KR100254438B1 - Input and output communication device of general scan tool - Google Patents

Abstract

PURPOSE: An input and output communication device of a general scan tool is provided to implement a circuit satisfying a standard rule and cause a data transmitter to have both K line communication and failure output/signal output functions, thereby enabling using only 5 CPU ports. CONSTITUTION: A first pull-up resistor(R10) constantly maintains the level of signals output from a K line. A voltage divider(10) divides the voltage of the signals from the first pull-up resistor(R10). A constant voltage(20) stably maintains the signals of the voltage divider(10). A first comparator(30) compares the signals of the constant voltage(20) with a reference signal. A second pull-up resistor(R40) constantly maintains the voltage of the signals of the first comparator(30). A second comparator(40) compares the signals of the second pull-up resistor(R40) with a reference signal. A third pull-up resistor(R50) applies the signals of the second comparator(40) to a data transmitter. A circuit protector(50) protects the circuit from overcurrent and is switched by the signal of the data transmitter. An inverter(60) inverts the signals output from the data transmitter. A second voltage divider(80) divides the signals of a switch(70). First/second filters(C10,C30) remove external noise. A third filter(90) is connected between the constant voltage and the first comparator to remove noise in the signals.

Description

I / O device for general scan tool communication

The present invention relates to an input / output device for general scan tool (GST) communication, and more particularly, when the receiving end of the L line is in communication with the input / output circuit for the general scan tool (GST) communication included in the electronic control device, the " high " The present invention relates to an input / output device for GST communication that uses both a K line communication and a fault signal output for a data transmitting end of an electronic control device by using a characteristic of maintaining a " low "

In general, the communication between the electronic control device and the inspection device is to perform data communication through the communication cable line in accordance with the GST protocol.

The data communication is installed at an arbitrary position of the vehicle to detect the failure of the vehicle and receive the contents stored in the electronic control device as mutually promised data through the input / output device as shown in FIG. The user and the maintenance company can see the naked eye so that the maintenance of the correct trouble spot can be done easily.

However, in the conventional apparatus as shown in FIG. 2, communication-related circuits are configured using six CPU ports including a data transmitter, a data receiver, a receiver, and a fault signal transmitter, but do not partially satisfy the communication standard (ISO 9141-2). There was a problem.

The present invention has been made to solve such a problem, the object of the present invention is to implement a circuit that satisfies the communication standard, the characteristics of the L line, the receiving end of the electronic control device to maintain a "high" during communication, when the fault signal output By using "low", the data transmission end of the electronic control device combines K line communication and fault output signal output so that only five CPU ports can be used.

In order to achieve the above object, the present invention is a communication device between the inspection device and the electronic control device, the L line signal transmission unit and the K line, the receiving end holding a predetermined signal in accordance with the connector connection of the L line, First pull-up means connected to maintain a signal output through the K line at a constant potential, first voltage divider means connected to the first pull-up means to divide the potential of the signal of the first pull-up means, and the first A constant voltage means connected to the voltage dividing means to stably maintain the signal of the first voltage dividing means, first comparison means connected to the constant voltage means to compare the signal of the constant voltage means with a reference signal, and connected to the first comparison means; Second pull-up means for holding the signal of the first comparison means at a constant potential, second comparison means connected to the second pull-up means for comparing the signal of the second pull-up means with a reference signal; A third pull-up means connected to the second comparing means to maintain the signal of the second comparing means at a constant electric potential and applied to the data transmitting end, and one side is connected to the data transmitting end, and the other side is connected to the K line through the first pull-up means. Circuit protection means for protecting a circuit caused by the inflow of overcurrent and switching by a signal of a data transmitting end, signal inverting means connected to the data transmitting end and inverting a signal output from the data transmitting end, and connected to the signal inverting means A switching means switched by a signal of the inverting means, a second voltage dividing means connected to the switching means to divide the signal of the switching means, and one side is connected to the K line and the fault signal output terminal, respectively, and the other side is grounded to the case. First and third filter means for removing the noise flowing from the one side, the constant voltage means and the first comparison means on one side The other end is connected and the ground characterized by comprising a second filter means for removing noise of the signs,.

1 is a detailed circuit diagram illustrating an embodiment according to a general scan tool input / output device according to the present invention.

2 is a detailed circuit diagram showing a conventional input / output device for general scan tool communication.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

As can be seen in Figure 1 according to an embodiment of the present invention is an L line signal transmission unit (C1, C2, D1, D2, R1, R2, 1), the first pull-up resistor (R10), the first filter ( C10), the first voltage divider 10, the constant voltage unit 20, the second filter C30, the first comparator 30, the second pull-up resistor R40, the second comparator 40, and the third The pull-up resistor R50, the circuit protection unit 50, the inverter 60, the switch 70, the second voltage dividing unit 80, and the third filter 90.

