JPH02262797A - Communication equipment for vehicle - Google Patents

Abstract

PURPOSE:To prevent the erroneous response due to another not selected controller and to surely communicate with a selected controller by continuously transmitting an initializing command to each controller at prescribed intervals by the number of times corresponding to the number of information signals transmitted following a control command. CONSTITUTION:A master station 9 selects desired one of plural controllers 1 and 3 and transmits various commands for various diagnosis and information bytes to the selected controller and receives an echo back signal as the response signal from the controller to perform diagnosis. In this case, the master station 9 continuously transmits an initializing command INIT twice at a prescribed interval for the purpose of initializing lines and closing a link. That is, the initializing command is transmitted twice at the time of transmitting two information signals; and though both of two information signals have the same information as the initializing command, the erroneous response of another not selected controller is prevented because the next command is certainly different from a system select command.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a control device such as a vehicle engine control unit, and a device such as a master station for diagnosing this control device. The present invention relates to a vehicle communication device that performs communication between vehicles.

(Prior Art) In recent years, with the advancement of semiconductor technology, the electronic control of various parts of automobiles has progressed rapidly, and many microprocessors are installed in electronic control units (ECUs) such as engine control units.
is used as.

Although these highly electronically controlled systems realize high-performance and comfortable vehicles, they also complicate failure diagnosis. This process involves complex electronic processing of a large number of input signals, making it difficult to understand the causal relationship between the phenomena that occur and the causes, and requires advanced knowledge to analyze.
This is also because intermittent interruptions in minute electrical signals are easily affected by external noise.

For this reason, many electronic control units are equipped with a self-diagnosis function, but since this diagnosis is an on-board diagnosis, processing capacity is limited. A master station that constitutes a board diagnostic device is being developed.

When diagnosing each electronic control unit of a vehicle using such a master station, the master station selects the desired electronic control unit to be diagnosed from among multiple electronic control units, and performs diagnostic tests on the selected electronic control unit. Data communication is performed by transmitting a control command and receiving reply data from the electronic control unit in response to the control command.

In such data communication, the master station initializes the communication line with each electronic control unit and waits to receive a system selection command to select a desired electronic control unit from among multiple electronic control units. An initialization command for setting each electronic control unit is sent to each electronic control unit. After transmitting this initialization command, the communication line is initialized, and each electronic control unit is set to a standby state for receiving a system selection command, the master station transmits the system selection command and selects the desired electronic control unit. Select only the control unit and establish a data link with this selected electronic control unit.

Once the data link between the master station and the selected electronic control unit is established, the master station sends a control command, such as a parameter set command, to the selected electronic control unit to perform a desired control operation. At the same time, following the control command, two information bytes related to the control command are successively transmitted at a predetermined interval, so that, for example, the first information byte sets the item to be controlled, and the second information byte sets the item to be controlled. The information byte sets the control amount, etc. Then, the response performance of the vehicle, specifically the engine, etc., with respect to the conditions set in this way is monitored, and diagnosis is performed based on this.

(Problem to be Solved by the Invention) As described above, in the communication between the master station and the electronic control unit, the mask station only sends an initialization command once to each electronic control unit; After the data link between the master station and the selected electronic control unit has been established, if the master station sends two information bytes following the selected control command sent to the electronic control unit, these two The first information byte of the two information bytes is the same information as the initialization command, and the second information byte is the same information as the system selection command for other electronic control units other than the selected electronic control unit. In this case, there is a problem in that other electronic control units, that is, unselected electronic control units, erroneously respond to the initialization command consisting of the first information byte and the system selection command consisting of the second information byte. More specifically, there is a problem in that the echo back signal from the other electronic control unit due to this erroneous response destroys the echo back signal from the normal electronic control unit, making correct communication impossible.

