KR100715866B1 - Apparatus of Communication with Each Device consisting of Analog?Digital Converter - Google Patents

Abstract

The present invention relates to a ground processing method for communication between heterogeneous equipment including an analog-to-digital conversion circuit, and characterized in that the heterogeneous equipment is provided with a dedicated ground for communication between the heterogeneous equipment. As described above, by designing a communication-only ground inside each device of this type of equipment and processing it separately, it is possible to prevent data loss and abnormality caused by potential difference that may occur in the existing communication ground in advance.

Analog, Digital, Converter, Ground, Bead, Serial Communication, RS232C, RS422 / 485

Description

Apparatus of Communication with Each Device consisting of Analog-Digital Converter}

1A and 1B are pin configuration diagrams of an RS232C connector.

2 is a block diagram illustrating a ground processing method when a serial communication connection (RS232C or RS422 / 485) is used for data communication between heterogeneous devices.

3 is a block diagram illustrating a ground processing method when a serial communication connection (RS232C or RS422 / 485) is used for data communication between heterogeneous devices according to an embodiment of the present invention.

{Description of Major Symbols in Drawings}

200a, 300a: device 1 200b, 300b: device 2

201a, 201b: Microcontroller 202a, 202b: Buffer

203a, 203b: MAX232C IC 204a, 204b: Bead

205a, 205b: analog ground 206a, 206b: digital ground

207a, 207b: Connector 301a, 301b: Communication only ground

The present invention relates to a ground processing method for communication between heterogeneous devices including an analog-to-digital conversion circuit. In particular, the present invention relates to communication that may be caused when equipment including an analog-to-digital conversion circuit transmits data through a physical connection. It relates to a ground processing method for preventing errors.

Currently, wired or wireless communication methods are used to transfer data between these devices. The wired communication method includes a serial communication method such as RS232C or RS422 / 485 and a parallel communication method, and the infrared communication method (Infrared Data Association, 'IrDA') is typical.

Among the above methods, wired communication methods are commonly used. However, in the wired communication method, parallel communication is difficult to implement and expensive, and distance is also limited. On the other hand, serial communication is easy to implement, inexpensive, and is commonly used because distance limitations are less constrained than parallel. Hereinafter, the RS232C which is a serial communication method commonly used between the models will be described.

RS232C is an abbreviation of 'Recommended Standard-232C' and is an interface standard for interconnecting a computer and a peripheral device or a data terminal device (DTE) and a data line termination device (DCE). Many personal computers (PCs) employ RS-232 as their input / output serial interface. RS-232C is the physical interface that interconnects the DTE and DCE. In case of connecting modem with PC, PC is DTE and modem is DCE. Communication speeds are up to 20kbps, full duplex / half duplex, synchronous / asynchronous. The interconnection circuit, electrical and mechanical characteristics of the RS-232C are compatible with ITU-T Recommendations V.24 (interconnect circuit), V.28 (electrical characteristic) and ISO 2110 (DB-25 connector), respectively. The RS-232C cable connector uses a traditional 25-pin DB connector. The maximum cable length is 12.25m, but it can be extended by increasing the signal's voltage. Recently, a 9-pin DB-9 connector has been used. RS-232C was revised to ANSI / EIA 232D in 1987, but is not very aware of the computer industry.

1 is a configuration diagram of a connector of RS232C, in which FIG. 1A shows an RS232C 25-pin connector and FIG. 1B shows an RS232C 9-pin connector.

 Referring to the signal line provided in the connector of FIGS. 1A and 1B, TXD is an abbreviation of Transmit Data, and is a signal line from which serial communication data comes out when an asynchronous serial communication device sends information to an external device.

RXD stands for Receive Data, and is a signal line that receives serial communication data from an external device.

RTS stands for Ready To Send, a signal line that indicates that a DTE device, such as a computer, is ready to receive data from a DCE device, such as a modem or printer.

CTS stands for Clear To Send, a signal line that indicates that a DCE device, such as a modem or printer, is ready to receive data from a DTE device, such as a computer.

 DTR is an abbreviation of Data Terminal Ready. It is a signal line that informs the modem that the computer or terminal is in a state where it can transmit and receive. In general, DTR outputs this signal after the computer initializes the communication port after power is applied.

 DSR stands for Data Set Ready. It is a signal line that tells the computer or terminal that it can send and receive. Generally, DSR outputs this signal when the modem checks its status after powering on the modem.

 DCD stands for Data Carrier Detect and is a signal line that informs the computer or terminal that the modem of the other side sends a carrier signal when the modem is connected through the other side of the modem and telephone line.

 RI is an abbreviation for Ring Indicator, and when the other modem dials in first, it will ring. At this time, the modem recognizes this signal and informs the computer or terminal. In general, when the computer receives this signal, it calls a program that responds to the ringing signal through an interrupter.

