CN213659439U - PCI-CAN bus interface card - Google Patents

Abstract

The utility model provides a PCI changes CAN bus interface card, through setting up the isolation module, on the one hand, the voltage that provides to the PCI interface is kept apart steady voltage and is handled, the power ripple interference signal that exists in the voltage that the filtering PCI interface provided to provide and provide operating voltage for first CAN communication module and second CAN communication module, make the operating voltage of first CAN communication module and second CAN communication module stable, improve the stability of interface card protocol conversion output data; on the other hand, the isolation module supplies power to the first CAN communication module and the second CAN communication module, the working voltage of the processor is provided by the PCI interface, and the first CAN communication module, the second CAN communication module and the processor are not grounded together, so that power isolation is realized, the first CAN communication module, the second CAN communication module and the processor are really isolated from each other without interference, and the stability of interface card protocol conversion output data is improved.

Description

PCI-CAN bus interface card

Technical Field

The utility model relates to a CAN interface card technical field of PCI bus especially relates to PCI changes CAN bus interface card.

Background

The CAN (controller area network bus) bus technology has the characteristics of automatic message filtering retransmission, extremely low bit error rate, high communication rate and the like, and is widely applied to the industrial and military fields. Currently, in order to improve the anti-interference capability of a CAN bus interface card based on PCI (peripheral component interconnect) bus, a photoelectric isolator is usually arranged in a CAN communication module for eliminating the electrical influence existing between a protocol conversion module and a CAN bus data transceiver module in the interface card, and the disadvantage of this method is that: because the protocol conversion module, the CAN bus data transceiver module and the photoelectric isolator in the interface card all use the same power supply to supply power, all modules in the interface card are grounded, and all modules are connected through the same power supply, the photoelectric isolator CAN not completely isolate the electrical influence between the protocol conversion module and the CAN bus data transceiver module, so that the stability of protocol conversion output data of the interface card is low, and the protocol conversion data has errors.

Therefore, in order to solve the above problem, the utility model provides a PCI changes CAN bus interface card through setting up isolation circuit, realizes protocol conversion module and CAN bus data transceiver module's power isolation, improves interface card protocol conversion output data's stability.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a PCI changes CAN bus interface card through setting up isolation circuit, realizes protocol conversion module and CAN bus data transceiver module's power isolation, improves interface card protocol conversion output data's stability.

The technical scheme of the utility model is realized like this: the utility model provides a PCI-CAN bus interface card, which comprises a PCI interface, a processor, a CAN communication module, a CAN signal interface and an isolation module;

the power supply end of the PCI interface outputs voltage to provide working voltage for the processor, the CAN communication module and the isolation module, and the isolation module outputs voltage to provide working voltage for the CAN communication module;

the PCI interface is communicated with the processor through an address/data multiplexing bus, the processor outputs data information to the input end of the CAN communication module through a data bus, and the output end of the CAN communication module is electrically connected with the CAN signal interface.

On the basis of the above technical scheme, preferably, the CAN communication module includes a first CAN communication module and a second CAN communication module;

the working voltage of the first CAN communication module and the second CAN communication module is provided by the PCI interface and the isolation module;

the processor respectively inputs data information to the input end of the first CAN communication module and the input end of the second CAN communication module through the data bus, and the output end of the first CAN communication module and the output end of the second CAN communication module are electrically connected with the CAN signal interface.

Still further preferably, the isolation module includes a first isolation circuit and a second isolation circuit;

the power end of the PCI interface is electrically connected with the input end of the first isolation circuit and the input end of the second isolation circuit respectively, the output end of the first isolation circuit is electrically connected with the power end of the first CAN communication module, and the output end of the second isolation circuit is electrically connected with the power end of the second CAN communication module.

Still further preferably, the first CAN communication module comprises a CAN controller, a photoelectric isolation module CAN bus transceiver circuit;

the power supply end of the PCI interface is respectively and electrically connected with the power supply end of the CAN controller and the first power supply end of the photoelectric isolation module, and the output end of the first isolation circuit is respectively and electrically connected with the second power supply end of the photoelectric isolation module and the power supply end of the CAN bus transceiver circuit;

the processor inputs data information to the input end of the CAN controller through a data bus, and the output end of the CAN controller is electrically connected with the CAN signal interface module through the photoelectric isolation module, the CAN bus receiving and transmitting circuit which are connected in sequence.

