CN214011973U - Serial port expansion device and computer equipment - Google Patents
Serial port expansion device and computer equipment Download PDFInfo
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- CN214011973U CN214011973U CN202120135982.0U CN202120135982U CN214011973U CN 214011973 U CN214011973 U CN 214011973U CN 202120135982 U CN202120135982 U CN 202120135982U CN 214011973 U CN214011973 U CN 214011973U
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Abstract
The application relates to communication equipment, provides a serial ports extension fixture and computer equipment, and the serial ports extension fixture includes at least one input serial ports, programmable logic device and a plurality of serial interface, programmable logic device is in at least one input serial ports with all be equipped with interface channel between a plurality of serial interface, just programmable logic device with between the input serial ports and programmable logic device with at least one side is equipped with protection circuit between the serial interface. The programmable logic device is introduced to expand the serial ports, switching of different serial ports can be realized through a switching channel, and information interaction is further realized, and compared with the prior art, low-cost serial interface expansion without limitation is realized; in addition, a protection circuit is arranged on the input and output serial port, so that the serial port can bear corresponding surge, and the reliability of the equipment is improved.
Description
Technical Field
The application belongs to the technical field of communication, and particularly relates to a serial port expansion device and computer equipment.
Background
At present, a scenario of one serial port connected with multiple serial ports is mainly realized by two schemes, namely scheme 1: expanding the USB into 4 serial ports by adopting a four-port serial port expansion method; scheme 2: the serial port is extended by adopting a serial port server mode and using a scheme of Transmission Control Protocol/Internet Protocol (TCP/IP).
For the scheme 1, the use of a special chip is limited, the number of the serial ports is very inconvenient to expand, only serial port expansion chips supporting 2 types, 4 types and 8 types of expansion are available in the market at present, and more than 8 serial ports are difficult to realize; in addition, the user serial port connection cannot intelligently select the standard DB9 serial port or the USB serial port, and only the USB communication port can be used.
For the scheme 2, the hardware circuit design is extremely complex, the software system is huge, the TCP/IP protocol stack processing is involved, the function is complex, and the cost of hardware materials and the cost of software development are extremely high.
Disclosure of Invention
The application aims to provide a serial port expansion device and aims to solve the problems that the expansion quantity is limited or the cost is high in the traditional serial port expansion.
A first aspect of the embodiments of the present application provides a serial port expansion device, including at least one input serial port, programmable logic device and a plurality of serial interfaces, programmable logic device is in at least one input serial port with all be equipped with interface channel between a plurality of serial interfaces, just programmable logic device with between the input serial port and programmable logic device with at least one side is equipped with protection circuit between the serial interfaces.
In one embodiment, the programmable logic device is a CPLD.
In one embodiment, a protection circuit is arranged between the programmable logic device and the input serial port.
In one embodiment, a protection circuit is arranged between the programmable logic device and the serial interface.
In one embodiment, the protection circuit includes:
one end of the first TVS tube is connected with the input serial port or the TX line of the serial interface, and the other end of the first TVS tube is grounded;
one end of the second TVS tube is connected with the input serial port or the RX line of the serial interface, and the other end of the second TVS tube is grounded;
one end of the first inductor is connected with a TX line of the input serial port;
one end of the second inductor is connected with an RX line of the input serial port;
one end of the first piezoresistor is connected with the other end of the first inductor, and the other end of the first piezoresistor is grounded;
one end of the second piezoresistor is connected with the other end of the second inductor, and the other end of the second piezoresistor is grounded;
and a common mode choke coil, wherein two terminals on a first side are connected with the TX line and the RX line, and two terminals on a second side are coupled to the programmable logic device.
In one embodiment, the response time of the first inductor and the first piezoresistor and the response time of the second inductor and the second piezoresistor are ns.
In one embodiment, a level conversion circuit is arranged between the input serial port and the programmable logic device.
In one embodiment, a level conversion circuit is arranged between the programmable logic device and the serial interface. In one embodiment, the level conversion circuit is a level conversion chip suitable for RS232/RS422/RS 485.
In one embodiment, the at least one input serial port comprises at least one of a USB port, a standard serial port of DB9 type, and an RJ45 serial port.
In one embodiment, the serial interface is a UART interface.
A second aspect of the embodiments of the present application provides a computer device, including the above serial port expansion apparatus.
