CN103226527A

CN103226527A - Multiple joint communication circuit based on RS232C standard

Info

Publication number: CN103226527A
Application number: CN2013101227037A
Authority: CN
Inventors: 张昔坤; 秦飞; 甘宜梧; 郭宣城
Original assignee: Biobase Biodustry Shandong Co Ltd
Current assignee: Biobase Biodustry Shandong Co Ltd
Priority date: 2013-04-10
Filing date: 2013-04-10
Publication date: 2013-07-31
Anticipated expiration: 2033-04-10
Also published as: CN103226527B

Abstract

The invention provides a multiple joint communication circuit based on an RS232C standard, which comprises an RS232C interface driver, an imitating selective distributor and a level conversion chip, and is characterized in that DTR and CTS of RS232C of a host computer are connected to the input end of the RS232C interface driver; TXD and RXD of RS232C of the host computer pass through the level conversion chip to be connected with the imitating selective distributor; TXD and RXD of a multichannel RS232C communication interface of a slave computer pass through the level conversion chip to be connected to the imitating selective distributor; and the output signal of the RS232C interface driver is connected to an address input end of the imitating selective distributor. The multiple joint communication circuit provided by the invention can be used for flexibly selecting a singlechip to carry on data interaction with the computer through circuit switching, the communication quality is high and the performance is stable, the chip adopted by the multiple joint communication circuit is cheap, the cost of the whole circuit is low, and the application and popularization are facilitated.

Description

Multinode communicating circuit based on the RS232C standard

Technical field

The present invention relates to a kind of multinode communicating circuit, in particular, relate in particular to the multinode communicating circuit that a plurality of single-chip microcomputers at a kind of various system works station are communicated by letter with control computer based on the RS232C standard based on the RS232C standard.

Background technology

Most computers all has based on RS232C standard serial communication interface, and the equipment of a lot of GPIB compatibilities also has RS232C standard serial communication interface, and computing machine can be finished communication and control to instrument and equipment by serial ports.Because low, the stable performance of this serial communication cost is also followed unified standard, thereby be widely used in the exchanges data of computing machine and external unit in the Engineering Control.But computing machine often comprises two at most based on RS232C standard serial communication interface; often can use a plurality of single-chip microcomputers in some instrument and equipments controls instrument; how to guarantee that computing machine and each single-chip microcomputer carry out reliable exchanges data, become problem that needs solve in the Engineering Control.

Summary of the invention

The present invention is in order to overcome the shortcoming of above-mentioned technical matters, and a kind of multinode communicating circuit of using when control computer and a plurality of single-chip microcomputer carry out exchanges data in the various system works station based on the RS232C standard is provided.

Multinode communicating circuit based on the RS232C standard of the present invention comprises RS232C interface driver, analog selection divider and level transferring chip; Its special feature is: the DTR in the RS232C communication interface of host computer, cts signal line are connected with the input end of RS232C interface driver, and the TXD in the RS232C communication interface of host computer, RXD data line are through being connected to after the level transferring chip on the analog selection divider; TXD in the multichannel RS232C communication interface of slave computer, RXD data line are through being connected to after the level transferring chip on the analog selection divider; The output signal of RS232C interface driver is connected to the address input end of analog selection divider, and the analog selection divider makes the multichannel RS232C of slave computer be communicated with the RS232C selectivity of host computer under the effect of address input end signal.

DTR, cts signal line in the RS232C communication interface of host computer are used to form two bits, so that host computer is selected to carry out communication with different slave computers, the RS232C interface driver is used for the RS232C level is converted into Transistor-Transistor Logic level.TXD, RXD signal among the host computer after level transforms and the RS232C of slave computer all are connected with the different port of analog selection divider, the analog selection divider realizes that host computer communicates with different slave computer under the control of RS232C interface driver output signal.

Multinode communicating circuit based on the RS232C standard of the present invention, RS232C interface four line drives that described RS232C interface driver is model MC1488, described analog selection divider is two 4 tunnels analogy selection/dividers of model HEF4052B, and the model of described level transferring chip is ADM233L.