Still further preferably, the CAN bus transceiver circuit includes a CAN bus transceiver and a protection circuit;

the output end of the CAN controller is electrically connected with the input end of the CAN bus transceiver through the photoelectric isolation module, and the output end of the CAN bus transceiver is electrically connected with the CAN signal interface through the protection circuit.

Still further preferably, the protection circuit includes a resistor R17, a resistor R18, a capacitor C22, a capacitor C24, a diode D5 and a diode D6;

the output end of the CAN bus transceiver is respectively connected with one end of a resistor R17 and one end of a resistor R18, the other end of the resistor R17 is respectively connected with one end of a capacitor C22, the cathode of a diode D5 and a CAN signal interface, the other end of the capacitor C22 and the anode of a diode D5 are all grounded, the other end of the resistor R18 is respectively connected with one end of the capacitor C24, the cathode of a diode D6 and the CAN signal interface, the other end of the capacitor C24 and the anode of the diode D6 are all grounded.

On the basis of the technical scheme, the device preferably further comprises a terminal resistor setting interface and a terminal resistor;

the termination resistance setting interface includes a CANH interface and a Res-interface.

One end of the terminal resistor is electrically connected with the CAN signal interface, and the other end of the terminal resistor is electrically connected with the Res-interface.

Still further preferably, the system further comprises a memory;

the processor is in data communication with the memory through an ISA data bus.

The utility model discloses a PCI changes CAN bus interface card has following beneficial effect for prior art: (1) the protection circuit is arranged and used for filtering surge voltage and noise interference signals existing in the process of sending or receiving the CAN bus transceiver, so that the phenomenon that peak voltage in the circuit damages a CAN signal interface is prevented, and the stability of protocol conversion output data of the interface card is improved;

(2) the terminal resistor setting interface is used as an access interface of the terminal resistor and comprises a CANH interface and a Res-interface, the wiring state of the terminal resistor setting interface is manually controlled, when the CANH interface and the Res-interface are in short circuit, the terminal resistor is accessed into a PCI-CAN bus interface card and used as a terminal matching resistor, so that the impedance of a slave interface card is matched with the impedance of the interface card, and the stability of data transmission of the interface card is further improved;

(3) by arranging the first CAN communication module and the second CAN communication module, on one hand, the first CAN communication module and the second CAN communication module are respectively used for receiving control signals from a processor and respectively used for configuring two different CAN transmission rates, so that two terminal devices with different transmission rates CAN be accessed by using one PCI-CAN bus interface card, and the applicability of the adapter is improved; on the other hand, the communication data output by the processor are respectively converted, and CAN differential data are output to corresponding CAN bus signal interfaces;

(4) by arranging the isolation module, on one hand, the voltage provided by the PCI interface is isolated and stabilized, power supply ripple interference signals existing in the voltage provided by the PCI interface are filtered, and working voltages are provided for the first CAN communication module and the second CAN communication module, so that the working voltages of the first CAN communication module and the second CAN communication module are stable, and the stability of protocol conversion output data of the interface card is further improved; on the other hand, the isolation module provides isolation voltage for the first CAN communication module and the second CAN communication module, the working voltage of the processor is provided by the PCI interface, and the first CAN communication module, the second CAN communication module and the processor are not in common ground, so that power isolation is realized, the first CAN communication module, the second CAN communication module and the processor are really isolated and do not interfere with each other, and the stability of protocol conversion output data of the interface card is improved;

(5) by arranging the first isolation circuit and the second isolation circuit, the first isolation circuit performs isolation and voltage stabilization processing on the voltage provided by the PCI interface and outputs the isolation voltage to the second power supply end of the photoelectric isolation module and the power supply end of the CAN bus transceiver circuit, and the working voltages of the processor, the CAN controller and the first power supply end of the photoelectric isolation module are provided by the PCI interface, so that the power isolation of the photoelectric isolation module is realized, the power isolation of the CAN bus transceiver circuit from the processor and the CAN controller is realized, the CAN bus transceiver circuit is really isolated from the processor and the CAN controller without interference, and the stability of interface card protocol conversion output data is improved; the second isolation circuit realizes power isolation between the processor and the second CAN communication module, and power supplies of the first CAN communication module and the second CAN communication module are different, so that power isolation between the first CAN communication module and the second CAN communication module is realized, and the stability of interface card protocol conversion output data is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a system structure diagram of the present invention, which is used to convert PCI to CAN bus interface card;

