A multi-state status indicator control circuit and method for an encoder

Abstract

The application discloses a multi-state working indicator lamp control circuit and method for an encoder, which comprises a working state control unit (1), an extinguishing pulse width extension unit (2) and a light display unit (3), the input ends of the working state control unit (1) and the extinguishing pulse width extension unit (2) are electrically connected with an encoder subdivision unit (4) respectively, and the output ends of the working state control unit (1) and the extinguishing pulse width extension unit (2) are connected with the light display unit (3) respectively; the encoder subdivision unit (4) provides an alarm state signal XIRQ for the working state control unit (1), and the encoder subdivision unit (4) provides a Z_PULSE pulse signal generated by an index scale trigger for the extinguishing pulse width extension unit (2).

Description

Technical Field

[0001] This invention belongs to the field of encoder control technology, specifically relating to a control circuit and method for a multi-state working indicator light for an encoder. Background Technology

[0002] Encoders are widely used in industrial motion control. Incremental encoders typically have one or more index markings on their grating track to indicate the origin position. When the encoder detects an index marking, it outputs a Z_PULSE pulse signal to the host detection device. If the encoder's indicator light displays the corresponding status at this time, it greatly facilitates the user's installation, debugging, or inspection.

[0003] Due to the small size of encoders, high internal circuit integration, and limited interface resources, the microstepping ICs within encoders rarely have dedicated control pins for controlling the indicator lights. Furthermore, because the Z_PULSE pulse signal has a narrow pulse width, typically in the microsecond range (µs), the pulse width controlling the LED display is difficult to discern with the naked eye, necessitating a delay in the LED control signal's pulse width.

[0004] To overcome the above problems, the existing technical solution is as follows:

[0005] 1. Only two indicator states are available: running or alarm. When an index is in a stateless state, a prompt will be triggered.

[0006] 2. Add MCU and other control ICs to connect to the sub-ICs to achieve the above functions.

[0007] 3. Select a micro IC with work light control function.

[0008] The disadvantages of existing technology are:

[0009] 1. Disadvantages of not having index status indication:

[0010] The above solution only provides two types of indicator lights: running and alarm. When the encoder triggers the index scale, it can only parse the Z_PULSE signal output by the read head through the host device. The installation and debugging process of this solution is cumbersome.

[0011] 2. Disadvantages of adding microcontroller ICs (MCUs, etc.) to connect to subdivision ICs:

[0012] This approach requires adding an additional MCU or other control IC circuitry inside the encoder to establish communication with the subdivision IC. Controlling the work lights and other components is achieved by reading the internal status data of the subdivision IC. While this method allows for more flexible lighting control configurations, it also increases the encoder's BOM cost and PCB size, making it unsuitable for small-size or cost-sensitive encoder applications.

[0013] 3. Disadvantages of using a microcontroller IC with work light control function:

[0014] This niche IC market has very few product options; most are custom-made, making procurement extremely difficult.

[0015] Therefore, developing a control circuit for controlling the working indicator light inside the encoder has great market potential. Summary of the Invention

[0016] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-state working indicator light control circuit and method for encoders.

[0017] To solve the technical problem, the technical solution of the present invention is: a multi-state working indicator light control circuit for an encoder, including a working state control unit, an off pulse width extension unit and a light display unit, wherein the input terminals of the working state control unit and the off pulse width extension unit are respectively electrically connected to the encoder subdivision unit, and the output terminals of the working state control unit and the off pulse width extension unit are respectively connected to the light display unit.

[0018] The encoder subdivision unit provides an alarm status signal XIRQ to the working status control unit, and the encoder subdivision unit provides a Z_PULSE pulse signal generated by the index scale trigger to the extinguishing pulse width extension unit.