FIG. 2 is connected to a device having an analog-to-digital conversion circuit by using a communication device such as RS232C or RS422 / 485 when a physical communication connection between these devices is required for data communication with another device. The communication device adjusts the data transmission / reception level using the MAX232c ICs 203a and 203b, and temporarily stores the data in the buffers 202a and 202b to process the data in the microcontrollers 201a and 201b. At this time, the communication lines (Tx, Rx) of the communication equipment is connected in a cross, the ground line is connected to the digital ground 206a in the device 1 (200a), and the analog ground (in device 2 (200b)) according to the characteristics of the circuit design 205b).

As described above, when designing a circuit in which both an analog circuit and a digital circuit exist at the same time, the ground processing method of the analog circuit and the digital circuit is separately grounded or the circuit is designed in connection with the beads. In order to physically connect the devices including the analog-to-digital conversion circuit, communication equipment (RS232C, RS422 / 485) is used, but it is not a problem when connecting to the infrared port, but it is a ground pin such as RS232C or RS422 / 485. Telecommunication equipment that needs to be handled can cause problems.

That is, the communication lines (Tx, Rx) of the communication device are connected by cross between these models, but the digital ground of the A device is connected with the analog ground of the B device or the A device when the communication ground processing of the equipment with analog-to-digital conversion circuit is performed. It is possible that the analog ground signal at is linked to the digital ground signal at device B. If the ground characteristics of these devices are different, there is a possibility that a ground potential difference may occur in communication, and noise and data loss may occur during data transmission and reception.

The present invention has been made to solve the above problems, and prevents noise and data loss that may occur during data transmission and reception due to the ground potential difference according to the ground characteristic difference between the equipment including the analog-to-digital conversion circuit. It is to provide a ground treatment method.

In order to achieve the above object, the ground processing method for communication between heterogeneous equipments including the analog-to-digital conversion circuit of the present invention is characterized in that the heterogeneous equipment is provided with a dedicated ground separately for communication between heterogeneous equipments. .

In the present invention, it is preferable that the communication method uses a serial communication method.

In the present invention, the serial communication method preferably uses RS232C or RS422 / 485.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

3 is a block diagram illustrating a ground processing method for communication between heterogeneous devices including an analog-to-digital conversion circuit according to an embodiment of the present invention.

In the above embodiment, this model includes the microcontrollers 201a and 201b, the buffers 202a and 202b, the MAX232C ICs 203a and 203b, the analog grounds 205a and 205b, the digital grounds 206a and 206b, and the beads 204a. 204b) and communication dedicated grounds 301a and 301b.

The above embodiment schematically illustrates a ground processing method when a serial communication connection (RS232C or RS422 / 485) is used for data communication between the devices.

Referring to Figure 3, using the serial communication method RS232C or RS422 / 485 for this type of data communication, the connector 207a, 207b used for the serial communication is currently known RS232C or RS422 / 485 The number of connectors and pins used in the cable for communication and the signals processed by each pin are the same.

Each device 1, 2 is provided with a communication dedicated ground (301a, 301b) separately. The communication-only grounds 301a and 301b have the same potential difference and are unified regardless of analog or digital circuits. Therefore, when this model is connected with a serial communication cable, the signal input to each pin is input to and processed by the MAX232C ICs 203a and 203b in the same manner as the existing signal processing except for the ground terminal. The ground pins on the connectors 207a and 207b are connected to the communication-only grounds 301a and 301b provided in the respective devices, so that both devices are connected to substantially the same ground.

In addition, the microcontrollers 201a and 201b, the buffers 202a and 202b, the MAX232C ICs 203a and 203b, and the respective ground terminals for grounding general analog circuits and digital circuits are the same as in the existing system. .

That is, when a physical communication connection between two models equipped with an analog-to-digital conversion circuit is required, the communication lines (Tx, Rx) are connected by cross between these models in the same way as the conventional connection method, and the communication ground lines are connected to the respective devices. It is connected to the communication-only ground (301a, 301b) provided is processed. Therefore, it is possible to prevent data loss and abnormality caused by the potential difference that can occur in the existing communication ground in advance.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

As described above, according to the present invention, when designing a communication ground separately in a circuit design having an analog-to-digital conversion path, there is an effect of preventing communication errors that may occur during communication between models.

Claims (3)

In a device capable of data communication between heterogeneous equipment including an analog-to-digital conversion circuit, A connector including a ground terminal; A MAX232C IC that adjusts a transmission / reception level of data received from the connector; A buffer in which the data is temporarily stored; A microcontroller in which the data is processed; An analog ground to which the internal analog circuit is grounded; A digital ground to which internal digital circuits are grounded; And And a communication-only ground connected to the ground terminal in the connector and used only for connection with other external equipment. delete delete

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