JP5504453B2 - Subordinate apparatus and information processing system - Google Patents

Description

  The present invention relates to a lower-level device and an information processing system that transmit a current state and a processing result to a higher-level device.

  Conventionally, magnetic information such as unique information is recorded on a magnetic stripe formed on a card-like medium such as a credit card, prepaid card, or cash card. Magnetic card readers are widely used to read or write magnetic information. Hereinafter, this magnetic card reader will be described as an example of a lower-level device.

This magnetic card reader (lower device) communicates with the host device and executes processing according to the situation to transmit the current state and processing result to the host device. For example, in a swipe-type magnetic card reader, when a card-like medium is read (for example, when a user manually runs (swipes) a card), reset due to static electricity (reset of the magnetic card reader device) occurs. There is a case. As a countermeasure in such a case, like the magnetic card reader disclosed in Patent Document 1, for example, it waits until a predetermined reset signal is received from the host device, and when this is received, it returns to the initial state. There are measures.
In addition, although the probability is lower than the reset by static electricity, the CPU may run away for some reason. In this case, communication cannot be performed with the host device, and the host device is in an uncontrollable state with respect to the magnetic card reader. As a countermeasure, a measure is taken such that the user turns off the power supply of the host device and then turns it on again to restore.

Japanese Patent Laid-Open No. 2-96297

  However, when the CPU of the magnetic card reader runs out of control, for example, when it enters a mode that cannot be restored by a normal reset, the host device must be turned on again as described above. Imposing on the user is not convenient.

  For example, when considering a self-service system (such as a POS system at a gas station) that operates continuously for 24 hours and is operated by the customer, it is in a state where it is not known what kind of operation is performed by an unspecified number of people. If a CPU runaway occurs during the operation, the possibility of an appropriate ON / OFF operation is low. Also, when considering such a system, since it is required to continue to operate without stopping in any situation, even if the store clerk can be restored by turning the host device on and off The intervention of artificial ON / OFF operation is not preferable.

  The present invention has been made in view of these points, and its purpose is to enable automatic recovery even when the CPU of the lower-level device has runaway, improving convenience. It is an object of the present invention to provide a subordinate device and an information processing system that can be used.

  In order to solve the above problems, the present invention provides the following.

(1) A lower-level device that communicates with a higher-level device and executes processing according to the situation and transmits the current state and processing result to the higher-level device, and communicates with the higher-level device. Interface for receiving the RTS signal of the higher-level device and transmitting the CTS signal, the main control unit for controlling the operation of the lower-level device to execute the processing according to the situation, and the main control unit runaway A power control unit that controls power supply to the main control unit based on a CTS signal transmitted from the communication interface , the power control unit interposing a delay circuit to the communication A Schmitt circuit electrically connected to the communication interface; and an FET for controlling power supply to the main control unit in accordance with an output of the Schmitt circuit. The chair is RS232C, and the power supply control unit detects a change in the CTS signal by the delay circuit to distinguish between a trigger signal and a noise signal, and when the main control unit runs away, the Schmitt circuit and oN · OFF the FET in accordance with the output state, the lower apparatus characterized that you control the power supply to the main control unit.

  According to the present invention, a communication interface for communicating with a higher-level device, a main control unit that controls the operation of the lower-level device to execute processing according to the situation, and the main control unit runaway Power supply control unit for controlling the power supply to the main control unit, so even if the main control unit runs away, the power control unit supplies power to the main control unit. It is possible to take measures such as shutting down and starting power supply again. Therefore, the subordinate apparatus can be automatically restored, and as a result, convenience can be improved.

  In particular, the present invention is highly convenient in that it does not require an artificial ON / OFF operation such as turning on the power of the host device even when the mode cannot be restored by a normal reset. .

Further, the power supply control unit of the lower-level device according to the present invention includes a Schmitt circuit electrically connected to the communication interface via a delay circuit, and outputs to the main control unit according to the output of the Schmitt circuit. And an FET for controlling power supply .

  According to the present invention, the power supply control unit described above has a Schmitt circuit electrically connected to the communication interface through a delay circuit, and controls power supply to the main control unit according to the output of the Schmitt circuit. Therefore, the lower-level device can be automatically restored while enhancing the noise resistance by the delay circuit or the Schmitt circuit. In particular, even if pulse-like noise is added to the signal sent from the communication interface due to the presence of the delay circuit, its adverse effect (adverse effect of erroneously controlling the power supply to the main controller due to the noise) ) Can be suppressed.