[0019] Preferably, the working status control unit consists of a NOT gate U1, an LED driving resistor R1, and an LED driving resistor R2. The alarm status signal XIRQ output by the encoder subdivision unit is connected to the input pin PIN2 of the NOT gate U1, the output pin PIN4 of the NOT gate U1 is connected to the pin PIN1 of the LED driving resistor R1, and the pin PIN2 of the LED driving resistor R1 outputs the working light driving signal RUN, which represents normal encoder operation, and the RUN signal is output to the light display unit. The input pin PIN1 of the LED driving resistor R2 is connected to the alarm status signal XIRQ, and the output pin PIN2 of the LED driving resistor R2 outputs the working light driving signal ERR, which represents an encoder alarm, and the ERR signal is output to the light display unit.

[0020] Preferably, when the encoder is working normally, the alarm status signal XIRQ is high and the output pin PIN4 of the NOT gate U1 is low; when the encoder alarms, the alarm status signal XIRQ is low and the output pin PIN4 of the NOT gate U1 is high.

[0021] Preferably, the extinguishing pulse width extension unit consists of a monostable logic chip U2, a capacitor C1, and a resistor R5. The Z_PULSE pulse signal generated by the index scale trigger output from the encoder subdivision unit is connected to the rising edge trigger input pin PIN2 of the monostable logic chip U2, and the falling edge trigger input pin PIN1 of the monostable logic chip U2 is connected to GND. The resistor R5 and capacitor C1 constitute a charging delay circuit. PIN1 of resistor R5 is connected to 3.3V, PIN2 of resistor R5 is connected to PIN1 of capacitor C1, PIN2 of capacitor C1 is connected to PIN6 of the monostable logic chip U2, PIN7 of the monostable logic chip U2 is connected to PIN2 of resistor R5, and PIN5 of the monostable logic chip U2 outputs the light extinguishing control signal OFF_LED to the light display unit.

[0022] Preferably, PIN3 of the monostable logic chip U2 is the input state clear pin (CLR). When the working indicator light is not controlled, PIN3 of the monostable logic chip U2 is connected to 3.3V; PIN8 of the monostable logic chip U2 is connected to 3.3V.

[0023] Preferably, the lighting display unit consists of a common anode dual-color LED indicator LED1, a transistor Q1, resistors R3 and R4. The RUN signal output by the working state control unit is connected to the first cathode of the common anode dual-color LED indicator LED1, and the ERR signal is connected to the second cathode of the common anode dual-color LED indicator LED1. The common anode of the common anode dual-color LED indicator LED1 is connected to the collector C of the transistor Q1 (PIN3). The emitter E of the transistor Q1 (PIN2) is connected to a 3.3V power supply. The light-off control signal OFF_LED output by the pulse width extension unit is input to PIN1 of resistor R4. PIN2 of resistor R4 is connected to the base B of the transistor Q1 (PIN1). Resistor R3 is connected to PIN1 and PIN2 of the transistor Q1, serving as a pull-up clamp.

[0024] Preferably, the transistor Q1 is a PNP type transistor Q1.

[0025] Preferably, the first light is a blue light and the second light is a red light.

[0026] Preferably, a method for controlling a multi-state operating indicator light for an encoder utilizes the aforementioned control circuit for a multi-state operating indicator light for an encoder. The control method includes the following:

[0027] The first scenario: When the encoder subdivision unit is working normally, the alarm status signal XIRQ is high, and the output pin PIN4 of the logic NOT gate U1 outputs a low level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has a driving current, and the blue light of the common anode dual-color LED indicator LED1 lights up. Since the alarm status signal XIRQ is high, the signal ERR has no driving current, and the red light of the common anode dual-color LED indicator LED1 does not light up.

[0028] The second scenario: When an alarm is generated by the encoder subdivision unit, the alarm status signal XIRQ is low, and the output pin PIN4 of the logic NOT gate U1 outputs a high level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has no driving current, and the blue light of the common anode dual-color LED indicator LED1 does not light up. Since the alarm status signal XIRQ is low, the signal ERR has driving current, and the red light of the common anode dual-color LED indicator LED1 lights up.

[0029] The third type: When the encoder subdivision unit has no Z_PULSE pulse signal output, the Z_PULSE pulse signal is low level, the PIN5 of the monostable logic chip U2 outputs the control signal OFF_LED to turn off the light and keeps it at a low level, the base of the transistor Q1 has current flowing through it, and the resistor R4 limits the base current so that the transistor Q1 remains on and works in the saturation region.