The present invention has been made in view of the above, and its purpose is to prevent erroneous responses from other control devices that are not selected, and to accurately communicate only with the selected control device. The object of the present invention is to provide a vehicle communication device that can perform the following functions.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the vehicle communication device of the present invention has the following features:
A desired control device is selected from among the plurality of control devices, and a control command is sent to the selected control device to perform a predetermined control operation. A vehicle communication device that transmits one or more information signals to the selected control device, the communication device initializing a communication line with the plurality of control devices, and initializing the communication line with the plurality of control devices. an initialization command that sets each control device to a standby state for receiving a selection command for selecting a desired control device, and sends an initialization command to each control device consecutively at a predetermined interval corresponding to the number of the information signals; The gist is to have a transmission means.

(Operation) In the vehicle communication device of the present invention, a number of initialization commands corresponding to the number of information signals transmitted following the control command are successively transmitted to each control device at predetermined intervals.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing the system configuration of a vehicle communication device according to an embodiment of the present invention. In the embodiment shown in the figure, a plurality of control devices 1, 3.・・・
are connected to each other by a signal line 5 consisting of a data transmission line TX, a data reception line Rx, and a clock line CLK, and a master station 9 is connected to these control devices via the signal line 5 and a connector 7. .

This master station 9 constitutes an off-board diagnostic device for diagnosing the control section of the vehicle, which is composed of the plurality of control devices 1.3, for example, and includes a numeric keypad 11 for inputting various information, a display for displaying diagnostic information, etc. 13, a power switch 15, an end key 17 for ending the diagnostic operation, and the like. Although FIG. 1 only shows two control devices, the first and second control devices 1.3, the present invention is not limited to this, and various other control devices may be provided. It is something that

The master station 9 has a plurality of control devices 1 and 3.
Select a desired one of them, send various commands to the selected control device in order to diagnose the control device, obtain response information to this command from the control device, and use this response information to control the control device. We are conducting a diagnosis.

In this way, the master station 9 sends various commands to each control device in order to diagnose each control device, and in data communication between the two to obtain response information, the transmission line code type, so-called data modulation method, is used. is N
Using the RZ method and UART as the communication circuit,
As shown in Figure 2, the data format used is one in which a start bit is added at the beginning, then 8-bit data is inserted, and a stop bit is added at the end, and this is used for each communication. Consists of commands and information bytes. Furthermore, the transmission control method between the master station 9 and each control device employs a polling selection method in which the master station 9 is a master station and each control device is a slave station.

Moreover, the master station 9 uses the above-mentioned modulation method,
A desired control device is selected from among the plurality of control devices 1.3 based on the transmission control method, etc., and various commands and information bytes for performing various diagnoses are sent to the selected control device, and responses are sent to the selected control device. The echo pack signal, which is a signal, is received from the control device and diagnosis is performed using this signal.The control procedure for this selection and diagnosis is divided into four phases 0 to 3 as shown in the table below. There is.

Next, the operation will be explained with reference to a table showing these phases, a timing chart shown in FIG. 3, and an operation table for changing the engine speed shown in FIG. 4. Note that each phase 0 to 3 defined in the above table showing the phases is shown on the horizontal time axis of the timing chart in FIG. 3, and the control procedure by the master station 9 is executed sequentially according to these phases. It has become.

≠The master station 9 controls each control device 1.
3, connect the master station 9 and each control device 1, 3 using the connector 7 as described at the beginning of the item "Person (operation)" in FIG. Turn on the power and put it into operation.

The initialization command is a command that targets all control devices, but if echo packs, which are response signals, are returned from multiple control devices, there is a risk that the master station will not be able to read the echo back data. If there is a controller, only the controller establishing this link returns the echo pack.

When the power is turned on in this way and the master station 9 enters the operating state, the master station 9 enters the state of phase 0, and the display 13 of the master station 9 shows the fourth
As shown at 41 in the figure, all the control devices currently connected to the master station 9, such as "1, first control device", "2° second control device", etc., are displayed. In addition, in this phase 0, the master station 9 initializes the line and terminates the link.
As shown at times t1 and t2 in FIG. 3, the initialization command INIT is transmitted twice consecutively at a predetermined interval. When each control device 1.3 receives this initialization command, each control device 1, 3 enters a waiting state for receiving a system selection command, which will be described later, and the signal line 5, especially the data transmission line Tx of the signal line 5, is The line made up of the signal line 5 is then initialized. Furthermore, if there is a control device that is establishing a data link at this time, this control device terminates communication and similarly enters a state of waiting to receive a system selection command.