Further, the communication interface of the lower level device according to the present invention is RS232C, and the power supply control unit uses the timing when the RTS signal of the higher level device becomes OFF when the main control unit runs away. The power supply to the main control unit is controlled .

  According to the present invention, the communication interface is RS232C, and the power supply control unit uses the timing when the RTS signal of the host device is turned off when the main control unit runs out of control. Since the supply is controlled, the complexity of the circuit can be prevented. That is, in the present invention, the existing RTS signal defined by RS232C is used as a trigger signal for supplying power to the main control unit, instead of a signal flowing through a new control line. Can be prevented.

(2) in the information processing system having said lower unit and the host device, the host device, when it is detected that the main control unit goes out of control, to a predetermined time OFF the RTS signal of the higher-level device Characteristic information processing system.

  According to the present invention, in the information processing system having the above-described lower apparatus and upper apparatus, the upper apparatus turns off the RTS signal for a predetermined time when it detects that the main control unit has runaway. Thus, the power control unit can control the power supply to the main control unit in response to this, and can automatically return the lower-level device. Further, if the lower-level device can be automatically restored, the system can continue to operate (without being stopped), so that the stability of the entire system can be improved.

  As described above, according to the present invention, even if the main control unit runs out of control, the lower-level device can be automatically restored, and the convenience can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[System configuration]
1 and 2 are block diagrams showing a configuration of an information processing system according to an embodiment of the present invention. FIG. 1 shows an upper apparatus 2 and FIG. 2 shows a magnetic card reader 1 as an example of a lower apparatus. ing.

  The host apparatus 2 includes an application 21 that executes information processing using the lower apparatus 1 connected to the POS terminal via a cable, and a driver module that controls communication between the application 21 and the lower apparatus 1. The driver module includes OPOS 22. The OPOS 22 is defined as an application service interface standard (software) by the OPOS (Open Point of Service) Technical Council. In addition, the host device 2 has various hardware such as a CPU, a ROM, and a RAM (not shown), and has a function of controlling the host device 2 in an integrated manner, a communication function with the lower device 1, and the like.

  The OPOS 22 is composed of two layers of CO (Control Object) and SO (Service Object). The CO is an object provided for each device class of a lower-level device (magnetic card reader, printer, display, etc.), and controls the interface with the application 21. The SO is an object provided for each device of the lower level apparatus, and executes control of each device via the SO.

  The application 21 causes the lower level device 1 to be controlled by the method and property to execute desired control, and receives the result of causing the lower level device 1 to execute control by the event and property.

  The OPOS 22 converts a processing request from the application 21 to the lower level device 1 into a command supported by the lower level device 1 and transmits it, and receives the processing result of the lower level device 1 as a status. Specifically, it is located between application software that executes control of the magnetic card reader 1 constituting the POS terminal system, and standardizes the interface between the host device 2 and the magnetic card reader 1 based on a predetermined specification. Software. The application software receives the result of causing the magnetic card reader 1 to be controlled to execute desired control by a method (Method) or the like, and causing the device to perform control by a return value, event (Event), or parity. ing.

  Although not shown in FIG. 1, the upper device 2 also has a driver module that controls communication between the application 21 and the lower device 1. In addition to OPOS 22, the driver module includes communication control software for actually controlling communication with the lower-level device 1.

  Hereinafter, the magnetic card reader 1 is employed as an example of a lower-level device that communicates with the higher-level device 2 and executes processing according to the situation to transmit the current state and the processing result to the higher-level device 2. The case will be described. The magnetic card reader 1 takes a magnetic card such as a credit card or a prepaid card into a card path, and a magnetic head arranged in the card path contacts and slides on a magnetic stripe formed on the card, Magnetic information is read from or written to the magnetic stripe. Such a magnetic card reader 1 is widely used in ATMs, vending machines, ticket vending machines, POS terminals and the like. In the present embodiment, a case where the magnetic card reader 1 is connected to a POS terminal will be described.

  The POS (Point Of Sales) system is widely used in retail stores and the like. This POS system is a system for collecting single item information when actually selling a product and managing it by a computer in order to grasp which product is sold when and how much. In other words, the POS system is a system that manages data input from a POS terminal (register, personal computer, magnetic card reader, etc.) in real time.

  In FIG. 2, a host device 2 is a POS terminal host, and a magnetic card reader 1 is connected to the POS terminal, and commands (commands) are given to the magnetic card reader 1 and read by the magnetic card reader 1. The received magnetic data is received and a predetermined process is executed. The magnetic card reader 1 connected to the host device 2 has a CPU 11, a CPU power supply 12, a CPU power supply control circuit 13, and an RS receiver 14.