[0030] The fourth method: When the encoder subdivision unit outputs a Z_PULSE pulse signal, the rising edge of the Z_PULSE pulse signal is captured by PIN2 of the monostable logic chip U2. PIN5 of the monostable logic chip U2 outputs the light-off control signal OFF_LED, which rises synchronously. The high-level pulse width of the light-off control signal OFF_LED is Xms. After the light-off control signal OFF_LED rises, current flows through the base of transistor Q1, and transistor Q1 is turned off. At this time, regardless of whether the alarm status signal XIRQ is high or low, the blue and red lights of the common anode dual-color LED indicator LED1 are both off. After Xms, the light-off control signal OFF_LED returns to a low level, transistor Q1 is turned back on, and the blue or red light of the common anode dual-color LED indicator LED1 illuminates.

[0031] Preferably, the high-level pulse width of the light-off control signal OFF_LED is determined by the charging delay circuit composed of resistor R5 and capacitor C1. Adjusting the ratio of resistor R5 and capacitor C1 modifies the pulse width extension time, and the calculation formula is as follows:

[0032] X = K × R × C

[0033] In the formula:

[0034] X represents the duration of the pulse width extension, in milliseconds (ms).

[0035] K is the multiplier, usually taken as 0.925;

[0036] R is the resistance value of adjusting resistor R5, in kilohms;

[0037] C is the capacitance value of capacitor C1, in UF.

[0038] Compared with the prior art, the advantages of the present invention are as follows:

[0039] (1) This invention discloses a multi-state working indicator control circuit and method for an encoder, including a working state control unit, an extinguishing pulse width extension unit, and a light display unit. The working state control unit consists of a logic NOT gate U1, an LED driving resistor R1, and an LED driving resistor R2. The extinguishing pulse width extension unit consists of a monostable logic chip U2, a capacitor C1, and a resistor R5. The light display unit consists of a common anode dual-color LED indicator LED1, a transistor Q1, a resistor R3, and a resistor R4. The encoder subdivision unit 4 provides an alarm status signal XIRQ to the working state control unit 1. Sub-unit 4 provides the Z_PULSE pulse signal generated by the index scale trigger for the extinguishing pulse width extension unit 2. This invention provides a hardware circuit solution that requires very few control signals, has a simple and reliable peripheral circuit, strong circuit compatibility, and a simple installation and debugging environment. It can be used on a relatively common encoder subdivision IC solution, using only the alarm status output pin and Z_PULSE output pin of the subdivision IC to achieve three states of control of the encoder working indicator light, including normal operation, internal alarm, and brief extinguishing when passing the index scale. It is suitable for small-size or cost-sensitive encoder applications.

[0040] (2) The signal RUN output by the working status control unit of the present invention is connected to the first cathode of the common anode dual-color LED indicator LED1, and the signal ERR is connected to the second cathode of the common anode dual-color LED indicator LED1. Only one alarm status signal XIRQ is used to control the two LEDs to light up alternately. The encoder working status of the common anode dual-color LED indicator LED1 is expressed by lighting up one by one and turning off at the same time, which is easy to express and clear.

[0041] (3) The extinguishing pulse width extension unit of the present invention includes a monostable logic chip U2, a capacitor C1 and a resistor R5. The resistor R5 and the capacitor C1 constitute a charging delay circuit. The single pulse signal is delayed by the charging delay circuit, thereby extending the time for the LED to be synchronously extinguished. The extinguishing duration can be delayed to 100ms, achieving an effect that can be observed and distinguished by the naked eye. Attached Figure Description

[0042] Figure 1 This is a circuit block diagram of a multi-state operating indicator light control circuit for an encoder according to the present invention.

[0043] Figure 2 This is a circuit diagram of a multi-state working indicator light control circuit for an encoder according to the present invention.

