CN117175336A - Laser electric control system integrating optical gate/optical coupler and control method thereof - Google Patents

Abstract

The application is suitable for the field of lasers and provides a laser electric control system integrating an optical gate/optical coupler. The laser electronic control system comprises a multichannel optical gate, a laser and an optical gate/optical coupler controller integrated in a cabinet of the laser, wherein the multichannel optical gate and the laser share laser upper computer monitoring software or mobile terminal monitoring APP, monitor states of the multichannel optical gate and the laser and realize a remote upgrading function; the multichannel optical gate is communicated with the laser through a bus; the multichannel optical gate outputs multipath optical signals at the same time, for the multichannel optical gate controlled by time sharing, the optical gate/optical coupler controller controls to randomly switch and connect processing stations corresponding to a plurality of channels for operation, and for the multichannel optical gate controlled by energy splitting, the optical gate/optical coupler controller selects the processing stations corresponding to the channels for operation according to the power, the output core diameter and/or the light spot type of the plurality of channels. The laser electric control system is convenient to detach and install, convenient for integrating different subsequent products, free from repeated design, unified in BOM, material-saving, research and development cost-saving and simple and convenient to operate.

Description

Laser electric control system integrating optical gate/optical coupler and control method thereof

Technical Field

The application belongs to the field of lasers, and particularly relates to a laser electric control system integrating an optical gate/optical coupler and a control method thereof.

Background

The output core diameter size, the light spot type and the rated power of the optical fiber before leaving the factory of the laser in the existing market are uniquely determined. The customer of the cutting application can select a Gaussian light spot small-core-diameter laser, the customer of the cladding application can select a flat-top light spot large-core-diameter laser, the customer of the marking application can select a low-power high-speed impulse response laser, and the customer of the welding application can select a dual-wavelength and dual-core-diameter control output laser. The customer selects lasers with different parameter specifications according to the requirements of different scene applications. However, the price of the laser is still high at present, so that the customer can pay a large amount of money to purchase a plurality of lasers with different parameter types for independent operation in different pipelines or workshops in order to meet the demands of simultaneous operation of different processing production lines. The laser has high processing efficiency, generally, motion control can occupy a large amount of time in the processing process, the real laser has short light emitting time, the full power output utilization rate of laser is low, and the simultaneous multiple functions of one machine cannot be realized. At present, most of product forms are that when the optical gate/optical coupler is matched with the laser for use, two independent products are used in an isolated mode, and when the states and alarms of the optical gate/optical coupler and the laser are monitored, software corresponding to the optical gate/optical coupler and software corresponding to the laser are required to be independently opened for checking, so that the operation is troublesome.

Disclosure of Invention

The application aims to provide a laser electric control system integrating an optical gate/optical coupler and a control method thereof, and aims to solve the problems that the existing laser cannot realize one machine with multiple functions at the same time, and when the states and alarms of the optical gate/optical coupler and the laser are monitored, software corresponding to the optical gate/optical coupler and software corresponding to the laser are required to be independently opened for checking, and operation is troublesome.

In a first aspect, the application provides a laser electronic control system integrating an optical gate/optical coupler, the laser electronic control system comprises a multichannel optical gate, a laser and an optical gate/optical coupler controller integrated in a cabinet of the laser, wherein the multichannel optical gate and the laser share laser upper computer monitoring software or mobile terminal monitoring APP, monitor states of the multichannel optical gate and the laser and realize remote upgrading functions; the multichannel optical gate is communicated with the laser through a bus; the multichannel optical gate outputs multipath optical signals at the same time, for the multichannel optical gate controlled by time sharing, the optical gate/optical coupler controller controls to randomly switch and connect processing stations corresponding to a plurality of channels for operation, and for the multichannel optical gate controlled by energy splitting, the optical gate/optical coupler controller selects the processing stations corresponding to the channels for operation according to the power, the output core diameter and/or the light spot type of the plurality of channels.