  The CPU 11 controls the entire magnetic card reader in an integrated manner, reads a program from a ROM (not shown), and executes various processes using a RAM (not shown) as a working area. In addition, various processes are executed by receiving power from the CPU power supply 12. The CPU 11 corresponds to an example of a main control unit that controls the operation of the magnetic card reader 1 (integrally or entirely) in order to execute processing according to the situation, but other than the CPU 11 such as an MPU. A thing may be used as the main control unit.

  The RS receiver 14 is electrically connected to the CPU 11, the CPU power supply control circuit 13, and the host device 2. In this embodiment, the RTS signal on the host device 2 side is received as the CTS signal on the magnetic card reader 1 side, and this CTS signal is transmitted to the CPU 11 and the CPU power supply control circuit 13. The RS receiver 14 corresponds to an example of a communication interface that performs communication with the host device 2. Specifically, the host device 2 and the magnetic card reader 1 can communicate with each other according to the RS232C standard, and both the RTS signal and the CTS signal are signals determined by the RS232C. This RS232C is a standard for performing transmission / reception with each signal line, and is one of standard communication (data exchange) methods. Further, the RTS signal line of the host device 2 and the CTS signal line on the magnetic card reader 1 side are cross-connected, and when this cross connection is used, the transmission signal output on the host device 2 side is correctly transmitted. Communication is possible because it is input to the received signal on the side.

  An RTS (Request to send) signal and a CTS (Clear to send) signal are signals transmitted prior to data transmission, and the connection is confirmed before transmission / reception of the data portion. ing.

  Here, the CPU power supply control circuit 13 in the magnetic card reader 1 according to the present embodiment can control the CPU power supply 12 at a desired timing using the RTS signal of the host device 2 as a trigger. Specifically, this will be described in detail with reference to FIG. The CPU power supply control circuit 13 corresponds to an example of a power supply control unit that controls power supply to the CPU 11 when the CPU 11 runs away.

  FIG. 3 is a block diagram showing an electrical configuration of the CPU power supply control circuit 13.

  In FIG. 3, the CPU power supply control circuit 13 connected to the RS receiver 14 includes a delay circuit 131, a Schmitt circuit 132, and an FET 133. The delay circuit 131 includes a resistor R and a capacitor C, and an optimum time constant can be set by adjusting the resistance value and the capacitance, respectively. By setting an optimal time constant, when the CTS signal sent from the RS receiver 14 changes within a predetermined minute time (for example, ON → OFF → ON in 0.5 seconds or less) And the change can be absorbed. Thereby, when using a CTS signal as a trigger signal, a trigger signal and noise can be distinguished. As described above, in this embodiment, the delay circuit 131 is provided so as not to react to a CTS signal of 0.5 seconds or less. In this embodiment, a resistor and a capacitor are used as the delay circuit 131. However, for example, a passive circuit that delays an electric signal for a certain time, such as using an LC filter using a coil and a capacitor, and other equivalent functions are provided. Any circuit may be used as long as it is a circuit.

  As shown in FIG. 3, power is supplied from the host device 2 to the RS receiver 14 and the Schmitt circuit 132.

  The Schmitt circuit 132 is an electronic circuit having hysteresis, and prevents output fluctuation when the CTS signal fluctuates near a threshold value. Specifically, when the potential of the CTS signal exceeds a high threshold, an H level potential is output, and when the potential of the CTS signal falls below a low threshold, an L level potential is output. As a result, even if the amplitude of the CTS signal fluctuates, unintended output fluctuations can be prevented and noise resistance is improved. The specific circuit configuration of the Schmitt circuit 132 may be any type. For example, it may be realized by an operational amplifier with positive feedback, may be realized by adding a Zener diode to the output side of the operational amplifier, may be realized by combining a plurality of transistors, or a logic IC. It may be realized by using.

  The FET (field effect transistor) 133 controls power supply from the power supply 22 of the host device 2 to the CPU power supply 12 using the output (potential change) of the Schmitt circuit 132 as a trigger. Specifically, if the output of the Schmitt circuit 132 is in an ON state (for example, H level), the FET 133 is also turned on, and power is supplied to the CPU power source 12 and at the same time, power is supplied to the CPU 11. On the other hand, if the output of the Schmitt circuit 132 is in an OFF state (for example, L level), the FET 133 is also turned OFF, and the power supply to the CPU power supply 12 is cut off and at the same time the power supply to the CPU 11 is cut off.