One side of the L line signal transmission unit is grounded to the case of the GST device, and the other side is connected to the capacitor C1 connected to the checker L line, the anode end of which is connected to the diode D2, and the anode end of which is connected to the cathode of the diode D2. The cathode terminal is composed of a diode (D1) connected in parallel with the capacitor (C1) on the L line to maintain the output signal of the L line at a constant potential, the power terminal (V5) is connected to one side and the other side diode (D2) A pull-up resistor (R1) that is connected to the cathode end of the line and outputs a "high" signal when there is no connector on the L line, and a "low" signal when there is a connector on the L line. A capacitor C2 connected to the cathode terminal of the diode D2, which removes noise present in the signal of the pull-up resistor R1, an input terminal is connected to the other side of the capacitor C2, and an output terminal is connected through the resistor R2. To be connected to the reception terminal of the controller inverts the signal of the pull-up resistor (R1) comprises a drive (1) to be applied to the receiving end.

One end of the first pull-up resistor R10 is connected to the power supply terminal V1 to maintain the signal output through the checker device K line at a constant potential.

One end of the first filter C10 is grounded to a case of the GST device, and the other end thereof is connected to a K line to filter surge voltage or electromagnetic waves applied from the outside.

In the first voltage divider 10, a resistor R11 and a resistor R12 are connected in parallel, divide the potential of the signal output from the first pull-up resistor R10, and output an electrical signal accordingly.

In the constant voltage unit 20, a diode D21 having an anode terminal grounded and a diode D22 having a cathode terminal connected to a power terminal VI are connected in series so that the connection terminal of the diode D21 and the diode D22 is connected to the first terminal. It is connected to the first voltage dividing unit 10 and maintains the signal of the first voltage dividing unit 10 stably.

The second filter C30 is formed of a capacitor having one end grounded, and removes noise in a signal applied through the constant voltage unit 20.

The first comparator 30 has an inverting terminal connected to the constant voltage unit 20, and a non-inverting terminal connected to a voltage divider in which a resistor R33 and a resistor R34 are connected in parallel to a power supply terminal VI. The output terminal is connected to the output terminal through a connected pull-up resistor (R35), the + power terminal is grounded,-the power terminal is composed of an OP amplifier 31 connected in parallel with a capacitor (C32) to the power terminal (VI), the constant voltage The signal of the unit 20 is compared with the reference signal to output an electrical signal accordingly.

One end of the second pull-up resistor R40 is connected to the power supply terminal VI, and the signal of the first comparator 30 is maintained at a predetermined potential.

The second comparator 40 has an inverting terminal connected to the second pull-up resistor R40 through a resistor R42, and a non-inverting terminal is connected to a voltage divider in which a resistor R43 and a resistor R44 are connected in parallel. The stage is composed of an OP amplifier 41 connected to the output terminal through a pull-up resistor (R45) connected to the power supply terminal (V5), and compares the signal of the second pull-up resistor (R40) with a reference signal to thereby obtain an electrical signal accordingly. Output

One end of the third pull-up resistor R50 is connected to the power supply terminal V5, and the other end of the third pull-up resistor R50 is connected to the data transmission terminal of the K line, and the data transmission terminal maintains the signal of the second comparator 40 at a constant potential. To apply.

The circuit protection unit 50 includes a FET having a drain end connected to a connection point of the first pull-up resistor R10 and the first voltage divider 10, a base end connected to a source end of the FET, and a collector end connected to a FET. Is connected to the gate terminal of the emitter stage, the base stage and the emitter stage are connected to the resistor (R53), the collector stage and the emitter stage are connected to the resistor (R52) and the zener diode (ZD) to The transistor TR51 is connected to the data transmission terminal, and protects a circuit caused by the inflow of overcurrent, and is switched by a signal of the data transmission terminal to output a predetermined signal accordingly.

The inverter 60 inverts and outputs the signal output from the data transmission terminal of the K line.

The switch 70 includes a transistor having a base terminal connected to the inverter 60 through a resistor R73, an emitter terminal connected to a power supply terminal VI, and a base terminal and an emitter terminal connected to a resistor R72. TR71) and is switched by the signal of the inverter 60 to output a predetermined signal accordingly.

The second voltage dividing unit 80 is connected to the resistor R81 and the resistor R82 in parallel to be connected to the collector terminal of the transistor TR71, and divides the signal of the switch 70 and accordingly. Output a predetermined signal.

The third filter C90 has one end connected to the case C90 connected to the case, and the other end connected to the fault signal output, and removes various noises introduced into the signal of the second voltage divider 80. .

Referring to the embodiment of the present invention configured as described above in detail according to the operation process as follows.

During communication between the fault check device and the electronic control device, when a connector is connected to the check device L line and outputs a "low" signal, the receiving end of the electronic control device is operated by the operation of the pull-up resistor R1 and the inverter 1. If the signal "High" is maintained and the fault signal is output, and there is no connector connection to the check device L line, and the signal "High" is output, the pull-up resistor R1 and the inverter 1 operate to operate the receiving end of the electronic controller. Keeps the signal of "low".

When a connector is connected to the L line so that the receiving end of the electronic controller communicates by keeping the high, when the K line outputs a predetermined signal to transmit data, the first pull-up resistor R10 is connected to the K line. It keeps the signal output through the line at a constant potential.

At this time, the first filter C10 having one end grounded at the case of the GST device filters a surge voltage or an electromagnetic wave applied from the outside.