In a second aspect, the present application provides a control method for a laser electronic control system integrated with an optical shutter/optocoupler, the control method comprising the steps of:

s101, when a laser electric control system integrated with an optical gate/optical coupler is electrified, a main control chip firstly detects the power supply voltage controlled by a motor, turns on a power supply switch controlled by the motor under the condition of no alarm and detects the load current of the motor in real time, and data of a register are read and written through an SPI to ensure the normal operation of a stepping motor driving chip;

s102, driving motors to return to zero through a T-shaped acceleration algorithm, and simultaneously sequentially scanning the switches of the Hall position sensors at the two ends of the optical gate by a plurality of motors to return to zero through software, so that the effectiveness of the switch limit of the optical gate channel is ensured; the switching of the optical gate channel adopts an S-shaped interpolation control algorithm to realize real-time position control;

s103, a stepping motor driving chip outputs two paths of PWM signals with dead zones in upper and lower complementary modes, the PWM signals are filtered to an H-bridge MOS tube driving circuit, PWM modulation is completed, and the output signals drive a two-phase four-wire motor; two Hall position sensors arranged on each optical gate channel detect the position of the motor, and detection signals are fed back to the main control chip to form closed-loop control.

In the application, the optical gate/optical coupler controller is integrated in the cabinet of the laser, namely in a modularized design, so that the laser is convenient to detach and install, different subsequent products are convenient to integrate, repeated design is avoided, BOM is unified, and materials and research and development cost are saved. And because the multichannel optical gate and the laser share the laser upper computer monitoring software or the mobile terminal monitoring APP, the states of the multichannel optical gate and the laser are monitored, and the remote upgrading function is realized, the operation is simple and convenient. And because the multichannel optical gate outputs multiple paths of optical signals at the same time, the laser can realize multiple purposes at the same time. And because the optical gate/optical coupler is integrated in the laser, the interlocking protection can be formed, and the safety of the laser equipment can be improved. Because the motors are driven by the T-shaped acceleration algorithm to carry out zero return operation, a plurality of motors simultaneously and sequentially scan the switches of the Hall position sensors at the two ends of the optical gate to carry out software zero return operation, the effectiveness of the switch limit of the optical gate channel can be ensured; and because the switching of the optical gate channel adopts an S-shaped interpolation control algorithm, the high-efficiency real-time position control can be realized.

Drawings

Fig. 1 is a schematic diagram of a laser electronic control system integrated with an optical shutter/optocoupler according to an embodiment of the present application.

Fig. 2 is a schematic diagram of an optical gate/optocoupler controller in a laser electronic control system integrated with the optical gate/optocoupler according to an embodiment of the present application.

Fig. 3 is a schematic diagram of a closed-loop motor-based shutter switching channel control system according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantageous effects of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

In order to illustrate the technical scheme of the application, the following description is made by specific examples.

Referring to fig. 1, an integrated optical gate/optocoupler laser electronic control system provided by the embodiment of the application includes a multi-channel optical gate 10, a laser 20 and an optical gate/optocoupler controller 30 integrated in a cabinet of the laser, where the multi-channel optical gate 10 and the laser 20 share a laser upper computer monitoring software or a mobile terminal monitoring APP to monitor states of the multi-channel optical gate and the laser and realize a remote upgrading function; the multi-channel optical gate 10 and the laser 20 are communicated through a bus (such as RS 485); the multi-channel optical gate 10 outputs multiple optical signals at the same time, for the multi-channel optical gate controlled by time sharing, the optical gate/optical coupler controller can be controlled to be switched and connected with the processing stations corresponding to the multiple channels at will to operate, and for the multi-channel optical gate controlled by energy splitting, the optical gate/optical coupler controller selects the processing stations corresponding to the channels to operate according to the power, the output core diameter and/or the light spot type of the multiple channels.

In the embodiment of the application, the laser of the integrated optical gate/optical coupler can be connected with the laser control system of the client by means of an external control IO or an industrial field bus. Thus, the system and hardware interfaces of high, medium and low grade can be satisfied.

The external control signal interface of the external control IO is provided with: double emergency stop, double interlocking, channel selection, channel feedback Ready, alarm, enabling, light emitting, 0-10V, PWM light emitting power, red light, resetting, key switch, light emitting signal, main power state, emergency stop output, light returning power and the like.

Industrial field buses include EtherCAT bus, modbus bus-RTU, modbus-TCP, profinet, profibus, CANopen, CC-Link and the like.

The processing stations may be cutting lines, welding lines, cladding lines, marking lines, etc.

