of source type signals and sink type signals, specifically, the operational amplifier (i.e., the first comparator) processes the digital signal, and outputs a certain high level or low level to the first optocoupler, prompting the first optocoupler to turn on and off; the main function of the first optocoupler is to isolate the signal, and at the same time convert the high and low signals into high and low level signals that can be recognized by the processor module (because the high and low levels output by the first comparator or the high and low levels input by the device cannot be directly input into the processor module for recognition), and the input of the signal is judged by turning on and off the first optocoupler, completing the recognition of the input signal, and giving a certain signal to the processor module for signal processing; the processor module is used to realize signal processing, and is mainly composed of MCU (existing technology); the disconnection detection module is used to realize signal recognition and processing together with the signal processing module.

[0054] In PLC applications, the signal input wiring of digital input devices includes active input connection and sink input connection.

[0055] The source input connection method is for source type devices. The signal output by the source type device is low level. At this time, the signal input to the digital input device is also low level. When there is a low level connection, the signal is first processed by the signal processing module, and then given to the processor module for corresponding signal recognition.

[0056] The leakage input connection method is for leakage type devices. The signal output by the leakage type device is a high level. At this time, the signal input to the digital input device is a high level. When a high level is connected, the signal is first processed by the signal processing module and then given to the processor module for corresponding signal recognition.

[0057] The specific working process is: the rated value of the digital input signal is 24VDC, the "0" signal is -30V to +5V, that is, the low level, and the "1" signal is +13V to 30V, that is, the high level.

[0058] When a source type device is connected, the input signal DIN_CH0 is compared and processed by the first comparator. The low-level threshold voltage of the first comparator is 6.412V, thereby realizing the recognition of the low-level "0" signal: -30V to +5V. When the signal input is judged to be low level, the voltage at the first end of the first comparator is 6.412V, that is, Figure 3 The voltage of pin 7 (positive input) is 6.412V, which is higher than the voltage of the second terminal, that is, higher than Figure 3The voltage of pin 6 (reverse input) in the first comparator outputs a high level, that is, Figure 3 Pin 1 (output terminal) outputs high level; the second terminal of the first optocoupler (i.e. Figure 3 The 4th pin of the middle circuit) inputs a high level, the first optocoupler is cut off, and the third end (i.e. Figure 3 Pin 13) outputs the default high level.

[0059] Similarly, the input signal DIN_CH0 is compared and processed by the second comparator. The threshold level of the second comparator is 3.064V, thereby realizing the recognition of the low-level "0" signal: -30V to +5V. Through the resistor voltage divider, it is judged that the signal input is low level. The voltage at the second end of the second comparator is 3.064V, that is, Figure 4 The voltage of the middle pin 4 is 3.064V, which is lower than the voltage of the first terminal, that is, lower than Figure 4 The voltage of pin 5 in the second comparator outputs a high level, that is, Figure 4 Pin 2 outputs a high level; the first end of the second optocoupler (i.e. Figure 4 Pin 1) inputs a high level, the first optocoupler is turned on, and the third terminal (i.e. Figure 4 Pin 15) outputs high level.

[0060] When a sink type device is connected, the input signal DIN_CH0 is compared and processed by the first comparator. The high level threshold voltage of the first comparator is 9.097V, thereby realizing the recognition of the high level "1" signal: +13V to 30V. When the signal input is judged to be high level, the voltage of the first terminal of the first comparator is 9.097V, that is, Figure 3 The voltage of pin 7 (positive input) is 9.097V, which is lower than the voltage of the second terminal, that is, lower than Figure 3 The voltage of pin 6 (reverse input) in the first comparator outputs a low level, that is, Figure 3 Pin 1 (output terminal) outputs low level; the second terminal of the first optocoupler (i.e. Figure 3 The 4th pin of the middle circuit) inputs a low level, the first optocoupler is turned on, and the third terminal (i.e. Figure 3 Pin 13) outputs low level.

[0061] Similarly, the input signal DIN_CH0 is compared by the second comparator. The threshold level of the second comparator is 3.064V. When a high-level "1" signal (+13V to 30V) is input, the voltage at the second end of the second comparator is 3.064V. Figure 4 The voltage of the 4th pin is 3.064V, which is higher than the voltage of the first terminal, that is, higher than Figure 4 The voltage of pin 5 in the second comparator is low, that is, Figure 4 Pin 2 outputs a low level; the first end of the second optocoupler (i.e. Figure 4The input of pin 1 is low level, the second optocoupler is cut off, and the third end (i.e. Figure 4 Pin 15) outputs the default low level.

[0062] That is, when the processor module determines that the signal processing module and the disconnection detection module output high levels at the same time, the input signal is determined to be a source type; when the processor module determines that the signal processing module and the disconnection detection module output low levels at the same time, the input signal is determined to be a sink type.

[0063] Further preferably, the signal processing module further includes: a first diode; a first end of the first diode is connected to the signal input end and the second end of the first comparator at the same time, and a second end of the first diode is connected to the ground.

[0064] The disconnection detection module further includes: a second diode; a first end of the second diode is connected to the signal input end and the second end of the second comparator at the same time, and a second end of the second diode is connected to the ground.

[0065] The diodes (i.e., the first diode and the second diode) are voltage-stabilizing diodes. Their main function is to protect the comparators (i.e., the first comparator and the second comparator) from high and low levels of the device input, ensuring that the input level range of the second end of the comparator is -0.7V-15V.

[0066] In one embodiment, the further comprising: a control module;

[0067] The input end of the control module is connected to the output end of the processor module, and the output end is connected to the input end of the signal processing module;

[0068] The control module controls the state of the internal optocoupler according to the signal of the processor module to ensure that the optocoupler is always in the open state to ensure the level threshold of the signal input, thereby determining the disconnection state together with the signal processing module and the disconnection detection module.