FIG. 2 is a circuit diagram of the PCI interface of the present invention in a PCI to CAN bus interface card;

FIG. 3 is a circuit diagram of a processor and memory in a PCI to CAN bus interface card according to the present invention;

FIG. 4 is a circuit diagram of the CAN controller, the optoelectronic isolation module and the CAN bus transceiver circuit in the PCI to CAN bus interface card of the present invention;

fig. 5 is the utility model discloses a terminal resistance sets up interface, the CAN signal interface and the isolating circuit's that is connected with first CAN communication module circuit diagram among the PCI changes CAN bus interface card.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention. As shown in FIG. 1, the utility model discloses a PCI changes CAN bus interface card, it includes PCI interface, treater, CAN communication module, CAN signal interface, keeps apart module, terminal resistance and sets up interface, terminal resistance and memory.

And the PCI interface is used as an interface for connecting the processor and the host, is used as a data input end for PCI-CAN conversion, and provides working voltage for a PCI-CAN bus interface card. Preferably, as shown in fig. 2, the PCI interface is a standard PCI interface.

And the processor receives PCI protocol data transmitted by the host through the PCI interface, converts the PCI protocol data into CAN protocol data according to a standard protocol converted from PCI-CAN, and transmits the CAN protocol data to the slave. In this embodiment, a power source terminal of the processor is electrically connected to a power source terminal of the PCI interface, the PCI interface communicates with the processor through an address/data multiplexing bus, the processor outputs data information to an input terminal of the CAN communication module through a data bus, and the processor performs data communication with the memory through an ISA data bus. The PCI-CAN conversion algorithm belongs to a standard protocol and also belongs to the prior art, and in the embodiment, the improvement of a software algorithm is not involved, and the embodiment mainly protects the interface type and the hardware structure of a PCI-CAN bus interface card. Preferably, as shown in fig. 3, the processor is a PCI9052 chip; the VDD pin is a power supply terminal.

And the processor reads the equipment information of the slave from the memory and carries out corresponding drive installation. In this embodiment, the processor communicates data with the memory via an ISA data bus. In this embodiment, the internal algorithm and the structure of the memory are not improved, and therefore, the internal algorithm and the structure of the memory are not described in detail herein. Preferably, the memory is a chip ST93SC46 as shown in FIG. 3.

And the CAN communication module is used for receiving the control signal from the processor, configuring the data transmission of the adapter according to the control signal, converting the communication data output by the processor and outputting CAN differential data to the CAN signal interface. In this embodiment, the processor outputs data information to the input end of the CAN communication module through the data bus, and the output end of the CAN communication module is electrically connected with the CAN signal interface. Preferably, in this embodiment, the CAN communication module includes a first CAN communication module and a second CAN communication module.

The first CAN communication module and the second CAN communication module are respectively used for receiving control signals from the processor and respectively used for configuring two different CAN transmission rates, so that two terminal devices with different transmission rates CAN be accessed by using one PCI-CAN bus interface card, and the applicability of the adapter is improved; on the other hand, the communication data output by the processor are respectively converted, and CAN differential data are output to the corresponding CAN bus signal interface. In this embodiment, the processor respectively inputs data information to the input end of the first CAN communication module and the input end of the second CAN communication module through the data bus, and the output end of the first CAN communication module and the output end of the second CAN communication module are both electrically connected to the CAN signal interface. Preferably, in this embodiment, the first CAN communication module and the second CAN communication module have the same structure and operation principle, and therefore, only the structure and operation principle of the first CAN communication module will be described herein. Preferably, as shown in fig. 1, the first CAN communication module includes a CAN controller, a CAN bus transceiver circuit, and a photo-isolation module.