Multinode communicating circuit based on the RS232C standard of the present invention, DTR in the RS232C communication interface of described host computer, cts signal line are connected to 2A, the 3A input end of MC1488 chip respectively, and the TXD in the RS232C communication interface of host computer, RXD data line are connected to ZA, the ZB input end of HEF4052B respectively after the conversion of ADM233L; The RS232C of slave computer is three tunnel, three road RS232C are connected to HEF4052B respectively after the conversion of ADM233L different passages.

The invention has the beneficial effects as follows: the multinode communicating circuit based on the RS232C standard of the present invention, be converted into Transistor-Transistor Logic level by RS232C level, be connected to again on the analog selection divider the TXD among the RS232C of host computer and a plurality of slave computers, RXD data line; DTR in the RS232C interface of host computer, cts signal line are connected to the control end of analog selection divider as control signal, have realized the selective communication of host computer and slave computer effectively.The advantage of the multinode communicating circuit based on the RS232C standard of the present invention has: (1) by circuit switch can select flexibly computing machine and which single-chip microcomputer carry out data alternately, and the high communication quality, stable performance; (2) price of chip of the present invention is all lower, and the cost of entire circuit is very low, is convenient to application and universal.

Description of drawings

Fig. 1 is the schematic diagram of multinode communicating circuit of the present invention;

Fig. 2 is the circuit diagram of multinode communicating circuit of the present invention.

Among the figure: 1 host computer, 2 RS232C interface drivers, 3 level transferring chip, 4 analog selection dividers, 5 level transferring chip, 6 first via RS232C, 7 the second road RS232C, 8 Third Road RS232C.

Embodiment

The invention will be further described below in conjunction with accompanying drawing and embodiment.

As shown in Figure 1, provided the schematic diagram of the multinode communicating circuit based on the RS232C standard of the present invention, it comprises RS232C interface driver 2, level transferring chip 3, analog selection divider 4, level transferring chip 5, first via RS232C, the second road RS232C and Third Road RS232C; RS232C interface driver 2 is used for the RS232C level of the DTR of the RS232C of host computer 1, cts signal is converted into Transistor-Transistor Logic level, so that produce the control port that control signal inputs to analog selection divider 4.

Level transferring chip 3 and level transferring chip 5 can adopt same chip, the conversion in realization host computer 1 and the slave computer 9RS232C communication interface between RS232C level and the Transistor-Transistor Logic level.The TXD of the multichannel RS232C communication interface of slave computer 9, RXD signal are connected on the analog selection divider 4 after transforming, under the control action of RS232C interface driver 2 output signals, optionally be communicated with TXD, RXD in the RS232C communication interface of host computer 1.Like this, promptly realized communicating by letter of host computer 1 and a plurality of slave computers 9 effectively.Slave computer 9 can adopt single-chip microcomputer.

As shown in Figure 2, provided the circuit diagram of multinode communicating circuit of the present invention, the chip that RS232C interface driver 2 adopts is MC1488, and level transferring chip adopts ADM233L, and it is HEF4052B that analog selection divider 4 adopts the model of chip.

The RS232C interface of shown host computer 1 is connected to the RS232C interface DB9 of multinode communicating circuit by Serial Port Line, DTR wherein, cts signal are exported by signal A1, the A0 that level transferring chip MC1488 is converted to Transistor-Transistor Logic level, signal A1, A0 receive address input end A1, the A0 of two 4 tunnels analogy selection/divider HEF4052B, be used for controlling public I/O passage ZA, ZB with which independently the I/O passage be connected.

R4in and T1out that transmission signal TXD that serial ports of computers transmits and received signal RXD are connected to level transferring chip ADM233L, through the Transistor-Transistor Logic level signal after the level conversion is R4out and T1in, R4out, T1in link to each other with public I/O passage ZA, the ZB of two 4 tunnels analogy selection/divider HEF4052B respectively, and signal TXD, the RXD that final host computer serial ports transmits is sent to public I/O passage ZA, the ZB of chip HEF4052B after level conversion.