[0069] Preferably, the control module includes: a third optical coupler;

[0070] The first end of the third optocoupler (i.e. Figure 5 The second end (pin 2) is connected to the processor module. Figure 5 Pin 1) is connected to the power supply, and the third terminal (i.e. Figure 5 The 15th pin in the middle outputs the input signal to the signal processing module and the disconnection detection module. The fourth terminal (i.e. Figure 5 Pin 16 is connected to the power supply. It should be noted that pins 1 and 16 share the same power supply.

[0071] In this embodiment, the control module is mainly composed of a third optocoupler, and the switch of the third optocoupler is controlled by the processor module to ensure that the third optocoupler is always in the open state. When the line is broken or no external device is connected, the control module gives a fixed electrical level to the input end of the line break detection module and the signal processing module, prompting the line break detection module to output a high electrical level and the signal processing module to output a low electrical level. In other words, the outputs of the line break detection module and the signal processing module are one high and one low. When there is a signal input, the electrical levels output by the line break detection module and the signal processing module are simultaneously high (source type device) or simultaneously low (sink type device). Therefore, the control module, the line break detection module, and the signal processing module together determine whether the line is broken, thereby realizing the source type and sink type line break detection functions.

[0072] Wire break detection is a critical technology in PLC applications. Digital input devices equipped with this function can better determine signal detection. The control module's configuration enables digital input devices to be compatible with both source and sink inputs, while also enabling wire break detection for both source and sink inputs.

[0073] When source type and sink type are connected, the disconnection detection function is monitored and judged by the disconnection detection module, signal processing module and control module at the same time to detect whether the link is disconnected.

[0074] The specific working process is:

[0075] When a source or sink device is connected and the line is broken, since the third optocoupler of the control module is turned on by default, the output of the third optocoupler is equivalent to adding a 39K pull-up to the input signal DIN_CH0 (note: it is not the input signal of the control module, but the input signal, which refers to the signal between the control module and the line break detection module). Through the voltage divider of the resistor, the signal input is guaranteed to have a default level. This default level is higher than the threshold level of the first comparator, and the first comparator outputs a low level, so the first optocoupler is in the on state and the output is a low level; at the same time, this default level is lower than the threshold level of the second comparator, and the second comparator outputs a high level, so the second optocoupler is in the on state and the output is a high level. From the above analysis, it can be seen that the output levels of the signal processing module and the line break detection module are different. When a device is connected, the output levels of the signal processing module and the line break detection module are either high or low at the same time, thereby determining whether the connected source or sink device is in a line break state.

[0076] In a specific embodiment, the models of the first comparator and the second comparator are LM2901XP, the models of the first optocoupler, the second optocoupler and the third optocoupler are OR-3H7-4, and the models of the first diode and the second diode are MMSZ5245B.

[0077] It should be noted that the signal processing module, the disconnection detection module and the control module also include capacitors and resistors. The relevant circuits are existing technologies and will not be described in detail here.

[0078] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A digital input device compatible with source type and sink type, characterized in that: include: Signal processing module, processor module and disconnection detection module; The input end of the signal processing module is connected to the signal input end, and the output end is connected to the input end of the processor module; The input end of the processor module is connected to the output end of the signal processing module and the output end of the disconnection detection module, and the output end is connected to the signal output end; The input end of the disconnection detection module is connected to the signal input end; The signal processing module and the disconnection detection module simultaneously receive the digital signal input from the signal input terminal, and respectively determine the level type of the digital signal through the operational amplifier and the optical coupler, and the processor module determines whether the digital signal is a source input or a sink input according to the level type; Also included: a control module; The input end of the control module is connected to the output end of the processor module, and the output end is connected to the input end of the signal processing module; The control module controls the state of the internal optocoupler according to the signal of the processor module, and determines the disconnection state together with the signal processing module and the disconnection detection module.

2. The digital input device according to claim 1, wherein: The signal processing module includes: a first comparator and a first optical coupler; The first terminal of the first comparator is connected to the power supply, the second terminal is connected to the signal input terminal, and the third terminal is connected to the second terminal of the first optical coupler; The first end of the first optical coupler is connected to the power supply, and the third end is connected to the processor module.

3. The digital input device according to claim 2, characterized in that: The signal processing module further includes: a first diode; The first end of the first diode is connected to the signal input end and the second end of the first comparator at the same time, and the second end of the first diode is connected to the ground.

4. The digital input device according to claim 3, characterized in that: The disconnection detection module includes: a second comparator and a second optical coupler; The first terminal of the second comparator is connected to the power supply, the second terminal is connected to the signal input terminal, and the third terminal is connected to the first terminal of the second optical coupler; The second end of the second optical coupler is connected to the ground, and the third end of the second optical coupler is connected to the processor module.

5. The digital input device according to claim 4, characterized in that: The disconnection detection module further includes: a second diode; The first end of the second diode is connected to the signal input end and the second end of the second comparator at the same time, and the second end of the second diode is connected to the ground.

6. The digital input device according to claim 5, characterized in that: The control module includes: a third optical coupler; The first end of the third optical coupler is connected to the processor module, the second end is connected to the power supply, and the third end outputs the input signal to the signal processing module and the disconnection detection module.

7. The digital input device according to any one of claims 4 to 6, characterized in that: The models of the first comparator and the second comparator are: LM2901XP.

8. The digital input device according to claim 6, characterized in that: The models of the first optocoupler, the second optocoupler, and the third optocoupler are: OR-3H7-4.

9. The digital input device according to claim 5 or 6, characterized in that: The models of the first diode and the second diode are: MMSZ5245B.

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