And the CAN controller receives the control signal output by the processor, performs parameter setting on data transmission of the interface card according to the control signal, and converts the communication data signal output by the processor into a CAN signal to be input to the photoelectric isolation module. Wherein, carry out parameter setting and convert CAN protocol data into the CAN signal to the interface card, CAN directly carry out parameter setting and convert CAN protocol data into the CAN signal by the treater, also CAN build the CAN controller through hardware and carry out parameter setting and convert CAN protocol data into the CAN signal, adopt hardware to build the method that the CAN controller carries out parameter setting and converts CAN protocol data into the CAN signal, CAN reduce the work burden of treater, improve the processing speed of treater, therefore, in this embodiment, the CAN controller that adopts hardware to build carries out parameter setting and converts CAN protocol data into the CAN signal. In this embodiment, the processor outputs data information to the input end of the CAN controller through the data bus, and the output end of the CAN controller is electrically connected with the CAN signal interface through the photoelectric isolation module, the CAN bus transceiver circuit and the CAN signal interface which are connected in sequence. In this embodiment, the improvement of the internal algorithm and structure of the CAN controller is not involved, so the internal algorithm and structure of the CAN controller will not be described herein. Preferably, the CAN controller is a SJA1000 chip as shown in fig. 4.

The photoelectric isolation module is used for signal isolation between the CAN controller and the CAN bus transceiver circuit, eliminating the electrical influence between the CAN controller and the CAN bus transceiver circuit, improving the anti-interference capability of the interface card and improving the stability of protocol conversion output data of the interface card. In this embodiment, the output end of the CAN controller is electrically connected to the CAN signal interface through the optoelectronic isolation module and the CAN bus transceiver circuit which are connected in sequence. In this embodiment, the improvement of the structure of the optoelectronic isolation module is not involved, and therefore, the circuit structure of the optoelectronic isolation module is not described again. Preferably, the optoelectronic isolation module is an optical coupler 6N317 as shown in fig. 4; as shown in fig. 4, the optoelectronic isolation module includes two optical couplers 6N317 respectively serving as couplers of transmitting and receiving light of CAN bus data, which are respectively denoted by U7 and U8, pin 8 of U8 is a first power supply terminal of the optoelectronic isolation module, and pin 8 of U7 is a second power supply terminal of the optoelectronic isolation module.

CAN bus transceiver circuit carries out conversion treatment to the CAN signal of photoelectric isolation module output, surge voltage and noise interference signal in the filtering circuit prevent that spike voltage from appearing in the circuit and damaging CAN signal interface, further improve interface card protocol conversion output data's stability to output CAN differential data to CAN signal interface. In this embodiment, the output end of the CAN controller is electrically connected to the CAN signal interface through the optoelectronic isolation module and the CAN bus transceiver circuit which are connected in sequence. Preferably, as shown in fig. 1, the CAN bus transceiver circuit includes a CAN bus transceiver and a protection circuit.

And the CAN bus transceiver is used for converting the CAN signal output by the photoelectric isolation module and outputting CAN differential data to the protection circuit. In this embodiment, the output of the CAN controller is electrically connected to the input of the CAN bus transceiver through the optoelectronic isolation module, and the output of the CAN bus transceiver is electrically connected to the CAN signal interface through the protection circuit. In this embodiment, the improvement of the internal algorithm and the structure of the CAN bus transceiver is not involved, so the internal algorithm and the structure of the CAN bus transceiver are not described herein. Preferably, as shown in fig. 4, the CAN bus transceiver is 82c250 chip.

And the protection circuit is used for filtering surge voltage and noise interference signals existing in the transmitting or receiving process of the CAN bus transceiver, preventing peak voltage in the circuit from damaging a CAN signal interface and further improving the stability of protocol conversion output data of the interface card. In this embodiment, the output terminal of the CAN bus transceiver is electrically connected to the CAN signal interface through the protection circuit. Preferably, as shown in fig. 4, the protection circuit includes a resistor R17, a resistor R18, a capacitor C22, a capacitor C24, a diode D5, and a diode D6; the output end of the CAN bus transceiver is respectively connected with one end of a resistor R17 and one end of a resistor R18, the other end of the resistor R17 is respectively connected with one end of a capacitor C22, the cathode of a diode D5 and a CAN signal interface, the other end of the capacitor C22 and the anode of a diode D5 are all grounded, the other end of the resistor R18 is respectively connected with one end of the capacitor C24, the cathode of a diode D6 and the CAN signal interface, the other end of the capacitor C24 and the anode of the diode D6 are all grounded. The resistor R17, the capacitor C22, the resistor R18 and the capacitor C24 form an RC filter circuit, and the RC filter circuit is used for filtering noise interference signals existing in CAN differential signals output by the CAN bus transceiver; the diode D5 and the diode D6 are transient suppression diodes for preventing surge voltage in the circuit from burning the CAN signal interface.