In the embodiment of the application, the optical gate/optical coupler controller is integrated in the cabinet of the laser, namely in a modularized design, so that the laser is convenient to detach and install, different subsequent products are convenient to integrate, repeated design is avoided, BOM is unified, and materials and research and development cost are saved. And because the multichannel optical gate and the laser share the laser upper computer monitoring software or the mobile terminal monitoring APP, the states of the multichannel optical gate and the laser are monitored, and the remote upgrading function is realized, the operation is simple and convenient. And because the multichannel optical gate outputs multiple paths of optical signals at the same time, the laser can realize multiple purposes at the same time. And because the optical gate/optical coupler is integrated in the laser, the interlocking protection can be formed, and the safety of the laser equipment can be improved.

Referring to fig. 2, the optical gate/optocoupler controller includes a main control chip 40, and a bus communication chip 50 and an FPGA chip 60 respectively connected to the main control chip 40, where the bus communication chip 50 is also connected to the FPGA chip 60; serial or SPI communication is adopted between the bus communication chip 50 and the main control chip 40 and the FPGA chip 60.

When the optical gate/optical coupler is in a single product form, in an internal control mode, serial port or Bluetooth communication is adopted between the main control chip 40 and the laser upper computer, the laser upper computer monitors the states of the multichannel optical gate and the laser and realizes a remote upgrading function, and parameters and alarm thresholds can be set; in the external control mode, the main control chip 40 reads the external control interface signal to realize the control of the optical gate/optical coupler and the feedback of state alarm; the main control chip 40 reads the hardware version information through the version reading interface to realize traceability of the software and hardware version, and the main control chip 40 records the operation instruction and the alarm state information in real time through the RTC circuit and the SD card read-write circuit, so that the fault problem can be conveniently analyzed according to the time stamp; when a fatal alarm fault occurs, a buzzer connected with the main control chip 40 gives an alarm; data are transmitted between the main control chip 40 and the laser through a serial port 485 bus; when the multichannel optical gate is integrated in the laser, the laser upper computer is uniformly used; the main control chip 40 is also used for switching the channel of the optical gate, and the main control chip 40 configures subdivision, current, operation mode, rotating speed, alarm code, status code and the like of the motor through the SPI; the stepping motor driving chip (such as TMC5160 chip) is controlled by enabling, pulsing and direction, and the driving motor moves at high speed dynamically, so that the rapid switching of the optical gate channel is realized.

Bus communication chip 50 for bus communication of EtherCAT, CANopen, RS, RS485, etc. and connected to laser control system of client or programmable logic controller of machine tool

Programmable Logic Controller, PLC); the bus communication chip 50 acquires sensor information data of the laser, motor control information and alarm state information of the optical gate in real time;

the FPGA chip 60 is used for collecting the temperature and humidity of the optical fiber input channel and the temperature and humidity of the optical fiber output channels and the PD light intensity voltage, comparing and outputting alarm codes, and reporting the alarm codes to the system through an external control IO interface or a bus protocol. When the coupling efficiency of the optical gate is reduced, the adjustment of the optical gate is performed through the coupling adjusting cylinder. The FPGA chip 60 collects the PD of fine and coarse adjustment, and synchronously outputs 0-10V voltage of coupling adjustment cylinder fine adjustment and coarse adjustment, and is connected to an external metal detection contact and a monitoring interface of a laser upper computer. When the optimal coupling efficiency is achieved, fine tuning is started until the output of the fine tuning voltage is the lowest, and the calibration is completed. The adjusting cylinder synchronously detects the coupling efficiency and the temperature, generates an alarm when the threshold value is reached, and triggers the alarm through a temperature switch when the temperature rises rapidly. The two measuring ranges of the fine adjustment and the coarse adjustment are switched, so that the laser coupling efficiency can be easily adjusted, and the maintenance and adjustment of a client are facilitated.

