A method and device for temperature-controlled delayed start-up of an extruder based on S7-300 PLC

Abstract

This invention discloses a temperature-controlled delayed start control method and device for an extruder based on an S7-300 PLC. The method includes: pre-creating a stateless standard function block in the S7-300 PLC; uploading the current actual temperature of the extruder barrel, the process set temperature, an external start request signal, and a preset fixed delay time to the stateless standard function block; the stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature; if so, it starts a timer instance stored in a global data block; when the timer instance's timing duration reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder's main motor. The technical solution provided by this invention can effectively improve equipment operating safety and service life.

Description

Technical Field

[0001] This invention relates to the field of industrial automation control technology, and in particular to a temperature-controlled delayed start control method and device for an extruder based on an S7-300 PLC. Background Technology

[0002] Existing extruder start-up control methods directly control the output via ladder diagrams or trigger motor operation directly via the "start" button on the Human Machine Interface (HMI), without requiring temperature sensor values ​​to be greater than or equal to a set value, allowing the main motor to start at any time. However, this method has the following drawbacks:

[0003] (1) Relying solely on personnel to determine if the temperature meets the standard ignores the lag in heat conduction between the barrel metal and the internal material, resulting in the phenomenon that the material in the center of the screw may still be cold even when the temperature display shows that it meets the standard. (2) Lacking a blocking mechanism, the operator can forcibly start the machine by clicking "start", which cannot prevent human error. Summary of the Invention

[0004] This invention provides a temperature-controlled delayed start control method and device for extruders based on S7-300 PLC. It adds a temperature judgment and starts a timing mechanism after the temperature reaches the target. During the fixed delay period, it ignores external start signals through software-level blocking, which can effectively improve the safety and service life of the equipment.

[0005] According to one aspect of the present invention, a temperature-controlled delayed start control method for an extruder based on an S7-300 PLC is provided, wherein a stateless standard function block is pre-created in the S7-300 PLC, the method comprising:

[0006] The current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time are uploaded to the stateless standard function block.

[0007] The stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, the timer instance stored in the global data block is started to start timing.

[0008] When the timer instance reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder main motor.

[0009] Optionally, after starting the timer instance stored in the global data block to begin timing, the following also includes:

[0010] When the timing duration of the timer instance has not reached the fixed delay time, the stateless standard function block forces the motor operation signal output to the frequency converter to be set to FALSE.

[0011] Optionally, after determining whether the current actual temperature is greater than or equal to the process set temperature, the method further includes:

[0012] If the current actual temperature is less than the process set temperature, then reset the timer instance and temperature threshold latch stored in the global data block.

[0013] Optionally, the inputs of the stateless standard function block include the current actual temperature of type REAL, the process set temperature of type REAL, the external start request signal of type BOOL, and the fixed delay time of type TIME; the outputs of the stateless standard function block include the motor running signal of type BOOL and the status word in the delay of type BOOL.

[0014] Optionally, the global data block stores a BOOL-type temperature threshold latch, which is set when the current actual temperature first exceeds or equals the process set temperature.

[0015] Optionally, before uploading the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block, the following is also included:

[0016] Collect the current actual temperature of the extruder barrel.

[0017] Optionally, stateless standard function blocks do not occupy a separate background data block.

[0018] According to another aspect of the present invention, a temperature-controlled delayed start control device for an extruder based on an S7-300 PLC is provided, used to execute the temperature-controlled delayed start control method for an extruder based on an S7-300 PLC as described in any embodiment of the present invention. The device includes a stateless standard function block pre-created in the S7-300 PLC.

[0019] The data upload module is used to upload the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block.

[0020] A stateless standard function block control module is used to control the stateless standard function block to determine whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, a timer instance stored in the global data block is started to start timing.

[0021] The stateless standard function block control module is also used to control the stateless standard function block to respond to the external start request signal and start the extruder main motor when the timing duration of the timer instance reaches the fixed delay time.

[0022] Optionally, the device further includes a global data block storage module, which is used to store timer instances and temperature threshold latch bits.

[0023] Optionally, the device further includes a human-machine interface, which is used to set the process set temperature and fixed delay time, and to receive status words during the delay to display the equipment operating status.