[0044] Figure 3 The waveform of the line signal in this invention;

[0045] Figure 4 This is the line signal waveform of the present invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Working status control unit; 2. Extinguishing pulse width extension unit; 3. Light display unit; 4. Encoder subdivision unit. Detailed Implementation

[0048] The specific implementation of the present invention is described below with reference to embodiments:

[0049] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0050] Example 1

[0051] like Figure 1 As shown, the present invention discloses a multi-state working indicator control circuit for an encoder, including a working state control unit 1, an extinguishing pulse width extension unit 2, and a light display unit 3. The input terminals of the working state control unit 1 and the extinguishing pulse width extension unit 2 are electrically connected to the encoder subdivision unit 4, and the output terminals of the working state control unit 1 and the extinguishing pulse width extension unit 2 are connected to the light display unit 3.

[0052] The encoder subdivision unit 4 provides the alarm status signal XIRQ to the working status control unit 1, and the encoder subdivision unit 4 provides the Z_PULSE pulse signal generated by the index scale trigger to the extinguishing pulse width extension unit 2.

[0053] The encoder subdivision unit 4 is not within the scope of this invention. The encoder subdivision unit 4 provides the encoder alarm status signal XIRQ and the Z_PULSE pulse signal generated by the index scale trigger for this invention.

[0054] Example 2

[0055] like Figure 2 As shown, preferably, the working state control unit 1 consists of a NOT gate U1, an LED driving resistor R1, and an LED driving resistor R2. The alarm status signal XIRQ output by the encoder subdivision unit 4 is connected to the input pin PIN2 of the NOT gate U1, the output pin PIN4 of the NOT gate U1 is connected to the pin PIN1 of the LED driving resistor R1, and the pin PIN2 of the LED driving resistor R1 outputs the working light driving signal RUN, which represents normal operation of the encoder. The RUN signal is output to the light display unit 3. The input pin PIN1 of the LED driving resistor R2 is connected to the alarm status signal XIRQ, and the output pin PIN2 of the LED driving resistor R2 outputs the working light driving signal ERR, which represents an alarm in the encoder. The ERR signal is output to the light display unit 3.

[0056] Preferably, when the encoder is working normally, the alarm status signal XIRQ is high and the output pin PIN4 of the NOT gate U1 is low; when the encoder alarms, the alarm status signal XIRQ is low and the output pin PIN4 of the NOT gate U1 is high.

[0057] Example 3

[0058] like Figure 2 As shown, preferably, the extinguishing pulse width extension unit 2 consists of a monostable logic chip U2, a capacitor C1, and a resistor R5. The Z_PULSE pulse signal generated by the index scale trigger output by the encoder subdivision unit 4 is connected to the rising edge trigger input pin PIN2 of the monostable logic chip U2, and the falling edge trigger input pin PIN1 of the monostable logic chip U2 is connected to GND. The resistor R5 and the capacitor C1 constitute a charging delay circuit. The pin1 of the resistor R5 is connected to 3.3V, the pin2 of the resistor R5 is connected to the pin1 of the capacitor C1, the pin2 of the capacitor C1 is connected to the pin6 of the monostable logic chip U2, the pin7 of the monostable logic chip U2 is connected to the pin2 of the resistor R5, and the pin5 of the monostable logic chip U2 outputs the light extinguishing control signal OFF_LED to the light display unit 3.

[0059] like Figure 2 As shown, preferably, PIN3 of the monostable logic chip U2 is the input state clear pin CLR. When the working indicator light is not controlled, PIN3 of the monostable logic chip U2 is connected to 3.3V; PIN8 of the monostable logic chip U2 is connected to 3.3V.

[0060] The pulse width extension time can be modified by configuring the resistance and capacitance values ​​of resistors R5 and C1.

[0061] Example 4

[0062] like Figure 2 As shown, preferably, the light display unit 3 consists of a common anode dual-color LED indicator LED1, a transistor Q1, resistors R3 and R4. The signal RUN output by the working state control unit 1 is connected to the first cathode of the common anode dual-color LED indicator LED1, and the signal ERR is connected to the second cathode of the common anode dual-color LED indicator LED1. The common anode of the common anode dual-color LED indicator LED1 is connected to the collector C of the transistor Q1 (PIN3). The emitter E of the transistor Q1 (PIN2) is connected to a 3.3V power supply. The light-off control signal OFF_LED output by the pulse width extension unit 2 is input to the PIN1 of the resistor R4. The PIN2 of the resistor R4 is connected to the base B of the transistor Q1 (PIN1). The resistor R3 is connected to the PIN1 and PIN2 of the transistor Q1, serving as a pull-up clamp.