Further, the FPGA chip 60 monitors and collects the status information of the PD light intensity, temperature and humidity, and QBH of the optical gate/optical coupler, and then transmits the collected data to the main control chip 40 and the bus communication chip 50 through the SPI protocol; when the deadly alarm needs to be immediately cut off, an alarm is generated through an IO signal of hardware and output to a laser or a notification system for immediately cutting off the light, and a specific state code and a fault code are output to the system through an SPI protocol. When the FPGA chip 60 is powered on, the external Flash is used for starting, and when the remote upgrade is performed, the main control chip 40 writes in the Flash, and then the FPGA chip 60 is powered on, and the remote upgrade is realized from the external Flash. The initialization process detects the validity of the PD sensor first, the multi-channel outputs red light for 20ms and then turns off, and the scattered light PD sensor detects whether there is a corresponding PD voltage of 20 ms. The temperature and humidity sensor on board with the IIC interface is arranged on the board card of the FPGA chip 60, so that the temperature and humidity of the electric module are monitored in real time, and the short circuit and optical fiber burning caused by the high temperature and dew condensation are avoided. The FPGA chip 60 can also read the external hardware version, so as to realize the traceability of the software and hardware version of the product shipment and improve the convenience after sale. The FPGA chip 60 collects multiple paths of IO signals, which are an optical fiber installation state of each output channel, an optical fiber installation state of an input channel, a temperature switch of the input channel, a water flow switch of the input channel, and a temperature switch of the regulating cylinder, respectively. The FPGA chip 30 outputs multiple red light indication signals and multiple self-test LED signals. The FPGA chip 30 collects multiple analog signals, which are respectively the fine adjustment PD, the coarse adjustment PD, the scattered light PD, the channel temperature, the first output temperature, and the second output temperature of each output channel, and the forward light PD, the channel temperature, the housing temperature, the coupling efficiency PD of the adjustment cylinder, and the adjustment cylinder temperature of the input channels. The FPGA chip 30 outputs multiple analog signals, namely a fine tuning voltage and a coarse tuning voltage for each channel.

In the embodiment of the present application, the model of the main control chip 40 may be GD32F427ZGT7, the model of the bus communication chip 50 may be XMC4300, and the model of the FPGA chip 60 may be 30GW2A-55K-UBGA324.

Referring to fig. 3, the integrated optical gate/optocoupler laser electronic control system provided in the embodiment of the present application further includes an optical gate switching channel control system based on a closed-loop motor, where the optical gate switching channel control system based on the closed-loop motor includes a main control chip 71 of the optical gate/optocoupler controller, a plurality of stepping motor driving chips 72 (e.g. TMC 5160) connected to the main control chip 71, H-bridge MOS transistor driving circuits 73 respectively connected to each stepping motor driving chip 72, and motors 74 respectively connected to each H-bridge MOS transistor driving circuit 73, each optical gate channel is provided with two hall position sensors 75 for detecting the positions of the motors, and detection signals are fed back to the main control chip 71 to form closed-loop control. The optical gate switching channel control system based on the closed-loop motor can realize the fast and real-time synchronous switching of the laser output channels, reduce the time delay and improve the user switching efficiency of the client.

The embodiment of the application also provides a control method of the laser electric control system of the integrated optical gate/optical coupler, which comprises the following steps:

s101, when a laser electric control system integrating an optical gate/optical coupler is electrified, a main control chip firstly detects the power supply voltage controlled by the motor in order to ensure that a multichannel motor has the capacity of switching the optical gate channel, and under the condition of no alarm, the power supply switch controlled by the motor is turned on and the motor load current is detected in real time, and the data of a register is read and written through an SPI (serial peripheral interface) to ensure the normal operation of the stepping motor driving chip.

S102, driving motors to return to zero through a T-shaped acceleration algorithm, and simultaneously and sequentially scanning Hall position sensors at two ends of an optical shutter through a plurality of motorsPerforming a software zeroing operation to ensure the effectiveness of the switch limit of the optical gate channel; the software zeroing operation adopts a T-shaped acceleration and deceleration algorithm, and the formula of the T-shaped acceleration and deceleration speed and time is V=a t+vo; the formula of the position and time is: s=vo×t+0.5at≡2. Wherein Vo is the initial speed, V is the target speed, a is acceleration, t is time, V is the target speed, vo is the initial speed, and S is the target position; the switching of the optical gate channel adopts an S-shaped interpolation control algorithm, so that the high-efficiency real-time position control can be realized, and the formula of the S-shaped acceleration and deceleration speed and time is V (t) =A+B/(1+e) ^at+b ) The formula of the position and time is:where V (t) is the target speed, A is the initial speed (the offset coefficient of the speed coordinate), B is the stretch coefficient of the speed coordinate, t is the time, a is the stretch coefficient of the time coordinate, B is the offset coefficient of the time coordinate, e is the mathematical coefficient, S (t) is the position, and d (t) is the derivative of the position.