[0024] The technical solution provided by this invention pre-creates a stateless standard function block in an S7-300 PLC. The current actual temperature of the extruder barrel, the process set temperature, the external start request signal, and a preset fixed delay time are uploaded to the stateless standard function block. The stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, a timer instance stored in the global data block is started to begin timing. When the timing duration of the timer instance reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder main motor. The technical solution provided by this invention can effectively improve equipment operating safety and service life.

[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart of a temperature-controlled delayed start control method for an extruder based on an S7-300 PLC is provided for an embodiment of the present invention;

[0028] Figure 2 A flowchart of another temperature-controlled delayed start control method for an extruder based on an S7-300 PLC provided in this embodiment of the invention;

[0029] Figure 3A schematic diagram of a temperature-controlled delayed start control device for an extruder based on an S7-300 PLC provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of an electronic device for an extruder temperature control delay start control method based on an S7-300 PLC, provided in an embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] Figure 1 This document presents a flowchart of a temperature-controlled delayed start control method for an extruder based on an S7-300 PLC, as provided in an embodiment of the present invention. This method can be executed by a temperature-controlled delayed start control device for an extruder based on an S7-300 PLC. This device can be implemented in hardware and / or software and can be configured in any electronic device with communication capabilities. See also... Figure 1 The method includes:

[0034] S110. Create a stateless standard function block in the S7-300 PLC in advance, and upload the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block.

[0035] Stateless standard function blocks (FCs) are one of the two core program encapsulation units in Siemens S7-300 / 400 series PLCs. Essentially, they are reusable code blocks without independent persistent storage, relying solely on input parameters to perform logical operations. In contrast, stateful function blocks (FBs) differ primarily in that FCs do not retain any internal data after execution, while FBs permanently save state across scan cycles using a dedicated background data block (Instance DB). Here, "state" specifically refers to data that needs to be continuously retained across multiple scan cycles of the PLC, such as timer remaining time, flag status, intermediate calculation results, and cumulative values. Pre-creation refers to the development, encapsulation, and testing of function blocks in the programming software before the PLC program is downloaded to the S7-300 CPU for execution, rather than dynamically generated during device runtime. The creation process is as follows: Create a new program block of type FC in the "Blocks" folder of the STEP7 project and name it "FC1_Heating Delay Start"; write complete control logic inside FC1, including all core code such as temperature comparison judgment, timer drive, software blocking execution, and output signal control; define standardized input and output interfaces for FC1, hide internal implementation details, and only expose external parameters that need to be interacted with; compile FC1 together with the main program organization block and global data block, and download it to the S7-300 CPU.

[0036] Here, uploading refers to the process by which the PLC main program organization block transmits four externally acquired or preset core parameters to the function block in real time through the input interface of FC1 during each cyclic call to FC1.

[0037] Specifically, the current actual temperature can be obtained through a temperature sensor, while the process set temperature, external start request signal, and preset fixed delay time can all be set through the human-machine interface. The process set temperature and fixed delay time can both be set via the human-machine interface based on empirical values.

[0038] All control logic is encapsulated within a stateless standard function block, enabling one-time writing and unlimited calls. Adding a new barrel segment simply requires repeatedly calling the stateless standard function block and passing in different temperature parameters. All variable data (current actual temperature, process set temperature, and fixed delay time) can be passed in through the interface. Subsequent modifications to process parameters do not require changes to the internal code of the stateless standard function block; adjustments can be made only in the HMI or global data block. With standardized interfaces, different extruder models and different PLC projects can directly reuse this stateless standard function block, significantly reducing engineering development and maintenance costs.

[0039] S120, the stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, the timer instance stored in the global data block is started to start counting.

[0040] Specifically, the S7-300 PLC's main program organization block OB1 runs in a loop with a fixed scan cycle (usually 1-10 milliseconds), and each loop completely calls the encapsulated stateless standard function block. During each call, the stateless standard function block first reads the latest data just passed in during the current loop—including the current actual temperature of the extruder barrel collected from the temperature sensor, and the preset process setting temperature read from the HMI or process database—and then performs a simple numerical comparison calculation internally.

[0041] It should be noted that, since the stateless standard function block itself does not retain any historical data, each judgment is based solely on the latest temperature value passed in the current scan cycle, and is not affected by the previous judgment result. If the current actual temperature is lower than the process set temperature, the stateless standard function block will directly execute the reset logic, clearing all subsequent delay-related states to zero, ensuring that the next step will only proceed after the temperature truly reaches the target. If the judgment result is that the current actual temperature is greater than or equal to the process set temperature, the stateless standard function block will trigger the subsequent timer start operation. This real-time cyclic judgment mechanism can effectively cope with temperature fluctuations during the heating process and avoid timer erroneous start due to brief temperature spikes.