  As described above, the CPU power supply control circuit 13 can control the CPU power supply 12 using the RTS signal of the host device 2 as a trigger by using the delay circuit 131, the Schmitt circuit 132, the FET 133, and the like. ing. That is, when the CPU 11 runs out of control, the power supply to the CPU 11 can be controlled using the timing when the RTS signal of the host device 2 is turned off. The RS receiver 14, the Schmitt circuit 132, and the FET 133 are connected to the supply power supply 22 of the host device 2.

[System operation]
Next, the operation of the system shown in FIGS. 1 and 2 will be described. FIG. 4 is an explanatory diagram for explaining the state transition of the OPOS described above, that is, a diagram showing the role (positioning) of the OPOS (software) in the POS terminal system. FIG. 5 is a sequence diagram for explaining return processing when the CPU 11 runs out of control.

  In FIG. 4, the OPOS converts a processing request from the application software to the magnetic card reader 1 into a command supported by the magnetic card reader 1 and transmits it, and the processing result of the magnetic card reader 1 is a status (state). To receive as.

  In the present embodiment, the OPOS in the host device 2 is initially in the Close state (state ST1), and communication between the host device 2 and the magnetic card reader 1 is cut off. Therefore, when the magnetic card reader 1 receives an Open method (a type of command) transmitted from the application software of the host apparatus 2, the Open state (state ST2), that is, the host apparatus 2 uses the magnetic card reader 1 as a result. Transition to the specified state. Further, when the magnetic card reader 1 receives the ClaimDevice method, the state shifts to the Clim state (state ST3), that is, the host device 2 can communicate with the magnetic card reader 1. After that, when the property is set to DeviceEnable = TRUE, the OPOS enters an enable state (state ST4), and the upper device 2 waits to read magnetic information transmitted from the magnetic card reader 2 (waits for input of magnetic information). Standby state). On the other hand, when the OPOS is in the enable state, the magnetic card reader 1 is also in a standby state indicating waiting for input of magnetic information. That is, in this enable state (state ST4), the host device 2 is in a state where it can receive and process magnetic information transmitted from the magnetic card reader 1.

  As shown in FIG. 4, the reverse state transition of the OPOS is the same. When the property setting of DeviceEnable = FALSE is performed from the application software to the OPOS, the state of the OPOS transitions from the state ST4 to the state ST3, and the ReleaseDevice method. Is sent, the state of OPOS transitions from state ST3 to state ST2, and when the Close method is sent, the state of OPOS transitions from state ST2 to state ST1.

  Based on the state transition of the OPOS, the return processing from the CPU runaway will be described in detail. As shown in FIG. 5, first, the property setting of DeviceEnabled = TRUE is performed from the application software to the OPOS (step S1). Receiving this, the OPOS (higher level apparatus 2) transmits an initialization command to the magnetic card reader 1 (lower level apparatus) (step S2). In response to this, an initialization completion response is returned to OPOS. Next, OPOS transmits a device authentication command to the magnetic card reader 1 (step S3). In response to this, a device authentication completion response is returned to OPOS. Next, OPOS transmits an enable command (magnetic information receivable command) to the magnetic card reader 1 (step S4). In response to this, an enable confirmation response is returned to OPOS. Then, the OPOS that has received the enable confirmation response transmits a ResponseCode = OPOS_SUCCESS response to the application software (step S5). As a result, the host device 2 and the magnetic card reader 1 enter a standby state indicating waiting for input of magnetic information. That is, the magnetic card reader 1 is on standby until a magnetic card is inserted. In this embodiment, encryption (DES) is used for magnetic data, and a device authentication command is executed. The device authentication command has a function of confirming whether the magnetic card reader 1 and the OPOS have the same master key and mutually holding keys for key exchange. When the encryption (DES) is not used, the device authentication command is unnecessary.

(Normal operation)
In this standby state, the OPOS periodically sends a swipe completion waiting command to the magnetic card reader 1 at an interval of, for example, 100 ms (step S6). On the other hand, when there is no problem such as the CPU 11 running out of control, a swipe completion wait response is returned to the OPOS.

(If runaway)
Next, if the CPU 11 runs out of control in the magnetic card reader 1, even if OPOS sends a swipe completion waiting command to the magnetic card reader 1 (step S7), no response is returned from the magnetic card reader 1 (step S8). ). Specifically, in response to a swipe completion waiting command transmitted by OPOS, an ACK signal (Acknowledgment signal: when transferring data, a transmission request is transmitted in the sense that the reception side permits transfer in response to a transfer request from the transmission side. When the error that does not return is repeated four times, OPOS determines that the CPU 11 has runaway. In the present embodiment, it is determined that runaway occurs when it is repeated four times based on experience, but the number of times is not limited.

