CN204423035U - A kind of DT-CM128 bus acquisition monitoring device - Google Patents

Abstract

The utility model provides a kind of DT-CM128 bus acquisition monitoring device, main frame core is made up of STM32F407 32 arm processors of Cotex-4 kernel, peripheral circuit comprises isolation 485 interface, Ethernet interface, dual path isolation CAN interface, 7 inches of interactive touch display screens, 4 line state pilot lamp, 18, tunnel, 485 stacks number setting toggle switch, 18, tunnel 485 communication port setting toggle switch is formed.The application can be all compatible by analog quantity, digital data acquisition module, CAN analog quantity, CAN digital quantity simultaneously by host process data, stable operation after not conflicting, do not incur loss through delay and support multiple CAN analog quantity, CAN digital quantity to access.

Description

A kind of DT-CM128 bus acquisition monitoring device

Technical field

The utility model relates to a kind of DT-CM128 bus acquisition monitoring device, and relate to information, sensing acquisition field, particularly a kind of analog quantity based on CAN bus and digital module gather main frame.

Background technology

CAN bus is one of most widely used fieldbus in the world, has many main websites and runs and the universal serial bus of dispersion arbitration and the feature of broadcast communication.In CAN bus arbitrary node can at any time on one's own initiative on network other node send information and regardless of primary and secondary, therefore can realize free communication between each node.CAN bus has high, the easy realization of traffic rate and a kind of fieldbus having formed international standard of the various features such as cost performance height, is applied to various fields at present.Extensively adopt the product produced of CAN technology more single at present, such as analogue collection module, digital data acquisition module.Not having one can by both all compatible collecting unit.

Summary of the invention

Goal of the invention: the utility model provides a kind of DT-CM128 bus acquisition monitoring device, its objective is the incompatible problem existing for solution mode in the past.

technical scheme: the utility model is achieved through the following technical solutions:

A kind of DT-CM128 bus acquisition monitoring device, is characterized in that: this device comprises CPU, Phototube Coupling unit, analog input channel, CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface; Analog input channel connects Phototube Coupling unit by A/D converting unit, and Phototube Coupling unit connects CPU, and CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface are all connected to CPU, CAN controller have CAN interface.

advantage and effect:

The utility model provides a kind of DT-CM128 bus acquisition monitoring device, main frame core is made up of STM32F407 32 arm processors of Cotex-4 kernel, peripheral circuit comprises isolation 485 interface, Ethernet interface, dual path isolation CAN interface, 7 inches of interactive touch display screens, 4 line state pilot lamp, 18, tunnel, 485 stacks number setting toggle switch, 18, tunnel 485 communication port setting toggle switch is formed.

Main frame has two-way CAN, the maximum support in every road 32 CAN analog modules and 32 CAN digital modules, and CAN analog node ID range of distribution is: 1-32; CAN digital nodes ID range of distribution is: 33-64.Single channel CAN node ID has uniqueness, and two-way CAN module node ID can repeat.Maximum 256 road analog inputs can be realized, 256 railway digital amount inputs, the monitoring that 256 railway digital amounts export.It can be all compatible by analog quantity, digital data acquisition module, CAN analog quantity, CAN digital quantity simultaneously by host process data, stable operation after not conflicting, do not incur loss through delay and support multiple CAN analog quantity, CAN digital quantity to access.

accompanying drawing illustrates:

Fig. 1 is structural representation of the present utility model;

Fig. 2 is hardware structure diagram;

Fig. 3 is process flow diagram of the present utility model.

embodiment:below in conjunction with accompanying drawing, the utility model is further described:

As shown in Figure 1, the utility model provides a kind of DT-CM128 bus acquisition monitoring device, and this device comprises CPU, Phototube Coupling unit, analog input channel, CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface; Analog input channel connects Phototube Coupling unit by A/D converting unit, and Phototube Coupling unit connects CPU, and CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface are all connected to CPU, CAN controller have CAN interface.

On-the-spot various sensors are controlled owing to being distributed in, the output of transmitter can be analog quantity, also can be digital quantity, in order to these are multi-form, dissimilar signal can by based on the controller of CAN bus or host computer identify, the function that therefore will complete based on the data acquisition module of CAN bus is divided into two aspects: be on the one hand the continuous print analog input signal of the unknown is converted to the digital signal that microcomputer can receive, i.e. analog data collection, by field digital sensor on the other hand, digital signal or the digital quantity I/O signal of what the equipment such as transmitter exported follow a certain protocol format convert the information meeting CAN bus protocol to, i.e. digital data collection.Its specific implementation functional diagram is as shown in Fig. 1:

From Fig. 1, for analog data collection part, multichannel analog signals enters the input end of A/D converter by analog input channel, A/D converter starts to change multichannel analog signals one by one under the control of microcomputer (i.e. CPU), and the result of conversion is read in CPU, when one takes turns after data convert, judge that whether each road transformation result is reasonable, necessary process is carried out to rational result, then data are write data layout that CAN microcontroller converts CAN agreement to be sent in bus by its interface and to process further or other modules for host computer.And for digital data collecting part, this module mainly converts the data layout of CAN protocol requirement to by from controlling the on-the-spot data message sent with RS-232 protocol form and is sent to CAN bus for host computer and other modules.Because this data acquisition module is with CPU, it is a kind of smart machine of Microcomputer, preliminary process can be done to the data collected and complete certain control, display task, therefore also extend Multipath digital quantity input and output on that module and carry out the interface of direct serial communication with other single-chip microcomputers.Whole module can realize the collection to field data, carries out the functions such as communication to the display of equipment state, warning and field apparatus and host computer.