[0042] Stateless standard function blocks do not have independent persistent storage. All temporary variables defined within them are only valid within the current call cycle. When the stateless standard function block finishes execution and returns to the main program, these temporary variables are immediately cleared by the PLC's local stack, and all data is lost. A timer, on the other hand, is a functional unit that needs to run continuously across multiple scan cycles. It needs to continuously accumulate time and save current timing values, running status, and other data. If a timer instance is defined inside a stateless standard function block, then after each call to the stateless standard function block, all the timer's states will be reset, making it impossible to complete delays lasting tens of minutes.

[0043] To resolve this contradiction, this solution pre-creates a dedicated global data block in the PLC, centrally storing all state data that needs to be retained across cycles. This includes the TON turn-on delay timer instance used for fixed delays. The global data block is an independent, permanently valid storage area in the PLC. As long as the PLC is running, the data stored in it will be retained and will not be lost due to the termination of any program block call. In this way, although stateless standard function blocks cannot save their own state, they can indirectly operate and manage the running state of timers by reading and writing the address of the global data block. This retains the low resource consumption advantage of stateless standard function blocks while also achieving cross-cycle delay functionality.

[0044] The term "startup" here does not refer to the stateless standard function block creating a new timer, but rather to the stateless standard function block modifying the trigger state of a timer instance in the global data block to start a predefined timer. The TON (On-Delay) timer in the S7-300 PLC has a core trigger input. When this input is set high, the timer begins accumulating time according to the PLC's system clock until the preset fixed delay time is reached. When the stateless standard function block determines that the temperature has reached the target, it writes a high-level signal to the trigger input of the corresponding TON timer instance in the global data block. From this moment on, the timer stored in the global data block begins timing independently.

[0045] During timer operation, even after the FC (Function Center) finishes execution and returns to the main program, the timer state in the global data block is completely preserved. When the FC is called again in the next scan cycle, it will continue to read the current timing value and output state of this timer. If the actual temperature of the extruder barrel drops below the process set temperature during timing, the FC will immediately set the timer's trigger input to a low level, and the timer will automatically reset and clear the current timing value until the temperature reaches the set temperature again before restarting timing.

[0046] The core technological significance of this step lies in establishing "temperature compliance" as a prerequisite for delayed start-up, completely eliminating the possibility of starting the equipment when the temperature does not meet the standard. Unlike existing technologies that rely solely on manual temperature judgment and allow for motor start-up at any time, this solution only begins calculating the fixed time required for material heat transfer after the temperature truly meets the process requirements. This provides an accurate triggering basis for subsequent software-level hard sealing, fundamentally solving the defect where the barrel surface temperature meets the standard but the internal material is not fully heated.

[0047] S130. When the timing duration of the timer instance reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder main motor.

[0048] Specifically, this solution uses the S7-300 PLC standard TON turn-on delay timer. This timer instance is completely stored in a pre-created global data block. As long as the PLC is running, it will independently accumulate time according to the system clock, unaffected by the end of the stateless function block call.

[0049] The S7-300 PLC's main program function block cyclically calls the stateless standard function block with a fixed scan cycle of 1-10 milliseconds. Each time it is called, the function block first accesses the global data block and reads the core output status bit of the TON timer. When the timer's duration is less than the preset fixed delay time, this status bit is always FALSE; when the duration is equal to or exceeds the fixed delay time, the status bit automatically changes to TRUE and remains in this state until the timer is reset.

[0050] It should be noted that this timing process is continuous and temperature-dependent: if the actual temperature of the extruder barrel drops below the process set temperature during the delay period, the stateless standard function block will immediately set the timer's trigger terminal to a low level. The timer will automatically reset all accumulated time and stop timing until the actual temperature reaches the set temperature again, at which point it will restart timing from zero. This ensures that the timer will only reach its timing endpoint if the barrel temperature remains at the set temperature and the material has completed sufficient heat conduction.