  In such a case, OPOS automatically executes a recovery process from CPU runaway. More specifically, in this embodiment, the OPOS turns off the RTS signal on the host device 2 side for one second with respect to the magnetic card reader 1 (step S9). As a result, as described with reference to FIG. 2, the CTS signal of the RS receiver 14 is turned OFF for one second, the power supply to the CPU power supply 12 is cut off through the delay circuit 131, the Schmitt circuit 132, and the FET 133, and the magnetic card reader 1 is turned off. Thereafter, the RTS signal on the host device 2 side is returned to ON (step S10). As a result, as described with reference to FIG. 2, the CTS signal of the RS receiver 14 is turned ON, and the power supply to the CPU power supply 12 is started again through the delay circuit 131, the Schmitt circuit 132, and the FET 133, and the magnetic card reader 1 Is turned on.

  Thereafter, the magnetic card reader 1 turned on is in the Close state shown in FIG. Therefore, as described above, each method (a type of command) is transmitted from the OPOS from the application software of the host device 2 and is received by the magnetic card reader 1, and the state transitions to the Claim state. Further, a series of commands necessary until DeviceEnabled = TRUE is executed, and the magnetic card reader 1 returns to the card swipe waiting state. That is, in FIG. 5, the OPOS transmits the initialization command, the device authentication command, and the enable command in this order (step S11, step S12, and step S13), thereby causing the magnetic card reader 1 to transition from the initial state to the standby state. . As a result, the system recovers from the error, and the OPOS periodically sends a swipe completion wait command to continue the card swipe wait process (step S14). In steps S2 to S4 and steps S11 to S13, an initialization command, a device authentication command, and an enable command are transmitted to the magnetic card reader 1 in this order. However, the order is limited to this order. is not. For example, the device authentication command and the enable command may be reversed. Further, at least the initialization command and the enable command may be transmitted. If the encryption (DES) is not used, it is not necessary to transmit the device authentication command, and commands other than the device authentication command may be included. .

  FIG. 6 is a flowchart showing the flow of return processing by OPOS.

  As shown in FIG. 6, first, initialization processing is executed in response to the property setting of DeviceEnabled = TRUE (step S31). More specifically, when the property is set from the application to DeviceEnabled = TRUE, the OPOS transmits an initialization command, a device authentication command, and an enable command to the magnetic card reader 1 as described above (FIG. 5). Step S2, Step S3 and Step S4). If the initialization process is successful, that is, if there is no error (step S32: NO), the process proceeds to step S33. On the other hand, if the initialization process fails, that is, if there is an error (step S32: YES), it is determined that an abnormality that cannot be initialized has occurred, and the process ends.

  In step S33, the OPOS is in an enable state (state ST4 shown in FIG. 3), and the card swipe is monitored. On the other hand, the magnetic card reader 1 polls a command for detecting a card swipe (a swipe completion waiting command shown in FIG. 4).

  Here, in a normal operation, a response of confirmation of waiting for completion of swipe is returned to the OPOS when the magnetic card reader 1 is in the card standby state. If a response for confirmation of completion of swipe is not returned, the OPOS (host device 2) determines that some problem has occurred in the magnetic card reader 1.

  Specifically, when no response is returned from the magnetic card reader 1 to the swipe completion waiting command (step S34: YES), it is determined that the CPU 11 has runaway. In the present embodiment, if an error in which an ACK signal is not returned within 500 msec is repeated four times in response to a swipe completion waiting command transmitted by OPOS, OPOS determines that CPU 11 has runaway. If it is determined that the CPU 11 has runaway, as described above, the RTS signal on the host device 2 side is turned off for one second and turned on again (step S35). As a result, the CPU power supply 12 is also turned off for 1 second and turned on again. After the process of step S35, a reset initialization process is performed (step S37). Specifically, as described with reference to FIG. 4, the OPOS transmits an initialization command, a device authentication command, and an enable command to the magnetic card reader 1 in this order (steps S11, S12 and FIG. 4). The magnetic card reader 1 sequentially executes these commands (see step S13). As a result, error recovery is completed. Then, the OPOS proceeds to a card swipe monitoring process (step S33) in which a swipe completion waiting command is periodically transmitted again.