S103, a stepping motor driving chip outputs two paths of PWM signals with dead zones in upper and lower complementary modes, the PWM signals are filtered to an H-bridge MOS tube driving circuit, PWM modulation is completed, and the output signals drive a two-phase four-wire motor; two Hall position sensors arranged on each optical gate channel detect the position of the motor, and detection signals are fed back to the main control chip to form closed-loop control.

The control method of the laser electronic control system of the integrated optical gate/optical coupler can improve the light-emitting safety of the light path of the laser.

In the embodiment of the application, the laser electric control method of the integrated optical gate/optical coupler can further comprise the following steps:

when the two-way interlocking triggers the rising edge (namely, the logic is 0-1), and the time delay between the two-way interlocking is less than the preset time length, such as 150ms, no alarm is given;

any one of the interlocking level states is invalid, and an alarm is given;

any interlocking rising edge state is invalid, and an alarm is given;

if the time delay between the two-way interlocks exceeds a preset time length, such as 150ms, an alarm is given;

when any alarm is given by the external control double-way interlocking of the optical gate, all channels of the control optical gate do not allow light to be emitted.

In the application, the optical gate/optical coupler controller is integrated in the cabinet of the laser, namely in a modularized design, so that the laser is convenient to detach and install, different subsequent products are convenient to integrate, repeated design is avoided, BOM is unified, and materials and research and development cost are saved. And because the multichannel optical gate and the laser share the laser upper computer monitoring software or the mobile terminal monitoring APP, the states of the multichannel optical gate and the laser are monitored, and the remote upgrading function is realized, the operation is simple and convenient. And because the multichannel optical gate outputs multiple paths of optical signals at the same time, the laser can realize multiple purposes at the same time. And because the optical gate/optical coupler is integrated in the laser, the interlocking protection can be formed, and the safety of the laser equipment can be improved. Because the motors are driven by the T-shaped acceleration algorithm to carry out zero return operation, a plurality of motors simultaneously and sequentially scan the switches of the Hall position sensors at the two ends of the optical gate to carry out software zero return operation, the effectiveness of the switch limit of the optical gate channel can be ensured; and because the switching of the optical gate channel adopts an S-shaped interpolation control algorithm, the high-efficiency real-time position control can be realized.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims (10)

1. The laser electronic control system is characterized by comprising a multichannel optical gate, a laser and an optical gate/optical coupler controller integrated in a cabinet of the laser, wherein the multichannel optical gate and the laser share laser upper computer monitoring software or mobile terminal monitoring APP, monitor states of the multichannel optical gate and the laser and realize a remote upgrading function; the multichannel optical gate is communicated with the laser through a bus; the multichannel optical gate outputs multipath optical signals at the same time, for the multichannel optical gate controlled by time sharing, the optical gate/optical coupler controller controls to randomly switch and connect processing stations corresponding to a plurality of channels for operation, and for the multichannel optical gate controlled by energy splitting, the optical gate/optical coupler controller selects the processing stations corresponding to the channels for operation according to the power, the output core diameter and/or the light spot type of the plurality of channels.

2. The laser electronic control system of claim 1, wherein the shutter/optocoupler controller comprises a master control chip, and a bus communication chip and an FPGA chip respectively connected with the master control chip, the bus communication chip being further connected with the FPGA chip.

3. The laser electronic control system as claimed in claim 2, wherein when the shutter/optocoupler is in a single product form, serial port or bluetooth communication is adopted between the main control chip and the laser upper computer in the internal control mode, and the laser upper computer monitors states of the multichannel shutter and the laser and realizes a remote upgrading function; in the external control mode, the main control chip reads the external control interface signal to realize the control of the optical gate/optical coupler and the feedback of state alarm; the main control chip reads hardware version information through the version reading interface to realize traceability of software and hardware versions, and records operation instructions and alarm state information in real time through the RTC circuit and the SD card read-write circuit; the main control chip is also used for switching the channel of the optical gate, and the main control chip is used for controlling the stepping motor to drive and control the chip through enabling, pulsing and direction by configuring the motor through the SPI.