[0051] During the entire period before the timer finishes counting, the stateless standard function block executes an unavoidable forced blocking logic: regardless of whether a start request signal is sent externally or how the HMI interface is set, the function block will force the motor running signal output to the inverter to FALSE, which is equivalent to cutting off the main motor's start path from the program level.

[0052] This forced blocking logic will only be automatically lifted by the program when the stateless function block reads the timer's status bit in the global data block as TRUE. There are two strict conditions for "automatic lifting": First, the sole trigger for lifting is the timer completing its countdown; there are no other bypasses or backdoors. Second, the lifting process is entirely executed autonomously by the PLC program, requiring no manual confirmation or operation. Even if someone attempts to modify HMI parameters, bypass the HMI to send a start signal directly to the PLC input module, or even tamper with other code in the main program, they cannot lift this block prematurely because the blocking logic is completely encapsulated within the stateless function block; only the timer's state can control its on / off state.

[0053] After the block is lifted, the stateless standard function block will not automatically start the extruder's main motor. Instead, it will enter a "start allowed" standby state, at which point it will respond to externally received start request signals. This "response" is essentially a controlled signal pass-through: the function block will directly transmit the external start request signal received from the input interface to the motor operation signal terminal of the output interface without any further forced intervention.

[0054] The specific signal flow is as follows: When the operator presses the physical start button on the field control cabinet or clicks the virtual start button on the HMI (Human Machine Interface), this operation generates a Boolean high-level signal, which enters the main program function block through the PLC's digital input module. When the main program calls the stateless standard function block, it will pass this latest start request signal to the function block's input interface. After the function block internally determines that the software block has been released, it will directly assign the high-level signal from the input interface to the output interface. This output signal is sent to the frequency converter of the extruder's main motor through the PLC's digital output module. After receiving the running command, the frequency converter drives the main motor to start smoothly according to the preset speed curve.

[0055] This design avoids the safety risks caused by accidental automatic start-up of the equipment, while ensuring that the operator can only perform the start-up operation after the equipment meets the safe start-up conditions through a pre-set forced delay mechanism. It achieves comprehensive protection for the cold start process of the extruder from both technical and management perspectives.

[0056] The technical solution provided by this invention pre-creates a stateless standard function block in an S7-300 PLC. The current actual temperature of the extruder barrel, the process set temperature, the external start request signal, and a preset fixed delay time are uploaded to the stateless standard function block. The stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, a timer instance stored in the global data block is started to begin timing. When the timing duration of the timer instance reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder main motor. The technical solution provided by this invention can effectively improve equipment operating safety and service life.

[0057] Figure 2 This is a flowchart illustrating another temperature-controlled delayed start-up method for an extruder based on an S7-300 PLC, provided as an embodiment of the present invention. This embodiment further refines the aforementioned embodiments. See also... Figure 2 The method includes:

[0058] S210. Create a stateless standard function block in the S7-300 PLC in advance, and upload the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block.

[0059] This step is the same as the method step in the above embodiment S110, and will not be repeated here.

[0060] S220. Determine whether the current actual temperature is greater than or equal to the process set temperature; if yes, execute S230; if no, execute S240.

[0061] S230. Start the timer instance stored in the global data block to begin timing.

[0062] This step is the same as the method step in the above embodiment S120, and will not be described again here.

[0063] S240, Reset the timer instance and temperature threshold latch stored in the global data block.

[0064] Specifically, "Reset Timer Instance" refers to the stateless standard function block forcibly clearing all the status data of the TON turn-on delay timer stored in the global data block by reading and writing the address of the global data block. This includes: setting the cumulative count value of the timer to 0, setting the timer's run trigger terminal to low level, and clearing the timer's output status bit to FALSE.

[0065] This reset action is crucial for ensuring thermal balance: the accumulated time of the timer essentially represents the time it takes for the material to conduct internal heat after the actual temperature of the barrel reaches the set point. If the actual temperature drops below the process set temperature, it means that the barrel's metal wall and the internal material have begun to cool, rendering the previously accumulated holding time meaningless, and the material's temperature uniformity cannot be guaranteed. If the timer is not reset at this point, it will continue counting the remaining time after the temperature rises again, resulting in insufficient actual holding time. The material at the center of the screw may still be cold, and a huge torque impact will still occur during startup.