  Next, when an ACK signal is returned from the magnetic card reader 1 in response to the swipe completion waiting command, and then an error code is returned to the OPOS, the CPU 11 has not runaway, causing another problem. It is determined whether or not (step S36). Specifically, this is a case where static electricity reset occurs during card swipe. In this case, the magnetic card reader 1 is initialized, and an uninitialized error response is returned to the OPOS in response to the swipe completion wait command. If no uninitialized error is returned (step S36: NO), the state of the DeviceEnabled property is determined (step S38), and if DeviceEnabled = TRUE, card swipe monitoring is continued (step S33). ). If DeviceEnabled = FALSE (step S38: FALSE), the process ends.

  On the other hand, when an uninitialized error is returned in step S36 (step S36: YES), the above-described return initialization process is performed (step S37).

[Main effects of the embodiment]
As described above, according to the magnetic card reader 1 according to the present embodiment, when the CPU 11 runs out of control, the magnetic card reader 1 is automatically turned on again (step S35 in FIG. 5), and then the initial state is reached. To a standby state (step S37 in FIG. 5). Thereby, the magnetic card reader 1 can be automatically returned, and the convenience can be improved. Further, even when the magnetic card reader 1 itself is reset due to static electricity, it is possible to shift from the initial state to the standby state (step S37 in FIG. 5), so that the magnetic card reader 1 can be automatically returned. , Can increase convenience. As described above, the magnetic card reader 1 according to the present embodiment can appropriately cope with both reset by static electricity and runaway of the CPU 11.

  The OPOS of the host device 2 turns off the RTS signal of the host device 2 for a predetermined time (1 second in this embodiment) when it detects that the CPU 11 has runaway (step S8 in FIG. 4). The card reader 1 can be automatically restored (step S37 in FIG. 5), and the number of error notifications to the application side of the host device 2 can be reduced. If there is no need to perform return processing on the application side of the host device 2, a more robust system can be constructed.

  Further, by using the RTS signal as the trigger signal, it is not necessary to provide a new control line for flowing the trigger signal, and the complexity of the circuit can be prevented. In general, the amount of data in a magnetic card or the like is very small, and it is very unlikely that the host device 2 cannot basically handle the amount of data transmitted from the magnetic card reader 1. Therefore, in the present embodiment, such a situation is utilized effectively to prevent an increase in the number of parts and a complicated circuit.

  In the present embodiment, the RTS signal is used as the trigger signal, but other signals may be used. For example, it is possible to use a control line that is less frequently used, such as a DTR signal (a DSR signal when viewed from the magnetic card reader 1 side) for confirming whether or not the apparatus is turned on. In the present embodiment, the magnetic card reader 1 is considered as a subordinate apparatus, but the present invention is applicable to other devices.

  As described above, the present invention is useful as a device that can automatically perform error recovery of a device and can improve convenience.

It is a block diagram which shows the structure of the system containing the low-order apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the system containing the low-order apparatus which concerns on embodiment of this invention. It is a block diagram which shows the electrical structure of CPU power supply control circuit. It is explanatory drawing for demonstrating the state transition of OPOS. It is a sequence diagram for demonstrating a return process when CPU runaway occurs. It is a flowchart which shows the flow of the return process by OPOS.

1 Magnetic Card Reader 2 Host Device 11 CPU
12 CPU power supply 13 CPU power supply control circuit 14 RS receiver

Claims (2)

In the lower device that communicates with the upper device and executes processing according to the situation, and transmits the current state and processing result to the upper device,
A communication interface for communicating with the host device, receiving an RTS signal of the host device and transmitting a CTS signal;
A main control unit that controls the operation of the lower-level device in order to execute processing according to the situation;
A power control unit that controls power supply to the main control unit based on a CTS signal transmitted from the communication interface when the main control unit runs away ;
The power supply control unit includes a Schmitt circuit electrically connected to the communication interface via a delay circuit, and an FET that controls power supply to the main control unit according to an output of the Schmitt circuit. Prepared,
The communication interface is RS232C,
The power supply control unit detects a change in the CTS signal by the delay circuit to distinguish between a trigger signal and a noise signal, and the FET according to an output state of the Schmitt circuit when the main control unit runs out of control. the by ON · OFF, the lower apparatus characterized that you control the power supply to the main control unit. An information processing system having the lower apparatus and the upper apparatus according to claim 1 ,
When the host device detects that the main control unit has gone out of control, the host device turns off the RTS signal of the host device for a predetermined time.

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