1 Introduction

With the rapid development of management dosage automation, dosage management concepts quickly into the automobile manufacturing industry. For an automobile manufacturing enterprise how to efficiently and orderly organization of each production workshop, each material in a timely manner to meet the specified measurement requirements is very important. Dedicated to the modern production site on the flow, material, quality, equipment measurement and monitoring information feeding system, is a flexible automated batching control system. The system can not only make smooth and timely, to realize the production of the minimum inventory, but also can make managers timely understanding of the whole enterprise's production and condition, so as to provide a basis for the enterprise feeding management decision-making.

INTERBUS field bus was launched by PhoenixContact in 1990, mainly used in automotive industry, tobacco industry, process automation, etc. IN-TERBUS is an international standard bus for I/O, with its constant transmission rate of 2M and data transmission mode of aggregate frame, which ensures the reliability of data transmission. The constant transmission rate of 2M and the data transmission method of aggregate frame ensure the reliability of data transmission, which makes the data exchange between loading system and field I/O devices have high real-time, and is internationally recognized as a high-speed bus. INTERBUS has powerful bus configuration, monitoring and fault diagnosis functions, so INTERBUS bus has good maintainability and high reliability. Therefore, INTERBUS has unique advantages and attraction in automobile production system.

2 System hardware design

Weighing and feeding system hardware consists of three parts: management layer, control layer and field layer. The management layer is an industrial computer (upper computer), as a human-machine interface, the industrial computer through the configuration king software and the control layer to exchange data. The control layer consists of IBSISAFC/I-T, a fieldbus control board from PHOENIXCONTACT, which is directly inserted into the ISA slot of the main board of the industrial control machine, and it can realize data acquisition, program control of the equipment layer as well as information exchange with the management layer. The field layer consists of call answering system and display system. The call answering system adopts PHOENIXCONTACT's bus coupler BK module IBSIL24BK-T/U, digital input/output DIO module IBIL24DO16 and IBIL24DI16, serial communication module IBILRS232, on-site FLS module FLSIBM12DIO8/ 8M12 and buttons. 8M12 and buttons; display system consists of LED display, light box. The structure of the whole automatic dosage system is based on the structure of the IN_TERBUS system, in addition to the centralized diagnostic display on the bus control board, each module dispersed in the system also has a corresponding display of the system operating status, through the diagnostic display, the operator can get the status of the INTERBUS system without using any other tools. Therefore, the whole INTERBUS system has good system maintainability.

3 System Software Design

The programming software of the weighing and mixing system adopts the PCWORX software in line with the IEC1131-3 standard, including the configuration software SYSTEMWORX and the programming software PROGAMWORX. The control program adopts the hierarchical structure and the modularization programming idea, and the lower module is called by the upper module, and the control, serial communication and online communication are realized at the highest level through the design of the basic function modules of each level. Realize control, serial communication and online diagnosis functions. The communication module, main control function module and online diagnosis module are introduced below.

3.1 Communication module

The dosage communication module is programmed with the structured text language provided by PCWORX and is responsible for sending information to the peripheral device display. The communication module mainly calls the peripheral equipment communication function blocks provided by PCWORX: PCP_CONNECT (communication connection), PCP_WRITE (output to peripheral equipment) and STRING_TO_BUF (string transfer to buffer). As the information sent to the peripheral device is relatively long, the string to be displayed plus the identification code at the beginning of a total of 50 bytes, in order to prevent the data behind from overwriting the data in front and to ensure the reliability of the data being sent, we call the STRING_TO_BUF function block provided by PC_WORX, which first writes the identification code and the string to be displayed into a data buffer in turn, combining them into a 50-byte string, and then writes them into a 50-byte string, which is then transmitted to the data buffer. 50-byte string, and then call the PCP_WRITE function block to send the information to the peripheral device.

3.2 Main control function module

The dosage master control function module adopts ladder diagram programming, using PC_WORX internal function module TON (delayed on module), R_TRIG (rising edge trigger module), F_TRIG (falling edge trigger module), GE (comparison module), CTU (counting module). AND and OR to realize the following functions: according to the production requirements, when the production line needs to feed a certain material, the production worker presses the control button on the corresponding workstation, the bus controller sends the name of the material through a communication metering module based on INTERBUS field bus according to the received process data information. According to the production requirements, when a material needs to be delivered on the production line, the production worker presses the control button on the corresponding workstation, the bus controller sends the name, workstation number, quantity and other information of the material to the LED screen display through a communication metering module based on the INTERBUS field bus according to the process data information received, and at the same time starts the music ringing and lights up the lights corresponding to the material on the workstation and the light box. Warehouse staff get the information, press the corresponding button under the light box indicator to answer, then the light box on the light of the material on the indicator light off, indicating that the information is confirmed to have started feeding. According to the confirmed information, the bus controller will turn the indicator light above the button of the workstation from normal light to flashing state, indicating that the material is being fed. When the material arrives at the called station, the operator restores the button to the disconnected state, and the indicator light goes out, indicating the end of the material distribution process.