[0066] The temperature threshold latch is a Boolean flag stored in the global data block, specifically used to capture the rising edge of the actual temperature rising from below the process setpoint to above it. Without this latch, when the actual temperature fluctuates slightly around the process setpoint using PID control, frequent start-stop cycles would occur, with the timer starting when the current scan temperature reaches the setpoint and resetting when the next scan temperature is slightly lower. This would prevent the timer from completing the full 30-minute countdown. Therefore, when the temperature is first reached, the stateless standard function block sets this latch. Afterward, as long as the latch remains high, the timer will continue to operate normally even with brief, minor temperature fluctuations within the process-allowed range.

[0067] When the temperature actually falls below the process set temperature, this latch bit must be reset immediately. Its core purpose is to reset the edge detection state, ensuring that a complete delay cycle is triggered again when the temperature reaches the set point. If the latch bit is not reset, when the temperature rises above the process set temperature again, the function block will consider it a continuation of the previous temperature achievement and will not generate a new rising edge trigger signal. The timer will not restart from zero but will directly use the previous state, leading to severely insufficient holding time and complete failure of the protection logic.

[0068] This reset action forms a rigorous logical closed loop: the latch is only set when the temperature rises from low to high across the process set temperature, and it will be reset immediately as soon as the temperature falls from high to low below the process set temperature, ensuring that each delay is an independent and complete thermal equilibrium cycle, and there will be no superposition of timing across temperature fluctuations.

[0069] S250. Determine whether the timing duration has reached the fixed delay time; if yes, execute S260; if no, execute S270.

[0070] S260, a stateless standard function block, responds to an external start request signal to start the extruder's main motor.

[0071] S270, the stateless standard function block forces the motor running signal output to the frequency converter to be set to FALSE.

[0072] Specifically, the "forced" assignment here is not a regular signal assignment, but rather the final, non-overridable assignment operation of the motor operation signal within the stateless standard function block. In the program structure of the stateless standard function block, the assignment logic for the motor operation signal is strictly divided into two levels:

[0073] The first level is the normal startup logic: the motor running signal will only be set to TRUE when the timer finishes counting down and there is an external startup request;

[0074] The second level is the forced blocking logic: as long as the timer has not finished counting, regardless of the logic output of the first level, the function block will force the motor running signal to be rewritten to FALSE in the last step of the program.

[0075] The technical solution provided in this invention, unlike hardware delays, encapsulates tightly packed logic in a stateless standard function block. Even modifying the HMI value cannot bypass the block, eliminating human error and achieving software-level hardware protection. Compared to stateful standard function blocks, this stateless standard function block does not occupy a separate background data block, making it suitable for operation on resource-constrained older S7300 CPUs and saving storage space. This invention ensures internal and external thermal balance of materials through forced insulation, significantly reducing starting torque and preventing equipment overload, thereby protecting the screw and gearbox. This invention concentrates all control logic within a single stateless standard function block; subsequent modifications to delay parameters only require changing a single variable, eliminating the need to search the entire program, simplifying maintenance.

[0076] Optionally, the inputs of the stateless standard function block include the current actual temperature of type REAL, the process set temperature of type REAL, the external start request signal of type BOOL, and the fixed delay time of type TIME; the outputs of the stateless standard function block include the motor running signal of type BOOL and the status word in the delay of type BOOL.

[0077] Optionally, the global data block stores a BOOL-type temperature threshold latch, which is set when the current actual temperature first exceeds or equals the process set temperature.

[0078] Optionally, prior to S110, the following are also included:

[0079] Collect the current actual temperature of the extruder barrel.

[0080] Optionally, stateless standard function blocks do not occupy a separate background data block.

[0081] Figure 3 This is a schematic diagram of a temperature-controlled delayed start control device for an extruder based on an S7-300 PLC, provided in an embodiment of the present invention. A stateless standard function block is pre-created in the S7-300 PLC. (See also...) Figure 3 The device includes a data upload module 310 and a stateless standard function block control module 320.

[0082] The data upload module 310 is used to upload the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block.

[0083] The stateless standard function block control module 320 is used to control the stateless standard function block to determine whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, the timer instance stored in the global data block is started to start counting.

[0084] The stateless standard function block control module 320 is also used to control the stateless standard function block to respond to the external start request signal and start the extruder main motor when the timing duration of the timer instance reaches the fixed delay time.

[0085] The extruder temperature control delay start control device based on S7-300 PLC provided in this embodiment of the invention can execute the extruder temperature control delay start control method based on S7-300 PLC provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0086] Optionally, the device also includes a global data block storage module for storing timer instances and temperature threshold latch bits.