As described above, when the line consisting of the signal line 5 is initialized and each control device 1, 3 enters the state of waiting to receive a system selection command, the master station 9 enters the phase 1 state, but in this state, the operator is a plurality of control devices 1.3
In order to select a desired control device to be diagnosed, use the numeric keypad 11 of the master station 9 to select the number of the desired control device, and perform one-on-one communication with the control device with the selected number. The corresponding system selection command 5C(1) is transmitted as shown at time t3 in FIG.

Note that this figure shows a case where the first control device 1 is selected, and a system selection command 5C(1) is transmitted.

When the system selection command 5C(1) sent from the master station 9 is received by the selected first control device 1, this first control device 1 sends a command to notify the master station 9 of the reception. An echo back signal 5C(1) obtained by inverting the system selection command 5C(1) is sent back to the master station 9 as shown at time t4 in FIG.

When the master station 9 receives this inverted echo disparity signal 5C(i) and confirms that this inverted echo pack signal is from the selected first control device 1, the master station 9 and this first A data link is established with the control device 1 of the controller. Note that other control devices, such as the second control device 3, which are not selected at this time return to the initialization command waiting state, and maintain this state until the next initialization command is received twice. Therefore, only the selected first control device 1 that is establishing a data link can communicate with the master station 9.

Once the first control device 1 has been selected in this way and the data link between this first control device 1 and the master station 9 has been established, the master station 9 enters phase 2 and enters the diagnostic mode. You will have to set
In this state, a list of diagnostic functions that can be executed by the master station 9 is displayed on the display 13 of the master station 9, as shown at 42 in FIG.

In order to set the diagnostic mode in this phase 2,
The master station 9 sends a mode setting command, and there are various commands in this mode setting command, and they can be roughly divided into commands that are independently defined, and control commands that have information bytes following the command, such as a parameter set command Ps. There is a command.

The parameter set command PS is a command that instructs to set, for example, the state of the engine to a specific state, and following this command, for example, two information bytes are successively transmitted at a predetermined interval. ing. For example, if you want to set the engine's idling speed to 1500 rpm, use this parameter command PS
Subsequently, a first information byte indicating "engine idling rotation speed" and a second information byte indicating "r1500 rotations" may be transmitted.

Therefore, the operator now selects the case where the engine idling speed is set to 1500 revolutions as described above as the diagnosis mode, and the master station 9
When the diagnostic mode for the parameter set command is selected from the display 13 of the master station 9 using the numeric keypad 11, and "number of revolutions" and "r1500 revolutions" are specified using the numeric keypad 11 as information bytes for this parameter set command PS, the display 1 of the master station 9
3 contains the "rotation speed" and r1 as shown at 43 in Figure 4.
500 revolutions" is displayed, and then a parameter set command PS is transmitted from the master station 9 to the first control device 1 as shown at time t5 in FIG.

When the first control device 1 receives the parameter set command PS from the master station 9, the first control device 1 returns an echo back signal PS, which is an inverted version of the parameter set command PS, to the master station 9 to confirm reception. At time t6), the device enters a state of waiting for an information byte. When the master station 9 confirms that the inverted echo back signal from the first control device 1 is the inverted data of the previously transmitted parameter set command PS,
A first information byte 1 tem indicating the rotational speed is transmitted to the first control device 1 as shown at time t7 in FIG. When the first control device 1 receives this first information byte I tem, it returns an echo back signal of the same data as this first information byte, that is, an echo back signal that is not inverted, to the master station 9 (the third Figure time t8)
. When the master station 9 verifies that the echoback signal from the first control device 1 is the same as the first information byte sent earlier, the master station 9 transmits a second information byte indicating "r1500 revolutions". 1 (time t9 in FIG. 3). When the first control device 1 receives this second information byte Item, it
An echo back signal of the same data as the information byte I terA is sent back to the master station 9 (at time t in Figure 3).
10). The master station 9 is the first control device 1
It is confirmed that the echo back signal from the I-- Teffl is the same as the second information byte I teffl sent earlier, and the setting of the parameter set command PS is completed. Since the information byte represents many items, control values, etc., any value can be taken within the specified byte.