[0063] Preferably, the transistor Q1 is a PNP type transistor Q1.

[0064] Preferably, the first light is a blue light and the second light is a red light.

[0065] Preferably, circuit designs that can also be achieved by replacing other components with similar parameters are also included within the scope of this invention. For example, the model of the red and blue dual-color common anode LED of this invention can be replaced with LEDs of other colors, or two independent LEDs can replace the one common anode dual-color LED indicator LED1 in this example.

[0066] Example 5

[0067] like Figure 1 , 2 As shown, a preferred method for controlling a multi-state operating indicator light for an encoder utilizes the aforementioned control circuit for a multi-state operating indicator light for an encoder. The control method includes the following:

[0068] The first scenario: When the encoder subdivision unit 4 is working normally, the alarm status signal XIRQ is high, and the output pin PIN4 of the logic NOT gate U1 outputs a low level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has a driving current, and the blue light of the common anode dual-color LED indicator LED1 lights up. Since the alarm status signal XIRQ is high, the signal ERR has no driving current, and the red light of the common anode dual-color LED indicator LED1 does not light up.

[0069] The second scenario: When an alarm is generated in encoder subdivision unit 4, the alarm status signal XIRQ is low, and the output pin PIN4 of the logic NOT gate U1 outputs a high level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has no driving current, and the blue light of the common anode dual-color LED indicator LED1 does not light up. Since the alarm status signal XIRQ is low, the signal ERR has driving current, and the red light of the common anode dual-color LED indicator LED1 lights up.

[0070] The third type: When the encoder subdivision unit 4 has no Z_PULSE pulse signal output, the Z_PULSE pulse signal is low level, the PIN5 of the monostable logic chip U2 outputs the control signal OFF_LED to turn off the light and keeps it at a low level, the base of the transistor Q1 has current flowing through it, and the resistor R4 limits the base current so that the transistor Q1 remains on and works in the saturation region.

[0071] The fourth method: When the encoder subdivision unit 4 outputs a Z_PULSE pulse signal, the rising edge of the Z_PULSE pulse signal is captured by PIN2 of the monostable logic chip U2. PIN5 of the monostable logic chip U2 outputs the light-off control signal OFF_LED, which rises synchronously. The high-level pulse width of the light-off control signal OFF_LED is Xms. After the light-off control signal OFF_LED rises, current flows through the base of transistor Q1, and transistor Q1 is turned off. At this time, regardless of whether the alarm status signal XIRQ is high or low, the blue and red lights of the common anode dual-color LED indicator LED1 are both off. After Xms, the light-off control signal OFF_LED returns to low level, transistor Q1 is turned back on, and the blue or red light of the common anode dual-color LED indicator LED1 is lit.

[0072] Preferably, the high-level pulse width of the light-off control signal OFF_LED is determined by the charging delay circuit composed of resistor R5 and capacitor C1. Adjusting the ratio of resistor R5 and capacitor C1 modifies the pulse width extension time, and the calculation formula is as follows:

[0073] X = K × R × C

[0074] In the formula:

[0075] X represents the duration of the pulse width extension, in milliseconds (ms).

[0076] K is the multiplier, usually taken as 0.925;

[0077] R is the resistance value of adjusting resistor R5, in kilohms;

[0078] C is the capacitance value of capacitor C1, in UF.

[0079] Preferably, any modifications that achieve the same control effect using similar circuits by changing the signal logic level and the color selection of the light control are included within the scope of this invention.

[0080] Example 6

[0081] A multi-state working indicator light control circuit for an encoder includes a working state control unit 1, an off pulse width extension unit 2, and a light display unit 3, which are connected as described above.

[0082] In this embodiment, a 100K resistor and a 1UF capacitor are used, and the LED off pulse width is 100ms.