And the CAN signal interface is used as a CAN interface of a PCI-CAN bus interface card. In this embodiment, two CAN signal interfaces are provided, which are respectively used as signal interfaces of the first CAN communication module and the second CAN communication module, as shown in fig. 5, the CAN signal interface connected to the first CAN communication module in this embodiment is a female connector of DB9, pins 2 and 7 of DB9 are used as data transmission interfaces of CAN differential signals, pin 3 is used as a ground pin, pin 5 is used as a protection pin, and pin 5 is connected to inductor L1 for filtering out electrostatic interference.

The terminal resistor is provided with an interface and a terminal resistor, the terminal resistor is provided with the interface as an access interface of the terminal resistor, as shown in fig. 1, the terminal resistor comprises a CANH interface and a Res-interface, the wiring state of the terminal resistor is manually controlled, when the CANH interface and the Res-interface are in short circuit, the terminal resistor is accessed into a PCI-to-CAN bus interface card and used as a terminal matching resistor, so that the slave and the interface card are matched in impedance, and the stability of data transmission of the interface card is further improved. In this embodiment, one end of the termination resistor is electrically connected to the CAN signal interface, and the other end of the termination resistor is electrically connected to the Res-interface. Preferably, as shown in fig. 4, the resistor R20 is a termination resistor; as shown in fig. 5, the terminal resistor setting interface selects a 2pin connection terminal, and pin 1 is used as Res-interface and pin 2 is used as CANH interface.

On one hand, the isolation module carries out isolation and voltage stabilization treatment on the voltage provided by the PCI interface, filters power supply ripple interference signals in the voltage provided by the PCI interface, and provides working voltage for the first CAN communication module and the second CAN communication module, so that the working voltage of the first CAN communication module and the second CAN communication module is stable, and the stability of protocol conversion output data of the interface card is further improved; on the other hand, because the protocol conversion module, the CAN bus data transceiver module and the photoelectric isolator in the existing PCI-to-CAN bus interface card all use the same power supply for power supply, and all modules in the interface card are grounded and connected through the same power supply, the photoelectric isolator cannot completely isolate the electrical influence between the protocol conversion module and the CAN bus data transceiver module, so that the stability of protocol conversion output data of the interface card is low, and the protocol conversion data has errors; therefore, in order to solve the above problems, in this embodiment, the isolation module is configured to provide isolation voltage for the first CAN communication module and the second CAN communication module, the working voltage of the processor is provided by the PCI interface, and the first CAN communication module, the second CAN communication module and the processor are not grounded together, so that power isolation is realized, the first CAN communication module, the second CAN communication module and the processor are really isolated and do not interfere with each other, and the stability of the interface card protocol conversion output data is improved. In this embodiment, the power supply terminal of the PCI interface outputs a voltage to provide a working voltage for the processor, the first CAN communication module, the second CAN communication module, and the isolation module outputs a voltage to provide a working voltage for the first CAN communication module and the second CAN communication module. Preferably, the isolation module includes a first isolation circuit and a second isolation circuit.

The first isolation circuit isolates and stabilizes voltage of the voltage provided by the PCI interface, and outputs the isolated voltage to a second power end of the photoelectric isolation module and a power end of the CAN bus transceiver circuit, and the processor, the CAN controller and the working voltage of the first power end of the photoelectric isolation module are provided by the PCI interface, so that the power isolation of the photoelectric isolation module is realized, the CAN bus transceiver circuit is isolated from the processor and the power of the CAN controller, so that the CAN bus transceiver circuit is truly isolated from the processor and the CAN controller, mutual interference is avoided, and the stability of protocol conversion output data of an interface card is improved. The second isolation circuit realizes power isolation between the processor and the second CAN communication module, and power supplies of the first CAN communication module and the second CAN communication module are different, so that power isolation between the first CAN communication module and the second CAN communication module is realized, and the stability of interface card protocol conversion output data is further improved. In this embodiment, the power source end of the PCI interface is electrically connected to the power source end of the CAN controller, the first power source end of the optoelectronic isolation module, the input end of the first isolation circuit, and the input end of the second isolation circuit, the output end of the second isolation circuit is electrically connected to the power source end of the second communication module, and the output end of the first isolation circuit is electrically connected to the second power source end of the optoelectronic isolation module and the power source end of the CAN bus transceiver circuit. The present embodiment does not involve the improvement of the structures of the first isolation circuit and the second isolation circuit, and therefore, the structures of the two isolation circuits will not be described again here. Preferably, as shown in fig. 5, the first isolation circuit is DC0505-1W, and +5V0 is the voltage output by the first isolation circuit.