When the master station 9 finishes setting the diagnostic mode using the parameter set command PS as described above, it enters phase 3 and sends the diagnostic execution command EX to the first control device 1 as shown at time tll in FIG. . When the first control device 1 receives the diagnosis execution command EX from the master station 9, it selects the control values of the control items previously set by the parameter set command PS, that is, in the case described above, the "engine speed" and r15.
Execution is performed for a control value such as "00 revolutions", and the diagnostic data of the engine rotation speed data at the time of this execution is repeatedly returned until a diagnostic end command STP is sent from the first control device 1 to the master station 9. . It should be noted that the diagnostic data returned in this way is transmitted at time t in FIG.
12. ~ As shown in t13, a single file consisting of a 1-byte header, 1-byte data length, and 254-byte or less data
It will be returned as one frame.

The diagnostic data returned from the first control device 1 is received by the master station 9, and the received diagnostic data is displayed on the display 13 of the master station 9 on the fourth
The screen is displayed as shown in the figure, confirming that the control values have been changed as specified and that the engine relationship is normal. In the example shown in FIG. 4, the engine speed of the diagnostic data displayed on the display 13 of the master station 9 is 1.
It turns out to be 502 rotations, which indicates that it is almost normal.

When the diagnostic data is obtained as described above, the operator presses the end key 17 of the master station 9. End key 1
7 is pressed, the master station 9 transmits a diagnosis end command STP to the first control device 1 (time t14 in FIG. 3). The first control device 1 sends a diagnosis end command S
When TP is received, the control command settings that have been set so far are cleared, and an echo back signal STP, which is the inverted data of the received diagnostic end command STP, is sent back to the master station 9 (at time t1 in FIG. 3).
5). When the master station 9 receives the inverted echo pack signal STP from the first control device 1, it thereby ends the diagnosis for the first control signal 1.

Note that in the above embodiment, two information bytes are sent and the initialization command is sent twice to correspond to this, but the invention is not limited to this, and the information bytes can be up to 3.
In the case of bytes, the initialization command may also be transmitted three times in succession.

In other words, it is sufficient to transmit a number of initialization commands corresponding to the number of information bytes.

[Effects of the Invention] As explained above, according to the present invention, initialization commands of a number equivalent to the number of information signals transmitted following a control command are successively transmitted to each control device at predetermined intervals. Therefore, for example, when transmitting two information signals,
The initialization command will be sent twice, but even if both of the two information signals have the same information as the initialization command, the next command will always have a different code from the system selection command. , other unselected control devices will not respond erroneously, and therefore normal communication can always be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a system configuration of a vehicle communication device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a data format used in the vehicle communication device of FIG.
FIG. 3 is a timing chart showing the operation of the vehicle communication device shown in FIG. 1, and FIG. 4 is a table showing the operation and effects of the vehicle communication device shown in FIG. 1...First control device 3...Second control device 5...Signal line 9...Master station 11...Numeric keypad 13...Display 17...End key

Claims (1)

[Claims] A desired control device is selected from among the plurality of control devices, and a control command is sent to the selected control device to perform a predetermined control operation. A vehicle communication device that transmits one or more information signals to the selected control device, the communication device initializing a communication line with the plurality of control devices, and initializing the communication line with the plurality of control devices. Sending an initialization command to successively send an initialization command to each control device at predetermined intervals corresponding to the number of information signals to set each control device in a state of waiting to receive a selection command for selecting a desired control device; A vehicle communication device characterized by having a means.