[0083] Work light status and truth table for XIRQ and Z_PULSE signals:

[0084] Work status signal XIRQ signal Z_PULSE Blue light status Red light status Normal and no Index trigger H L Chang Liang Constant Extinction Alarm and no Index triggered L L Constant Extinction Chang Liang Index trigger X H Briefly extinguished Briefly extinguished

[0085] The control circuit obtained in this embodiment is analyzed for its line signal waveform.

[0086] like Figure 3 The diagram shows the waveforms of the light control signals during operation and alarm states when the encoder is not triggered by an index. During normal operation without an alarm, the alarm status signal XIRQ outputs a high level. Since no Z_PULSE pulse signal is generated, the signal OFF_LED1 remains low. At this time, the control signal LED_BLUE1 for the blue LED outputs a high level, and the blue LED lights up. The control signal LED_RED1 for the red LED outputs a low level, and the red LED is off, indicating that the encoder is working normally. When an internal alarm is generated by the encoder, the alarm status signal XIRQ continuously outputs a low level. The control signals for the blue and red LEDs reverse their states; the blue LED is off, and the red LED lights up, indicating that the encoder is malfunctioning and triggering an alarm. When the alarm is cleared, the signal XIRQ returns to a high level, and the LED states return to normal.

[0087] like Figure 4The waveforms of the light control signals in the running and alarm states are shown when the encoder triggers the index. During normal operation without an alarm, the alarm state signal XIRQ outputs a high level, the blue LED lights up, and the red LED turns off. When the Z_PULSE signal triggers a high-level pulse, the OFF_LED2 signal rises from low to high, with its rising edge synchronized with the rising edge of the Z_PULSE signal. The high-level pulse width of the OFF_LED2 signal is set to 100ms in this example, as shown in the waveform. During the high-level period of the OFF_LED2 signal, the control signals LED_BLUE2 for the blue LED and LED_LED2 for the red LED remain low, and both the blue and red LEDs are temporarily off, indicating that the encoder has a high-pulse Z_PULSE signal input. After the 100ms high-level pulse width of the OFF_LED2 signal ends, it returns to a low level. The control logic for the blue and red LED states at this time is the same as when the encoder has no index trigger.

[0088] like Figure 3 , 4 As shown, the signal waveform logic is consistent with the design of this invention and meets the design requirements.

[0089] The working principle of this invention is as follows:

[0090] like Figure 1 As shown, this invention discloses a multi-state working indicator light control circuit for an encoder, including a working state control unit 1, an off pulse width extension unit 2, and a light display unit 3. The encoder subdivision unit 4 provides an alarm state signal XIRQ to the working state control unit 1, and provides a Z_PULSE pulse signal generated by the index scale trigger to the off pulse width extension unit 2. This invention is applied to the working indicator light drive control circuit of an industrial encoder. This invention only requires one alarm state signal XIRQ and one Z_PULSE pulse signal to realize dual-color LED expression through the light display unit 3: blue light on, red light off, running; red light on, blue light off, alarm; red and blue lights briefly off, triggering the index. At the same time, the resistor R5 and capacitor C1 of the off pulse width extension unit 2 constitute a charging delay circuit. Adjusting the ratio of resistor R5 and capacitor C1 is used to modify the pulse width extension time. The extension time is the trigger time of the LED's brief off state. The trigger time of the LED's brief off state is synchronized with the edge of the index pulse signal. The off-state duration can be delayed to 100ms, achieving an effect that can be observed and distinguished by the naked eye.

[0091] This invention discloses a multi-state operating indicator light control circuit and method for encoders, including an operating state control unit, an extinguishing pulse width extension unit, and an indicator light display unit. The operating state control unit consists of a logic NOT gate U1, an LED driving resistor R1, and an LED driving resistor R2. The extinguishing pulse width extension unit consists of a monostable logic chip U2, a capacitor C1, and a resistor R5. The indicator light display unit consists of a common anode dual-color LED indicator LED1, a transistor Q1, a resistor R3, and a resistor R4. The encoder subdivision unit 4 provides an alarm status signal XIRQ to the operating state control unit 1 and provides a Z_PULSE pulse signal generated by the index scale trigger to the extinguishing pulse width extension unit 2. This invention provides a hardware circuit solution that requires very few control signals, has a simple and reliable peripheral circuit, strong circuit compatibility, and a simple installation and debugging environment. It can be used on a relatively common encoder subdivision IC solution, using only the alarm status output pin and the Z_PULSE output pin of the subdivision IC to achieve three states of control for the encoder operating indicator light, including normal operation, internal alarm, and brief extinguishing when passing the index scale. It is suitable for small-size or cost-sensitive encoder applications.