Because first CAN communication module and second CAN communication module's structure and theory of operation are all the same, only introduce here when carrying out data transmission through first communication module and terminal equipment the utility model discloses a concrete theory of operation: the PCI interface outputs voltage to a power supply end of the processor, a power supply end of the CAN controller, a first power supply end of the photoelectric isolation module and a first isolation circuit, and the first isolation circuit carries out isolation and voltage stabilization processing on the voltage provided by the PCI interface; on the other hand, the isolation voltage is output to a second power supply end of the photoelectric isolation module and a power supply end of the CAN bus transceiver circuit, and working voltages of the processor, the CAN controller and a first power supply end of the photoelectric isolation module are provided by the PCI interface, so that power isolation of the photoelectric isolation module is realized, and power isolation of the CAN bus transceiver circuit from the processor and the CAN controller is realized; after the interface card is electrified, the host transmits PCI protocol data to the processor through the PCI interface, the processor converts the PCI protocol data into CAN protocol data according to a standard protocol converted from PCI-CAN and transmits the CAN protocol data to the CAN controller, the CAN controller carries out parameter setting and carries out signal isolation on the CAN protocol data through the photoelectric isolation module and then inputs the CAN protocol data to the CAN bus transceiving circuit, the CAN bus transceiving circuit converts the CAN protocol data into CAN differential data and inputs the CAN differential data to the protection circuit for filtering processing, and the protection circuit transmits the filtered CAN differential data to the slave through the CAN signal interface.

The utility model has the advantages that: the protection circuit is arranged and used for filtering surge voltage and noise interference signals existing in the process of sending or receiving the CAN bus transceiver, so that the phenomenon that peak voltage in the circuit damages a CAN signal interface is prevented, and the stability of protocol conversion output data of the interface card is improved;

the terminal resistor setting interface is used as an access interface of the terminal resistor and comprises a CANH interface and a Res-interface, the wiring state of the terminal resistor setting interface is manually controlled, when the CANH interface and the Res-interface are in short circuit, the terminal resistor is accessed into a PCI-CAN bus interface card and used as a terminal matching resistor, so that the impedance of a slave interface card is matched with the impedance of the interface card, and the stability of data transmission of the interface card is further improved;

by arranging the first CAN communication module and the second CAN communication module, on one hand, the first CAN communication module and the second CAN communication module are respectively used for receiving control signals from a processor and respectively used for configuring two different CAN transmission rates, so that two terminal devices with different transmission rates CAN be accessed by using one PCI-CAN bus interface card, and the applicability of the adapter is improved; on the other hand, the communication data output by the processor are respectively converted, and CAN differential data are output to corresponding CAN bus signal interfaces;

by arranging the isolation module, on one hand, the voltage provided by the PCI interface is isolated and stabilized, power supply ripple interference signals existing in the voltage provided by the PCI interface are filtered, and working voltages are provided for the first CAN communication module and the second CAN communication module, so that the working voltages of the first CAN communication module and the second CAN communication module are stable, and the stability of protocol conversion output data of the interface card is further improved; on the other hand, the isolation module provides isolation voltage for the first CAN communication module and the second CAN communication module, the working voltage of the processor is provided by the PCI interface, and the first CAN communication module, the second CAN communication module and the processor are not in common ground, so that power isolation is realized, the first CAN communication module, the second CAN communication module and the processor are really isolated and do not interfere with each other, and the stability of protocol conversion output data of the interface card is improved;

