PLC single-ended wiring digital quantity output module

Abstract

The utility model aims to provide the PLC single-ended wiring digital quantity output module which is simpler in circuit structure, low in cost and better in reliability. The circuit comprises an EtherCAT ASIC unit, a plurality of photoelectric couplers and an integrated low-side switch, the EtherCAT ASIC unit is communicated with an external control end, control ends of the photoelectric couplers are connected with an IO port of the EtherCAT ASIC unit, output ends of controlled ends of the photoelectric couplers are correspondingly connected to an input end of the integrated low-side switch, and the integrated low-side switch is connected with an output end of the EtherCAT ASIC unit. And the output end of the integrated low-side open switch is connected with a load to be controlled. The utility model is applied to the technical field of the PLC control IO module.

Description

Technical Field

[0001] The utility model is applied to the technical field of PLC control IO modules, and particularly relates to a PLC single-end wiring digital quantity output module. Background Art

[0002] With the development of technology, circuit control is converted from analog signal drive components to digital signal control, which can realize remote control and ensure the transmission reliability of control signals. The output of existing PLC digital control units is usually to control resistors, inductors, lamp loads, etc. The conventional PLC digital control structure consists of: Scheme 1, EtherCAT chip + MCU + optoelectronic isolator + separate low-side switch; Scheme 2: ethercat chip + MCU + capacitor isolator + separate low-side switch. Both Scheme 1 and Scheme 2 use separate low-side switches and draw power from external loads through current circuits and overvoltage detection circuits. Therefore, it is necessary to design current limiting circuits and overvoltage detection circuits for each independent channel to ensure the reliability of the control circuit operation, which requires adding more components and taking up more space in the controller. Among them, although Scheme 2 uses fast and highly integrated capacitor isolators, it replaces fewer chips and has a higher cost.

[0003] If a PLC single-ended wiring digital output module with a simpler circuit structure, lower cost and better reliability can be provided, the above problems can be well solved. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a PLC single-ended wiring digital output module with simpler circuit structure, lower cost and better reliability.

[0005] The technical solution adopted by the utility model is: the utility model includes an EtherCAT ASIC unit, a plurality of photoelectric couplers and an integrated low-side switch, the EtherCAT ASIC unit communicates with an external control end, the control ends of the plurality of photoelectric couplers are connected to the IO ports of the EtherCAT ASIC unit, the controlled end outputs of the plurality of photoelectric couplers are correspondingly connected to the input end of the integrated low-side switch, and the output end of the integrated low-side switch is connected to a load to be controlled.

[0006] It can be seen from the above scheme that the EtherCAT ASIC unit is connected to the external control end, and then receives the control signal and transmits the control signal through a number of photocouplers, and the integrated low-side switch controls multiple drive signals and connects the load for driving. Among them, the photocoupler is driven by the EtherCAT ASIC unit to avoid MCU transfer, and the photocoupler is independently powered instead of being powered by the power supply of the external load through the current limiting circuit and the overvoltage detection circuit, thereby reducing the overall use of components. Effectively reduce costs, while the external control end PLC control device communicates through Ethernet and directly controls the digital input and output IO port for control, thereby improving the response speed. The photocoupler is used as the isolation device between the EtherCAT ASIC unit and the integrated low-side switch, and there are many isolator models to choose from, which reduces the difficulty of procurement.

[0007] A preferred solution is that the integrated low-side switch includes a driver chip of model DRV8803PWPR, and a reverse protection diode is connected between the VM port and the VCLAMP port of the driver chip.

[0008] A preferred solution is that the output end of the integrated low-side switch is connected to the load to be controlled through a magnetic bead.

[0009] A preferred solution is that an RC filter component is provided between the control end of the photoelectric coupler and the IO port of the EtherCAT ASIC unit.

[0010] A preferred solution is that the utility model further comprises a power supply unit, wherein the power supply unit comprises a step-down chip, and the step-down chip converts the input voltage into a 5V DC voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a system connection block diagram of the utility model;

[0012] Figure 2 is a circuit schematic diagram of the EtherCAT ASIC unit;

[0013] Figure 3 is a circuit schematic diagram of the optocoupler and the integrated low-side switch;

[0014] Figure 4 is a circuit schematic diagram of the power supply unit. DETAILED DESCRIPTION

[0015] like Figure 1As shown, in this embodiment, the utility model includes an EtherCAT ASIC unit 1, a plurality of photocouplers 2 and an integrated low-side switch 3, the EtherCAT ASIC unit 1 communicates with an external control end, the control ends of the plurality of photocouplers 2 are connected to the IO ports of the EtherCAT ASIC unit 1, the controlled end outputs of the plurality of photocouplers 2 are correspondingly connected to the input ends of the integrated low-side switch 3, and the output end of the integrated low-side switch 3 is connected to the load to be controlled.