The serial port expansion device expands the serial port by introducing the programmable logic device, can realize the switching of different serial ports through a switching channel, further realize information interaction, and compared with the prior art, realizes the expansion of serial ports with low cost and without limitation; in addition, still set up protection circuit on input/output's serial ports, can guarantee that the serial ports can bear corresponding surge, improve equipment's reliability, to the frame switch frame of using this scheme, the benefit lies in can also supporting integrated circuit board hot plug.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of a serial port expansion device provided in an embodiment of the present application;
FIG. 2 is a block diagram of the serial port expansion apparatus shown in FIG. 1;
fig. 3 is a circuit diagram of a protection circuit in the serial port expansion device shown in fig. 2.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Referring to fig. 1, an embodiment of the present application provides a serial port expansion apparatus, which includes at least one input serial port 11, a programmable logic device 12, and a plurality of serial ports 13, where the programmable logic device 12 is provided with a connection channel between the at least one input serial port 11 and the plurality of serial ports 13, and at least one side of the programmable logic device 12 and the input serial port 11 and between the programmable logic device 12 and the serial ports 13 is provided with a protection circuit.
The programmable logic device 12 is configured to, when receiving the connection request, determine a target connection channel according to the connection request, and open the target connection channel to establish a connection between the input serial port 11 and the target serial interface 13. The transparent transmission of one-to-many serial port signals of the input serial port 11 is realized, the Modbus and other protocols set by a user can be compatible, and the method can also be applied to other distributed multi-serial port networks.
In one embodiment, the programmable logic device 12 is a Complex Programmable Logic Device (CPLD) 12. The CPLD is used for supporting higher transmission rate and can be compatible with various baud rates of 100 bps-115200 bps and the like.
In one embodiment, the at least one input serial port 11 comprises at least one of a USB port, a standard serial port of DB9 type, and an RJ45 serial port. When the USB interface is applied to a frame type switch system, a user can conveniently use a single USB interface or a standard serial interface to switch to a plurality of different board card serial interfaces under the scene. In one embodiment, the serial interface 13 is a UART interface.
When the method is applied to a frame type switch system, the CPLD detects whether a switch panel port is inserted into a USB port or a DB9 type standard serial port or an RJ45 serial port, then selects a corresponding high-priority port as serial port input according to the preset priority of an input serial port 11, and then effectively switches to a serial port 13 corresponding to a switch board card according to a user connection request. For example, the CPLD preferentially detects whether the USB port is inserted, and selects the USB port as a serial port of the control panel when the USB is inserted; when a standard serial port of DB9 type is inserted, the corresponding port is selected. If the input serial ports 11 of the two ports are both plugged, the external port is connected according to the preset priority, in this example, the preset USB port is preferred, and when the input serial ports are not plugged, the system can perform port detection polling again every 5 s.
Therefore, the integrated circuit board can be effectively connected to serial ports of a plurality of different board cards through an external single serial port, debugging and analysis of each board card are greatly facilitated, and software and hardware function configuration is achieved.
Referring to fig. 2, in one embodiment, a protection circuit 14 is disposed between the programmable logic device 12 and the input serial port 11. In one embodiment, a protection circuit 14 is disposed between the programmable logic device 12 and the serial interface 13. The serial port expansion device has a lightning protection function and extremely strong anti-interference capability, and can be applied to severe electromagnetic environments such as the field of industrial control.
Furthermore, a level conversion circuit is connected between the input serial port 11 and the programmable logic device 12. Optionally, a level shift circuit is also provided between the programmable logic device 12 and the serial interface 13. The level shifter circuit is used to shift between high and low levels or to pull up/down the level voltage so that the level signal is recognized by the programmable logic device 12 and the motherboard. The level conversion circuit 15 can make the serial device compatible with RS232/RS422/RS485 level.
Referring to fig. 3, in one embodiment, the protection circuit 14 includes: a first Transient Voltage Super (TVS) D1, a second TVS tube D2, a first inductor L1, a second inductor L2, a first varistor R1, a second varistor R2, and a common mode choke L3.
A first Transient Voltage Super (TVS) 11, wherein one end of the first TVS tube 11 is connected to the input serial port 11 or a TX line of the serial port 13, and the other end of the first TVS tube 11 is grounded;
one end of the second TVS tube D2 is connected to an RX line of the input serial port 11 or the serial port 13, and the other end of the second TVS tube D2 is grounded; one end of the first inductor L1 is connected to the TX line of the input serial port 11; one end of the second inductor L2 is connected to an RX line of the input serial port 11; one end of the first piezoresistor R1 is connected with the other end of the first inductor L1, and the other end of the first piezoresistor R1 is grounded; one end of the second piezoresistor R2 is connected with the other end of the second inductor L2, and the other end of the second piezoresistor R2 is grounded; the TX line and the RX line are connected to the two terminals 2 and 3 on the first side of the common mode choke coil L3, and the programmable logic device 12 is connected to the two terminals 1 and 4 on the second side of the common mode choke coil L3 via the level shifter circuit 15.
Common-mode surge protection is carried out by combining a piezoresistor and an inductor; the TVS tube carries out differential mode signal protection; the common mode choke coil L3 is used for filtering and eliminating high-frequency noise; the serial port has good electromagnetic anti-interference and lightning stroke protection effects due to the use of the protection circuit, the serial port can be compatible with severe electromagnetic environments such as electric power and industrial plants, and the protection circuit 14 can protect equipment from normal level operation during hot plugging.