[0087] Optionally, the device also includes a human-machine interface (HMI) for setting the process set temperature and fixed delay time, and receiving status words during the delay to display the equipment's operating status.

[0088] The global data block storage module and the human-machine interface are not included. Figure 3 As shown in the image.

[0089] Figure 4 This is a schematic diagram of an electronic device for an extruder temperature control delay start control method based on an S7-300 PLC, provided as an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0090] like Figure 4As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 and a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, the ROM 12, and the RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0091] Multiple components in electronic device 10 are connected to input / output I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of monitors, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0092] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as a temperature-controlled delayed start control method for an extruder based on an S7-300 PLC.

[0093] In some embodiments, the S7-300 PLC-based extruder temperature control delay start control method can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via read-only memory ROM 12 and / or communication unit 19. When the computer program is loaded into random access memory RAM 13 and executed by processor 11, one or more steps of the S7-300 PLC-based extruder temperature control delay start control method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured in any other suitable manner to execute the S7-300 PLC-based extruder temperature control delay start control method.

[0094] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transferring data and instructions to the storage system, the at least one input device, and the at least one output device.

[0095] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0096] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0097] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device for displaying information to a user; and a keyboard and pointing device through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with a user; for example, feedback provided to the user can be any form of sensory feedback; and input from the user can be received in any form.

[0098] The systems and technologies described herein can be implemented in computing systems that include backend components, middleware components, or frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium. Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0099] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0100] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0101] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for temperature-controlled delayed start control of an extruder based on an S7-300 PLC, characterized in that, The method of pre-creating stateless standard function blocks in an S7-300 PLC includes: The current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time are uploaded to the stateless standard function block. The stateless standard function block determines whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, the timer instance stored in the global data block is started to start timing. When the timer instance reaches the fixed delay time, the stateless standard function block responds to the external start request signal and starts the extruder main motor.

2. The method according to claim 1, characterized in that, After starting the timer instance stored in the global data block to begin timing, the following is also included: When the timing duration of the timer instance has not reached the fixed delay time, the stateless standard function block forces the motor operation signal output to the frequency converter to be set to FALSE.

3. The method according to claim 1, characterized in that, After determining whether the current actual temperature is greater than or equal to the process set temperature, the method further includes: If the current actual temperature is less than the process set temperature, then reset the timer instance and temperature threshold latch stored in the global data block.

4. The method according to claim 1, characterized in that, The inputs of the stateless standard function block include the current actual temperature of type REAL, the process set temperature of type REAL, the external start request signal of type BOOL, and the fixed delay time of type TIME. The output of the stateless standard function block includes a BOOL type motor operation signal and a BOOL type delayed status word.

5. The method according to claim 1, characterized in that, The global data block stores a BOOL-type temperature threshold latch, which is set when the current actual temperature first exceeds or equals the process set temperature.

6. The method according to claim 1, characterized in that, Before uploading the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block, the following is also included: Collect the current actual temperature of the extruder barrel.

7. The method according to claim 1, characterized in that, Stateless standard function blocks do not occupy independent background data blocks.

8. A temperature-controlled delayed start control device for an extruder based on an S7-300 PLC, used to execute the temperature-controlled delayed start control method for an extruder based on an S7-300 PLC as described in any one of claims 1-7, characterized in that, The device includes a stateless standard function block pre-created in an S7-300 PLC, comprising: The data upload module is used to upload the current actual temperature of the extruder barrel, the process setting temperature, the external start request signal, and the preset fixed delay time to the stateless standard function block. A stateless standard function block control module is used to control the stateless standard function block to determine whether the current actual temperature is greater than or equal to the process set temperature. If the current actual temperature is greater than or equal to the process set temperature, a timer instance stored in the global data block is started to start timing. The stateless standard function block control module is also used to control the stateless standard function block to respond to the external start request signal and start the extruder main motor when the timing duration of the timer instance reaches the fixed delay time.

9. The apparatus according to claim 8, characterized in that, It also includes a global data block storage module, which is used to store timer instances and temperature threshold latch bits.

10. The apparatus according to claim 8, characterized in that, It also includes a human-machine interface, which is used to set the process set temperature and fixed delay time, and to receive status words during the delay to display the equipment operating status.

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