[0016] like Figure 2 As shown, the EtherCAT ASIC unit 1 includes an Ethernet transceiver U701A / U701B of model LAN9253-I / R4X, and the Ethernet transceiver U701A / U701B performs industrial Ethernet EtherCAT protocol communication and has sixteen digital input and output IO ports. The sixteen digital input and output IO ports are used by several of the optocouplers 2 to control the integrated low-side switch 3.

[0017] like Figure 3 As shown, in this embodiment, the integrated low-side switch 3 includes a driver chip U903 of model DRV8803PWPR, and a reverse protection diode D902 is connected between the VM port and the VCLAMP port of the driver chip U903. The reverse protection diode D902 prevents overvoltage from being injected into the power supply unit 4. The output end of the integrated low-side switch 3 is connected to the load to be controlled through a magnetic bead. The DRV8803PWPR chip of TI company is used as the low-side switch. The chip has undervoltage protection, overheat protection, and overcurrent protection capabilities, and has a larger current carrying capacity than transistors.

[0018] In this embodiment, an RC filter component is provided between the control end of the photocoupler 2 and the IO port of the EtherCAT ASIC unit 1. The RC filter component includes a resistor and a capacitor, wherein the resistor is connected in series between the IO port of the EtherCAT ASIC unit 1 and the control input end of the photocoupler 2, and the capacitor is connected in parallel between the control input end and the control output end of the photocoupler 2, and the control output end of the photocoupler 2 is grounded. The RC filter component is used to filter out the unexpected burr voltage output by the EtherCAT ASIC unit 1. A status light is connected to the controlled output end of the photocoupler 2 to confirm the input state and the output state. The model of the photocoupler 2 is EL3H7(B)(TA)-G.

[0019] In this embodiment, the utility model also includes a power supply unit 4, and the power supply unit 4 includes a step-down chip U603. The step-down chip U603 converts the input 24V DC voltage into a 5V DC voltage and outputs it to the controlled end of the photocoupler 2. On the one hand, the power supply unit 4 provides the photocoupler 2 with the necessary voltage and current to drive the low-side switch and the light-emitting diode. On the other hand, by using the internal power supply solution, digital output can be achieved without the need for external COM power connection, and a single-line connection can be achieved. By using the DC / DC solution, the power supply efficiency can be improved and heat generation can be reduced. The model of the step-down chip U603 is SY8401ABC.

[0020] Although the embodiments of the present invention are described with practical solutions, they do not constitute limitations on the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A PLC single-ended wiring digital output module, characterized in that: It comprises an EtherCAT ASIC unit (1), a plurality of photoelectric couplers (2) and an integrated low-side switch (3), wherein the EtherCAT ASIC unit (1) communicates with an external control end, the control ends of the plurality of photoelectric couplers (2) are connected to an IO port of the EtherCAT ASIC unit (1), the controlled end outputs of the plurality of photoelectric couplers (2) are correspondingly connected to the input end of the integrated low-side switch (3), and the output end of the integrated low-side switch (3) is connected to a load to be controlled.

2. A PLC single-ended wiring digital output module according to claim 1, characterized in that: The integrated low-side switch (3) comprises a driver chip (U903) of model DRV8803PWPR, and a reverse protection diode (D902) is connected between a VM port and a VCLAMP port of the driver chip (U903).

3. A PLC single-ended wiring digital output module according to claim 1, characterized in that: The output end of the integrated low-side switch (3) is connected to a load to be controlled via a magnetic bead.

4. A PLC single-ended wiring digital output module according to claim 1, characterized in that: An RC filter component is provided between the control end of the photoelectric coupler (2) and the IO port of the EtherCAT ASIC unit (1).

5. A PLC single-ended wiring digital output module according to claim 1, characterized in that: It also includes a power supply unit (4), wherein the power supply unit (4) includes a step-down chip (U603), and the step-down chip (U603) converts the input voltage into a 5V direct current voltage.

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