The common mode protection uses a voltage dependent resistor and an inductor, the response time of the common mode protection is ns level, if the response time is 100ns, if the voltage dependent voltage is 100V, the voltage dependent resistor is considered to be conducted after the voltage reaches 100V and then passes 100 ns. For a surge lightning stroke waveform with 6kV peak voltage, the voltage change rate is 600kV/us, namely V is 100 to 600 t, so t is 0.16ns, and the actual response time of the piezoresistor is about 100ns +0.016ns and about 0.1 us. 0.1us before the response time, the lightning protection TVS requires that before the voltage dependent resistor is conducted and the TVS tube is protected, the current of the TVS tube is not greater than the maximum current of the TVS tube, and then the TVS tube can be protected. Therefore, MOV protection and TVS protection are combined, and the serial port can be guaranteed to bear corresponding surge.
In one embodiment, the level conversion circuit 15 is a level conversion chip suitable for RS232/RS422/RS485, has good level compatibility, and can support standard protocols such as RS232/RS422/RS 485.
A second aspect of the embodiments of the present application provides a computer device including the above serial port expansion apparatus, for example, a frame switch, as a serial port expansion apparatus, which is very convenient for a user to query states of each board card by using a single serial port, and configure operations such as parameters of each board card. The system can support and expand 2-n serial ports (n > -18), and is conveniently used for a machine frame switch of multi-board cards such as 3, 6, 12, 18 and the like.
The serial port expansion device introduces the programmable logic device 12 to expand the serial port, and can realize the switching of different serial ports through a switching channel so as to realize information interaction, and compared with the prior art, the serial port expansion device realizes the expansion of serial ports 13 with low cost and without limitation; in addition, a protection circuit 14 is arranged on the input and output serial port, so that the serial port can bear corresponding surge, and the reliability of the equipment is improved; for the frame type switch machine frame applying the scheme, the method has the advantage that the hot plugging of the board card can be supported.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (12)
1. A serial port expansion device is characterized by comprising at least one input serial port, a programmable logic device and a plurality of serial ports, wherein connecting channels are arranged between the at least one input serial port and the plurality of serial ports of the programmable logic device, and at least one side between the programmable logic device and the input serial port and between the programmable logic device and the serial ports is provided with a protection circuit.
2. The serial port expansion device according to claim 1, wherein the programmable logic device is a CPLD.
3. The serial port expansion device according to claim 1, wherein a protection circuit is arranged between the programmable logic device and the input serial port.
4. The serial port expansion device according to claim 1 or 3, wherein a protection circuit is provided between the programmable logic device and the serial interface.
5. The serial port expansion device according to claim 4, wherein the protection circuit comprises:
one end of the first TVS tube is connected with the input serial port or the TX line of the serial interface, and the other end of the first TVS tube is grounded;
one end of the second TVS tube is connected with the input serial port or the RX line of the serial interface, and the other end of the second TVS tube is grounded;
one end of the first inductor is connected with a TX line of the input serial port;
one end of the second inductor is connected with an RX line of the input serial port;
one end of the first piezoresistor is connected with the other end of the first inductor, and the other end of the first piezoresistor is grounded;
one end of the second piezoresistor is connected with the other end of the second inductor, and the other end of the second piezoresistor is grounded;
and a common mode choke coil, wherein two terminals on a first side are connected with the TX line and the RX line, and two terminals on a second side are coupled to the programmable logic device.
6. The serial port expansion device according to claim 5, wherein the response time of the first inductor and the first voltage dependent resistor, and the response time of the second inductor and the second voltage dependent resistor are ns-level.
7. The serial port expansion device according to claim 1, wherein a level shift circuit is provided between the input serial port and the programmable logic device.
8. The serial port expansion device according to claim 7, wherein a level conversion circuit is provided between the programmable logic device and the serial interface.
9. The serial port expansion device according to claim 7 or 8, wherein the level conversion circuit is a level conversion chip suitable for RS232/RS422/RS 485.
10. The serial port extension device of claim 1 wherein the at least one input serial port comprises at least one of a USB port, a DB9 type standard serial port, and an RJ45 serial port.
11. The serial port extension device of claim 1, wherein the serial interface is a UART interface.
12. A computer device comprising the serial port expansion apparatus of any one of claims 1 to 9.
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| CN202120135982.0U CN214011973U (en) | 2021-01-18 | 2021-01-18 | Serial port expansion device and computer equipment |
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| CN202120135982.0U CN214011973U (en) | 2021-01-18 | 2021-01-18 | Serial port expansion device and computer equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114461567A (en) * | 2022-03-01 | 2022-05-10 | 浙江禾川科技股份有限公司 | Data processing equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114461567A (en) * | 2022-03-01 | 2022-05-10 | 浙江禾川科技股份有限公司 | Data processing equipment |
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