[0092] The RUN signal output by the working status control unit of this invention is connected to the first cathode of the common anode dual-color LED indicator LED1, and the ERR signal is connected to the second cathode of the common anode dual-color LED indicator LED1. Only one alarm status signal XIRQ is used to control the two LEDs to light up alternately. The encoder working status of the common anode dual-color LED indicator LED1 is expressed by lighting up one by one and turning off at the same time, which is easy and clear.

[0093] The present invention includes a pulse width extension unit for extinguishing LEDs, comprising a monostable logic chip U2, a capacitor C1, and a resistor R5. The resistor R5 and the capacitor C1 constitute a charging delay circuit. By delaying the single pulse signal through the charging delay circuit, the time for the LED to be synchronously extinguished is extended. The extinguishing duration can be delayed to 100ms, achieving an effect that can be observed and distinguished by the naked eye.

[0094] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

[0095] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A multi-state operating indicator light control circuit for an encoder, characterized in that: It includes a working state control unit (1), an extinguishing pulse width extension unit (2) and a light display unit (3). The input terminals of the working state control unit (1) and the extinguishing pulse width extension unit (2) are electrically connected to the encoder subdivision unit (4), and the output terminals of the working state control unit (1) and the extinguishing pulse width extension unit (2) are connected to the light display unit (3). The encoder subdivision unit (4) provides the alarm status signal XIRQ to the working status control unit (1), and the encoder subdivision unit (4) provides the Z_PULSE pulse signal generated by the index scale trigger to the extinguishing pulse width extension unit (2); The working status control unit (1) consists of a NOT gate U1, an LED driving resistor R1, and an LED driving resistor R2. The alarm status signal XIRQ output by the encoder subdivision unit (4) is connected to the input pin PIN2 of the NOT gate U1. The output pin PIN4 of the NOT gate U1 is connected to the pin1 of the LED driving resistor R1. The pin2 of the LED driving resistor R1 outputs the working light driving signal RUN, which represents the normal operation of the encoder. The signal RUN is output to the light display unit (3). The input pin PIN1 of the LED driving resistor R2 is connected to the alarm status signal XIRQ. The output pin PIN2 of the LED driving resistor R2 outputs the working light driving signal ERR, which represents the presence of an alarm in the encoder. The signal ERR is output to the light display unit (3). When the encoder is working normally, the alarm status signal XIRQ is at a high level, and the output pin PIN4 of the NOT gate U1 outputs a low level. When the encoder has an alarm, the alarm status signal XIRQ is at a low level, and the output pin PIN4 of the NOT gate U1 outputs a high level. The extinguishing pulse width extension unit (2) consists of a monostable logic chip U2, a capacitor C1, and a resistor R5. The Z_PULSE pulse signal generated by the index scale trigger output by the encoder subdivision unit (4) is connected to the rising edge trigger input pin PIN2 of the monostable logic chip U2, and the falling edge trigger input pin PIN1 of the monostable logic chip U2 is connected to GND. The resistor R5 and the capacitor C1 constitute a charging delay circuit. The pin1 of the resistor R5 is connected to 3.3V, and the pin2 of the resistor R5 is connected to the pin of the capacitor C1.