4. The laser electronic control system of claim 2, wherein the bus communication chip is connected with a laser control system of a client or a programmable logic controller of a machine tool; the bus communication chip actively searches and acquires sensor information data of the laser and motor control information and alarm state information of the optical gate in real time.

5. The laser electronic control system of claim 2, wherein the FPGA chip is configured to collect the temperature and humidity of the optical fiber input channel and the temperature and humidity of the PD optical fiber output channel, compare and output an alarm code, and report the alarm code to the system through an external control IO interface or a bus protocol.

6. The laser control system of claim 5, further comprising a coupling adjustment cylinder through which correction is made when the shutter coupling efficiency decreases; the FPGA chip collects the fine and coarse PD, synchronously outputs the voltage of the fine and coarse adjustment of the coupling adjustment cylinder, and connects the voltage to an external metal detection contact and a monitoring interface of the laser upper computer; the adjusting cylinder synchronously detects the coupling efficiency and the temperature, generates an alarm when the threshold value is reached, and triggers the alarm through a temperature switch when the temperature rises rapidly.

7. The laser electronic control system according to claim 2, further comprising a closed-loop motor-based shutter switching channel control system, wherein the closed-loop motor-based shutter switching channel control system comprises a master control chip of a shutter/optocoupler controller, a plurality of stepping motor driving and controlling chips connected with the master control chip, an H-bridge MOS tube driving circuit connected with each stepping motor driving and controlling chip respectively, and a motor connected with each H-bridge MOS tube driving circuit respectively, each shutter channel is provided with two Hall position sensors for detecting the positions of the motors, and detection signals are fed back to the master control chip to form closed-loop control.

8. A method of controlling an integrated shutter/optocoupler laser electronic control system of claim 7, wherein the method of controlling comprises the steps of:

s101, when a laser electric control system integrated with an optical gate/optical coupler is electrified, a main control chip firstly detects the power supply voltage controlled by a motor, turns on a power supply switch controlled by the motor under the condition of no alarm and detects the load current of the motor in real time, and data of a register are read and written through an SPI to ensure the normal operation of a stepping motor driving chip;

s102, driving motors to return to zero through a T-shaped acceleration algorithm, and simultaneously sequentially scanning the switches of the Hall position sensors at the two ends of the optical gate by a plurality of motors to return to zero through software, so that the effectiveness of the switch limit of the optical gate channel is ensured; the switching of the optical gate channel adopts an S-shaped interpolation control algorithm to realize real-time position control;

s103, a stepping motor driving chip outputs two paths of PWM signals with dead zones in upper and lower complementary modes, the PWM signals are filtered to an H-bridge MOS tube driving circuit, PWM modulation is completed, and the output signals drive a two-phase four-wire motor; two Hall position sensors arranged on each optical gate channel detect the position of the motor, and detection signals are fed back to the main control chip to form closed-loop control.

9. The control method according to claim 8, wherein the software zeroing operation adopts a T-type acceleration and deceleration algorithm, and the formula of the T-type acceleration and deceleration speed and time is V=a×t+vo; the formula of the position and time is: s=vo×t+0.5at≡2. Wherein Vo is the initial speed, V is the target speed, a is acceleration, t is time, V is the target speed, vo is the initial speed, and S is the target position;

in the S-shaped interpolation control algorithm, the formula of the S-shaped acceleration and deceleration speed and time is V (t) =A+B/(1+e) ^at+b ) The formula of the position and time is:wherein V (t) is the target speed, a is the initial speed, B is the stretch factor of the speed coordinate, t is the time, a is the stretch factor of the time coordinate, B is the offset factor of the time coordinate, e is the mathematical factor, S (t) is the position, and d (t) is the derivative of the position.

10. The control method according to claim 8, characterized in that the control method further comprises the steps of:

when the double-way interlocking triggers the rising edge, and the time delay between the double-way interlocking is less than the preset time length, no alarm is given;

any one of the interlocking level states is invalid or the rising edge state is invalid, and an alarm is given;

if the time delay between the two-way interlocks exceeds the preset time length, alarming;

when any alarm is given by the external control double-way interlocking of the optical gate, all channels of the control optical gate do not allow light to be emitted.