According to the function that the data acquisition module based on CAN bus will realize, its hardware circuit implementation is as shown in Fig. 2:

From Fig. 2, based on the data acquisition module of CAN bus with single-chip microcomputer SST89C54 for kernel processor chip; SST89C54 single-chip microcomputer is the derivatives of MCS-51 series monolithic.It is completely compatible with standard 8052 single-chip microcomputer in resource in order set, hardware configuration and sheet, just increases the capacity of internal program memory Flash.Built-in 20K ROM, program space surplus is large, facilitates the software upgrading of system, and the built-in EEPROM of SST89C54, and WatchDog Timer, with low cost, reliability is high.Whole hardware circuit implementation is made up of four parts:

1) CAN bus interface circuit: be made up of SJA1000 and 82C250, the operation of SST89C54 to SJA1000 is equivalent to the operation of external RAM, its P0 mouth meets the AD0 ~ AD7 of SJA1000, ALE ,/WR ,/RD, P2.4 end meet the ALE ,/WR of SJA1000 respectively ,/RD ,/CS hold, in addition the look-at-me end/INT of SJA1000 connect SST89C54 /INT0 end, make SST89C54 to receive and dispatch various information.CAN bus transceiver 82C250 provides the interface between CAN controller and physical bus, provides differential transmission and the receiving ability of bus, antijamming capability, and signal can fartherly be transmitted more reliably.Its TXD, RXD end is by high-speed light every TX0, RX0 of meeting SJA1000 respectively, and two output terminal CANH with CANL are connected with CANH and CANL of physical bus respectively.

2) A/D change-over circuit: realized by 11 tunnel analog/digital conversion chip TLC2543, P1.0 ~ P1.3 pin of SST89C54 respectively with TLC2543 /CS, CLOCK, DATA IN with DATA OUT is connected, by these connect, SST89C54 can control A/D change opportunity, select ALT-CH alternate channel, polarity; When after A/D EOC, TLC2543, by EOC pin, receives data with the form of interrupting notice SST89C54.Wherein TLC2543 is CMOS 12 bit switch electric capacity Approach by inchmeal A/D converter.There is rapid translating and general control ability.Sample-hold circuit is provided with in sheet.

3) RS-232 protocol conversion circuitry: SST89C54 is connected by the respective pin of serial ports TXD, RXD and MAX232, when SST89C54 need by from collection in worksite to data or communicate from the information that the data that CAN bus receives convert RS-232 protocol format to field apparatus or other modules time, directly can send information to MAX232 by serial ports TXD, RXD, be completed the conversion of data layout by chip MAX232.This part also extends serial communication circuit simultaneously, can realize carrying out serial communication with other equipment by the isolation of high speed optoelectronic isolator.

4) multichannel imput output circuit: because the data acquisition module based on CAN bus can directly be connected with multiple analog amount or digital quantity equipment, and inside is with CPU, there is certain data processing and control ability, so when module need the I/O of collection site measure information or needs carry out showing according to result, report to the police, control time, by by P1.4-P1.7 and high-speed light every the multichannel imput output circuit realization formed.

In addition, in order to meet the needs of data access and process, the data memory space (RAM) of 8K in circuit, is also extended.

Based on the process flow diagram of the data acquisition module of CAN bus as shown in Fig. 3:

By flow diagram, SST89C54 first carries out initialization to self, then immediately initialization is carried out to set up the communication linkage between this data acquisition module and CAN bus as early as possible to SJA1000, wherein a more crucial part in this Software for Design to the initialization of SJA1000, the baud rate of communication, AMR, ACR, OCR, CDR are set under being mainly included in reset mode, write control register command word etc. under common-mode.Wherein to determine according to the actual requirement of network system and site technique the content write in ACR, AMR register, and relevant with the message identifier that will send; The content of BTR0, BTR1 register can the uniquely communication baud rate of certainty annuity and synchronous redirect width, so the content of these two registers of all nodes in whole system must be identical, otherwise cannot communicate; The way of output of CAN controller can be determined to the operation of OCR, and the configuration of output driver needed for the level logic setting up CAN bus request.

After the connection setup of CAN bus, SST89C54 just starts collection site data, analog quantity before this, then be digital quantity, to in the data acquisition of analog quantity, the error brought to reduce external disturbance has also carried out elimination Error processing, mainly comprises and judges whether data exist super large error, average as measures such as sampled values, to reduce systematic sampling error to continuous several times data obtained of sampling.After having collected on-the-spot various data, CPU also will carry out data processing, and mainly comprise and the data collected are carried out assembling, unpacking packing, simple data operation, makes comparisons with setting value; Judge the bound whether on-site parameters normally works beyond equipment, the need of display device state or warning, as needs then carry out showing or reporting to the police; Judging whether to need to send data in CAN bus, then will carry out the conversion of different data format as needed, when needing to send the data more than 8 bytes toward CAN bus, also will divide multiple Packet Generation by the algorithm designed in advance.

Facts have proved that the data acquisition module based on CAN bus has sampled data renewal speed fast (10 milliseconds), conversion accuracy high (± 0.5%), transfer linearity error little (± 1LSB Max), traffic rate is high, strong anti-interference performance, error rate is extremely low, the features such as transmission citing is far away, can complete the collection of field data well and carry out simple data processing and data communication, the system be made up of this generic module is particularly suitable for site environment more complicated, the dcs that requirement of real-time is high, and it is cheap due to it, have a wide range of applications in automatic field.

Claims (1)

1. a DT-CM128 bus acquisition monitoring device, is characterized in that: this device comprises CPU, Phototube Coupling unit, analog input channel, CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface; Analog input channel connects Phototube Coupling unit by A/D converting unit, and Phototube Coupling unit connects CPU, and CAN controller, R232 interface circuit, serial communication interface and multichannel I/0 interface are all connected to CPU, CAN controller have CAN interface.