1. PIN2 of capacitor C1 is connected to PIN6 of monostable logic chip U2, PIN7 of monostable logic chip U2 is connected to PIN2 of resistor R5, and PIN5 of monostable logic chip U2 outputs the control signal OFF_LED to turn off the light to the light display unit (3); PIN3 of monostable logic chip U2 is the input state clear pin CLR. When the working indicator light is not controlled, PIN3 of monostable logic chip U2 is connected to 3.3V; PIN8 of monostable logic chip U2 is connected to 3.3V; The lighting display unit (3) consists of a common anode dual-color LED indicator LED1, a transistor Q1, a resistor R3, and a resistor R4. The signal RUN output by the working state control unit (1) is connected to the first cathode of the common anode dual-color LED indicator LED1, and the signal ERR is connected to the second cathode of the common anode dual-color LED indicator LED1. The common anode of the common anode dual-color LED indicator LED1 is connected to the collector C of the transistor Q1 (PIN3). The emitter E of the transistor Q1 (PIN2) is connected to a 3.3V power supply. The control signal OFF_LED for turning off the light output by the pulse width extension unit (2) is input to the PIN1 of the resistor R4. The PIN2 of the resistor R4 is connected to the base B of the transistor Q1 (PIN1). The resistor R3 is connected to the PIN1 and PIN2 of the transistor Q1, which acts as a pull-up clamp.

2. The multi-state operating indicator light control circuit for an encoder according to claim 1, characterized in that: The transistor Q1 is a PNP type transistor Q1.

3. The multi-state operating indicator light control circuit for an encoder according to claim 1, characterized in that: The first light is blue, and the second light is red.

4. A method for controlling multi-state operating indicator lights for an encoder, characterized in that, The control method using the multi-state indicator light control circuit for an encoder as described in claim 1 includes the following: The first type: When the encoder subdivision unit (4) is working normally, the alarm status signal XIRQ is high level, and the output pin PIN4 of the logic NOT gate U1 outputs a low level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has a driving current, and the blue light of the common anode dual-color LED indicator LED1 is lit. Since the alarm status signal XIRQ is high level, the signal ERR has no driving current, and the red light of the common anode dual-color LED indicator LED1 is not lit. The second type: When an alarm is generated by the encoder subdivision unit (4), the alarm status signal XIRQ is low and the output pin PIN4 of the logic NOT gate U1 outputs a high level. If there is no Z_PULSE pulse signal input at this time, the transistor Q1 is in the on state, the signal RUN has no driving current, and the blue light of the common anode dual-color LED indicator LED1 does not light up. Since the alarm status signal XIRQ is low, the signal ERR has driving current, and the red light of the common anode dual-color LED indicator LED1 lights up. The third type: When the encoder subdivision unit (4) has no Z_PULSE pulse signal output, the Z_PULSE pulse signal is low level, the PIN5 of the monostable logic chip U2 outputs the control signal OFF_LED to turn off the light and keeps it at a low level, the base of the transistor Q1 has current flowing through it, and the resistor R4 limits the base current so that the transistor Q1 remains on and works in the saturation region. The fourth type: When the encoder subdivision unit (4) outputs a Z_PULSE pulse signal, the rising edge of the Z_PULSE pulse signal is captured by PIN2 of the monostable logic chip U2, and the PIN5 of the monostable logic chip U2 outputs the light-off control signal OFF_LED synchronously rises. The high-level pulse width of the light-off control signal OFF_LED is Xms. After the light-off control signal OFF_LED rises, current flows through the base of transistor Q1, and transistor Q1 is turned off. At this time, regardless of whether the alarm status signal XIRQ is high or low, the blue and red lights of the common anode dual-color LED indicator LED1 are turned off. After Xms, the light-off control signal OFF_LED returns to low level, transistor Q1 is turned on again, and the blue or red light of the common anode dual-color LED indicator LED1 is lit.

5. The method for controlling multi-state operating indicator lights for an encoder according to claim 4, characterized in that: The high-level pulse width of the light-off control signal OFF_LED is determined by the charging delay circuit composed of resistor R5 and capacitor C1. Adjusting the ratio of resistor R5 and capacitor C1 modifies the pulse width extension time. The calculation formula is as follows: X = K * R * C In the formula: X represents the duration of the pulse width extension, in milliseconds (ms). K is the multiplier, usually taken as 0.925; R is the resistance value of adjusting resistor R5, Kohm; C is the capacitance value of capacitor C1, in UF.

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