The system of setting up departments has three control circuit boards in the workstation, can represent with A circuit board, B circuit board, C circuit board respectively, the realization of each circuit board function is all finished by a single-chip microcomputer, forms first via RS232C, the second road RS232C and Third Road RS232C three road connections.The serial ports pin TXD of A circuit board and RXD are connected to the J7 of multinode communicating circuit by winding displacement, link R1in and the T2out of chip ADM233L then respectively, become the R1out and the T2in of Transistor-Transistor Logic level after level conversion, R1out, T2in finally are connected to independently I/O passage Y0B and the Y0A of chip HEF4052B.The serial ports pin TXD of B circuit board and RXD are connected to the J8 of the commutation circuit of communicating by letter by winding displacement, link R2in and the T3out of chip ADM233L then respectively, become the R2out and the T3in of Transistor-Transistor Logic level after level conversion, R2out, T3in finally are connected to independently I/O passage Y1B and the Y1A of chip HEF4052B.The serial ports pin TXD of C circuit board and RXD are connected to the J9 of the commutation circuit of communicating by letter by winding displacement, link R3in and the T4out of chip ADM233L then respectively, become the R3out and the T4in of Transistor-Transistor Logic level after level conversion, R3out, T4in finally are connected to independently I/O passage Y2B and the Y2A of chip HEF4052B; Wherein the GND of the serial ports pin of A, B and C circuit board all is connected to the power supply ground of multinode communicating circuit.

The transmission signal TXD of host computer serial ports is sent to the public I/O passage ZA of chip HEF4052B, and ZA with which passage among passage Y0A, Y1A, the Y2A links to each other, and the signal DTR that is transmitted by serial ports of computers, the logic level of CTS determine jointly.In like manner, the received signal RXD of serial ports of computers is sent to the ZB of chip HEF4052B, and linking to each other with which passage among passage Y0B, Y1B, the Y2B as for ZB also is to be determined by signal DTR, CTS.If the logic level of DTR, CTS is " 00 ", ZA, ZB can link to each other with passage Y0A, Y0B respectively so.If the logic level of DTR, CTS is " 01 ", then ZA, ZB can link to each other with passage Y1A, Y1B respectively.If the logic level of DTR, CTS is " 10 ", then ZA, ZB can link to each other with passage Y2A, Y2B respectively.

Because ZA, ZB are connecting the TXD and the RXD of serial ports of computers in logic, YnA, YnB are connecting the serial ports pin RXD and the TXD(n=0,1,2 of n circuit board in logic respectively), the logic level state that transmits signal DTR, CTS by serial ports of computers decides the value of n, has so just realized the data interaction by the RS232C communication interface of computing machine and polylith control circuit board.

Claims

1. the multinode communicating circuit based on the RS232C standard comprises RS232C interface driver (2), analog selection divider (4) and level transferring chip; It is characterized in that: the DTR in the RS232C communication interface of host computer (1), cts signal line are connected with the input end of RS232C interface driver, and the TXD in the RS232C communication interface of host computer, RXD data line are through being connected to after the level transferring chip (3) on the analog selection divider (4); TXD in the multichannel RS232C communication interface of slave computer (9), RXD data line are through being connected to after the level transferring chip on the analog selection divider; The output signal of RS232C interface driver is connected to the address input end of analog selection divider, and the analog selection divider makes the multichannel RS232C of slave computer be communicated with the RS232C selectivity of host computer under the effect of address input end signal.

2. the multinode communicating circuit based on the RS232C standard according to claim 1, it is characterized in that: described RS232C interface driver (2) is RS232C interface four line drives of model MC1488, described analog selection divider (4) is two 4 tunnels analogy selection/dividers of model HEF4052B, and the model of described level transferring chip is ADM233L.

3. the multinode communicating circuit based on the RS232C standard according to claim 2, it is characterized in that: the DTR in the RS232C communication interface of described host computer (1), cts signal line are connected to 2A, the 3A input end of MC1488 chip respectively, and the TXD in the RS232C communication interface of host computer, RXD data line are connected to ZA, the ZB input end of HEF4052B respectively after the conversion of ADM233L; The RS232C of slave computer is three tunnel, three road RS232C are connected to HEF4052B respectively after the conversion of ADM233L different passages.