Thereafter, when the first voltage divider 10 divides the potential of the signal output from the first pull-up resistor R10 and outputs an electrical signal accordingly, the constant voltage unit 20 receives the signal of the first voltage divider 10. Keep it stable.

Then, the second filter C30 removes noise in the signal of the first voltage dividing unit 10.

The first comparator 30 compares the signal of the constant voltage unit 20 from which the noise is removed from the second filter C2 with a reference signal, and outputs an electrical signal according to the second pull-up resistor R40. The signal of the first comparator 30 is maintained at a constant potential and applied to the second comparator 40.

At this time, the second comparator 40 compares the signal of the second pull-up resistor R40 applied through the resistor R42 with a reference signal and outputs an electrical signal according to the third pull-up resistor R50. It is maintained at a constant potential and applied to the data transmission end.

In contrast to the above, when the K line receives data, when a predetermined signal is output from the data transmitter, the FET of the circuit protection unit 50 is switched on. As the FET is switched on, the high potential is induced in the base of the transistor TR51 by the power supply VI through the first pull-up resistor R10, and the transistor TR51 is also switched on.

Then, the signal output from the circuit protection unit 50 is maintained at a constant potential through the first pull-up resistor R10 and applied to the K line to receive data.

However, when there is no connector connection on the L line and the receiving end keeps " low " and outputs a failure signal, the inverter 60 outputs the inverted signal output from the data transmitting end.

At this time, when the transistor TR71 of the switch 70 is switched by the signal of the inverter 60 and outputs a predetermined signal according thereto, the signal of the switch 70 is divided by the second voltage dividing unit 80. External inflow noise is prevented by the third filter C90 so that the signal of the data transmission end is output through the failure signal output end.

As described above, the present invention satisfies the communication standard, and uses the receiving end characteristics of the L line to maintain "high" during communication and "low" when outputting a fault signal, so that the K line communication and fault signal output is performed only by the data transmitting end. In addition, the two ports of the conventional data transmitter and the fault signal transmitter are formed as one port so that only five ports of the CPU can be used.

Claims (5)

A device for communication between a check device and an electronic control device, comprising: an L line signal transmission unit for receiving a predetermined signal by a receiving end according to a connector connection of an L line, and a signal output through a K line by connecting a K line to a predetermined potential; A first pull-up means connected to the first pull-up means to divide the potential of the signal of the first pull-up means, and a first pull-up means connected to the first pull-up means, A constant voltage means for maintaining a stable state, first comparing means connected to said constant voltage means for comparing a signal of said constant voltage means with a reference signal, and connected to said first comparing means for maintaining a signal of said first comparing means at a constant potential; A second pull-up means, second comparison means connected to the second pull-up means for comparing a signal of the second pull-up means with a reference signal, and a second comparison means connected to the second comparison means. And a third pull-up means for applying to the data transmitter at a constant potential, and one side connected to the data transmitter and the other side to a K line through the first pull-up means to protect the circuit caused by the inflow of overcurrent and Circuit protection means switched by the switching means, signal inversion means connected to the data transmission end to invert the signal output from the data transmission end, switching means connected to the signal inversion means and switched by the signal of the signal inversion means, and the switching. Second dividing means connected to the means for dividing the signal of the switching means, and first and third filter means each having one side connected to the K line and the fault signal output terminal and the other side being grounded to the case to remove noise from the outside; And one side is connected between the constant voltage means and the first comparing means and the other side is grounded so that the noise in the signal The general scan tool communication input and output device, characterized in that comprises a second filter means for removing. The method according to claim 1, wherein the constant voltage means is connected to the diode (D21) of the anode terminal is connected to the diode (D22) connected in parallel with the cathode terminal is connected to the power source (VI) in parallel, the connection terminal of the diode (D21) and diode (D22) An input / output device for general scan tool communication, characterized in that connected to the first voltage dividing means. The method of claim 1, wherein the first comparison means, the inverting terminal is connected to the constant voltage means, the non-inverting terminal is connected to the power supply terminal (VI) and the voltage divider connected in parallel with the resistor (R33) and the resistor (R34) Input and output devices connected to the output terminal via a connected pull-up means, + power terminal is grounded,-power supply terminal is an input / output device for general scan tool communication, characterized in that the power terminal (VI) consisting of an OP amplifier connected in parallel with the capacitor (C32) . The method according to claim 1, wherein the second comparison means, the inverting terminal is connected to the second pull-up means through the resistor (R42), the non-inverting terminal is one side with the voltage dividing means connected in parallel with the resistor (R43) and the resistor (R44) Input / output device for general scan tool communication, characterized in that the stage is made of an OP amplifier connected to the output terminal through a pull-up means connected to the power supply terminal (V5). 2. The circuit protection means according to claim 1, wherein the circuit protection means includes a FET having a drain end connected to a connection point of the first pull-up means and a first voltage divider, a base end connected to a source end of the FET, and a collector end connected to a gate end of the FET. Transistor connected to ground, the emitter stage connected to a resistor (R53), the collector stage and emitter stage connected to a resistor (R52) and a zener diode (ZD), and connected to a data transmission stage. An input / output device for general scan tool communication, comprising (TR51).