3.3 Online Diagnostic Module

The standard registers in the dosing INTERBUS bus controller IBSISAFC/I_T provide information on the status of the bus operation, and the bus system can also be operated through the control program. The standard registers in the bus controller include the Diagnostic Status Register, Diagnostic Parameter Register, Standard Function Start Register, Standard Function Status Register and Standard Function Parameter Register. The addresses of the registers can be set in the input or output address area of the weighing and dosage system using the PCWORX configuration software for ease of application in programming. The Diagnostic Status Register is one word long, with each bit reflecting an aspect of the bus system's operating status. The Diagnostic Parameter Register provides more detailed information for the status bits of the Diagnostic Status Register. The Diagnostic Parameter Register provides the error location when peripheral device failures and bus errors occur, and the Diagnostic Parameter Register provides the error code when controller and bus errors occur.

The online diagnostic module of the dosage system is programmed in ST (Structured Text) language and encapsulated after programming into the function module FCDIAG with diagnostic and self-starting functions. The module takes as input the diagnostic status registers and the diagnostic parameter registers, and after processing assigns the diagnostic information to the global external variables ERR_DIAG_STATUS and ERR_DI_AG_PAPA, which can be transmitted to the host computer for processing through the OPC system. the bus stops running when there is a fault in the INTERBUS unity. The self-starting function of the module can automatically detect whether the fault is cleared or not. Once the fault has been detected and cleared, the bus will start running through the standard function startup register, and the weighing and dosage system will be restored to the normal operation state automatically.

4 monitoring software development with configuration king

OPC (OLEforprocesscontrol) is the process control object links and embedded automatic dosage system, OPC to component object model and distributed component object model automatic dosage system based on the client / server model, defines a set of COM objects and their interface standards, is a kind of industrial control and production automation field in order to connect the data source (OPC) and the data user (OPC) INTERBUSOPCServer is an OPCServer specially developed by Phoenix for the INTERBUS system, through which Configuration King can easily communicate with the field devices of INTERBUS. The development of monitoring software on the upper computer with the configuration king can realize the management and monitoring of the whole system by the management. The following describes how the monitoring software realizes the following main functions.

4.1 Generate history database

First of all, define the I/O discrete variables in the data dictionary of Configuration King and the corresponding variables in the INTERBUS bus to connect, for example, define the I/O discrete variable "Call Button 01" in the data dictionary and the variable "ASB01" in the weighing and dosage system of INTERBUS bus to connect, so when calling materials, the variable "Call Button 01" changes from 0 to 1, and when ending the call, the variable "Call Button 01" changes from 1 to 1. "Connected, so when the call material "call button 01" variable from 0 to 1, when the end of the call "call button 01" variable from 1 to 0; and then defined "call button 01" variable data Then, the data change command language for the "Call Button 01" variable is defined, and various time information related to the material is saved in an intermediate variable in the data change command language program, and counted in the data change command language of the system preset variable "$Seconds", which is used as a software timer. When the end of the call, use SQLInsert (DeviceID, ″HJJL″, ″Call Record″) function to write all kinds of information into the database, the parameter DeviceID in the function is the ID number generated by Configuration King through the connection of ODBC data source and the database, HJJL is the name of the form template, and the call record is the name of the record body.

4.2 Real-time monitoring

Each graph in the real-time monitoring screen of the weighing and dosing system corresponds to the corresponding material, and the attributes, position and size of the graph can be changed by defining the animation connection to form the effect of animation. Therefore, the real-time monitoring screen can display the demand for materials at each station and the flow status of various materials in the production process in real-time animation.

4.3 Report Generation and Printing

With KVDBGrid control and the generated history database connection, it can generate and print various reports about materials, including daily feeding report, emergency feeding report, delayed feeding report and various query reports, which can be used as the basis for enterprise management decisions and assessment of employees. And commands can be used to realize the display, query and printing of running data, part of the program code is as follows:

4.4 Online fault diagnosis

Firstly, the fault type, fault code and corresponding detailed information as well as the treatment method are saved in the database. Once a fault occurs in the INTERBUS, the diagnostic program according to the global external variables ERR_DIAG_STATUS and ERR_DIAG_PAPA sent by the INTERBUSOPCServer can immediately obtain the diagnosed fault type, fault location and fault code, and apply the database to program the automatic dosage system, which can display the detailed information of the fault in real time as well as the Handling methods, maintenance personnel based on this information to make rapid processing, and as soon as possible to restore the weighing and batching system operation to improve production efficiency. Therefore, online fault diagnosis improves the reliability of INTERBUS weighing and batching system.

4.5 Network real-time information and historical data distribution

Through the network, real-time monitoring screen can be released on the network, and the data of historical database can also be transmitted on the network. Each management department of the company can carry out remote monitoring and management as well as realize data resource sharing of the database through Internet, which provides a powerful automatic dosage system support for improving the production efficiency and management level of the company.

5 Conclusion

The material call in the production process is realized by INTERBUS field bus, and the monitoring software is designed in the upper computer by using configuration king, so that the whole system has the function of fault diagnosis and network release. The online fault diagnosis function in the weighing and batching system improves the reliability of the system operation; the network release function facilitates the monitoring and management of the management. Since the system was put into operation, it has been running well and met the expected control requirements.