by arranging the first isolation circuit and the second isolation circuit, the first isolation circuit performs isolation and voltage stabilization processing on the voltage provided by the PCI interface and outputs the isolation voltage to the second power supply end of the photoelectric isolation module and the power supply end of the CAN bus transceiver circuit, and the working voltages of the processor, the CAN controller and the first power supply end of the photoelectric isolation module are provided by the PCI interface, so that the power isolation of the photoelectric isolation module is realized, the power isolation of the CAN bus transceiver circuit from the processor and the CAN controller is realized, the CAN bus transceiver circuit is really isolated from the processor and the CAN controller without interference, and the stability of interface card protocol conversion output data is improved; the second isolation circuit realizes power isolation between the processor and the second CAN communication module, and power supplies of the first CAN communication module and the second CAN communication module are different, so that power isolation between the first CAN communication module and the second CAN communication module is realized, and the stability of interface card protocol conversion output data is further improved.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. PCI changes CAN bus interface card, and it includes PCI interface, treater, CAN communication module and CAN signal interface, its characterized in that: the system also comprises an isolation module;

   the power supply end of the PCI interface outputs voltage to provide working voltage for the processor, the CAN communication module and the isolation module, and the isolation module outputs voltage to provide working voltage for the CAN communication module;

   the PCI interface is communicated with the processor through an address/data multiplexing bus, the processor outputs data information to the input end of the CAN communication module through a data bus, and the output end of the CAN communication module is electrically connected with the CAN signal interface.
2. 2. The PCI-to-CAN bus interface card of claim 1, wherein: the CAN communication module comprises a first CAN communication module and a second CAN communication module;

   the working voltages of the first CAN communication module and the second CAN communication module are provided by a PCI interface and an isolation module;

   the processor inputs data information to the input end of the first CAN communication module and the input end of the second CAN communication module respectively through the data bus, and the output end of the first CAN communication module and the output end of the second CAN communication module are electrically connected with the CAN signal interface.
3. 3. The PCI-to-CAN bus interface card of claim 2, wherein: the isolation module comprises a first isolation circuit and a second isolation circuit;

   the power supply end of the PCI interface is electrically connected with the input end of the first isolation circuit and the input end of the second isolation circuit respectively, the output end of the first isolation circuit is electrically connected with the power supply end of the first CAN communication module, and the output end of the second isolation circuit is electrically connected with the power supply end of the second CAN communication module.
4. 4. The PCI-to-CAN bus interface card of claim 3, wherein: the first CAN communication module comprises a CAN controller and a photoelectric isolation module CAN bus transceiver circuit;

   the power supply end of the PCI interface is electrically connected with the power supply end of the CAN controller and the first power supply end of the photoelectric isolation module respectively, and the output end of the first isolation circuit is electrically connected with the second power supply end of the photoelectric isolation module and the power supply end of the CAN bus transceiver circuit respectively;

   the processor inputs data information to the input end of the CAN controller through a data bus, and the output end of the CAN controller is electrically connected with the CAN signal interface module through a photoelectric isolation module, a CAN bus receiving and transmitting circuit which are connected in sequence.
5. 5. The PCI-to-CAN bus interface card of claim 4, wherein: the CAN bus transceiver circuit comprises a CAN bus transceiver and a protection circuit;

   the output end of the CAN controller is electrically connected with the input end of the CAN bus transceiver through the photoelectric isolation module, and the output end of the CAN bus transceiver is electrically connected with the CAN signal interface through the protection circuit.
6. 6. The PCI-to-CAN bus interface card of claim 5, wherein: the protection circuit comprises a resistor R17, a resistor R18, a capacitor C22, a capacitor C24, a diode D5 and a diode D6;

   the output end of the CAN bus transceiver is respectively electrically connected with one end of a resistor R17 and one end of a resistor R18, the other end of the resistor R17 is respectively electrically connected with one end of a capacitor C22, the cathode of a diode D5 and a CAN signal interface, the other end of the capacitor C22 and the anode of a diode D5 are all grounded, the other end of the resistor R18 is respectively electrically connected with one end of the capacitor C24, the cathode of a diode D6 and the CAN signal interface, and the other end of the capacitor C24 and the anode of the diode D6 are all grounded.
7. 7. The PCI-to-CAN bus interface card of any of claims 1-6, wherein: the device also comprises a terminal resistor setting interface and a terminal resistor;

   the terminal resistor setting interface comprises a CANH interface and a Res-interface;

   one end of the terminal resistor is electrically connected with the CAN signal interface, and the other end of the terminal resistor is electrically connected with the Res-interface.
8. 8. The PCI-to-CAN bus interface card of claim 7, wherein: also includes a memory;

   the processor is in data communication with the memory through an ISA data bus.

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