Application of SIMATIC IT historian in the production of cellulose diacetate for tobacco

Original reproduced from: http://www.soft6.com/tech/5/54287.html

This paper introduces the application of Siemens MES core product simatic IT historian Real-time database and client tool in process production. The application project, known as the "Filament tube control system", historian as a bridge, connecting the PCS7 control system down and connecting the ERP up. As the local application content of MES, it has obvious effect and good effect.


1. Project background

Nantong Cellulose Acetate Co., Ltd. (hereinafter referred to as NCFC) is a large-scale industrial enterprise which integrates thermoelectric, chemical and textile industry, and the production area is divided into 3 pieces according to its function, namely: the silk beam area, the vinegar slice area and the common engineering area, the main products are cellulose acetate tow and its raw material diacetate tablets.

In 2004, NCFC began the four-phase expansion project, the scale of the expansion will be the original one times, the expansion of the wire bundle area is an important part of the four phase project. The filament tube control system strengthens the function of the PCS7 control system from improving the overall management of the workshop production, it tracks and participates in the production control of each link in the whole assembly line, makes the chemical reaction of raw material to the quality control of the semi-finished product and the packing and warehousing of the finished products to realize the whole integration automation. It also submits the relevant data information to the ERP system.

2. System architecture

The filament production process is a continuous production process, and its bottom control system is Siemens PCS7. The PCS7 HMI system uses the server client approach, consisting of two pairs of redundant WINCC servers and multiple WINCC clients, with a total of approximately 10,000 I/OS. The filament tube control system communicates with the PCS7 system on one hand through the OPC interface, obtains the real-time process data and archives, on the other hand controls the correct execution of the business process, ensuring the production efficiency and quality. From the functional points, the filament tube control system includes work order management, barcode label management, physical and chemical testing, packaging and transportation scheduling, finished product testing, warehousing, process data reporting, quality data statistical analysis, comprehensive data query subsystem. The overall system structure diagram is as follows:

System General structure diagram

3. Feature Introduction

3.1 Process data acquisition and archiving

The data collection of production process is the information source and foundation of MES system and plant-level production Management Information System (ERP/MIS), in this project, realizes the pulping, spinning, curling, drying, swinging wire, packing, Transmission and other complete production processes for the production process and process data collection (about 3,000 points), for the equipment can not be directly obtained from the control system maintenance, quality sampling samples and other information, through the manual input method to ensure that the MES system can obtain a complete production management information. In the field of data real-time interaction, data storage and post-processing, the filament tube control system has high requirements:

Real-time sex
The system needs to interact with the process control system in real time, for example:

1. The process signal is triggered to generate the product's water package number (PackageID).
2. Some laboratory data need to be directly written to the process Control system as a reference value for control.
3. The conveying system needs to be dispatched according to the production situation.

Massive data storage and querying
1. A large amount of process data requires a compressed archive.
2. The user can obtain historical data of any time period in the shortest time.

Further analytical processing of the data is required.
1. Further analysis and processing of quality data, such as quality stability analysis, SPC analysis and so on.
2. The operation of equipment, standby and maintenance time statistics, analysis of equipment performance.
3. The problem product is traced according to the product serial number and the process list.

SIMATIC It historian is the solution we have been looking for in the first four phase of the project, and we have used it to replace the previous way of developing these functions, and have achieved very good results.

3.2 Production Management

Work Order Management
The work order defines the specifications of a product and the related process parameters. The work order is developed by the process engineer and approved by the management staff. The work order is executed for a production line, and the corresponding process parameters are issued to the Process Control system, and the product specifications and batch numbers are replaced by the data defined in the work order. Sometimes, significant process adjustments require parking execution, at which time a work order pre-execution time can be set, and the system will automatically fine-tune the production cycle for each production unit, allowing the majority of production units to complete the current cycle near the pre-execution time, thus significantly reducing the time to park.

Work orders are linked to the Process control system and the important link of the management system, through each product serial number can be queried to the corresponding work order to obtain the data of important equipment control parameters, for quality traceability provides a basis.

From the work order management system can be real-time query the production line is being carried out and will be executed work order situation.

Barcode generation
The product serial number in the filament tube control system is circulated in the business process in the form of barcode. The barcode information contains product specifications, lot numbers (defined in the ticket), production serial number, class number, and production date. When a product starts production, the system automatically generates barcodes and prints multiple copies, part of the product sample delivery laboratory for the laboratory system to read the sample production serial number, part will be shipped with the product to the back of the packaging, moisture detection and warehousing links.

Production sequence number is unique, it runs through the production process from semi-finished products to finished goods, and is the key index of quality monitoring and tracking.

Quality inspection
Operators can define the inspection items and sampling time of various types of products in advance. The system automatically generates a message prompt when the sampling time arrives. Laboratory personnel to test the sample after the input or system automatically from the laboratory equipment to collect test data, and according to the barcode scanner to read the product sequence to generate inspection records. Laboratory data generated by the latest test can be immediately displayed on each client, while the system can automatically judge the different, unqualified records will produce an alarm, so in the production line of personnel can obtain quality information in real time, in order to make timely adjustments to production.

Packing and conveying
Packaging system First has the function of conveying dispatch, it needs to automatically generate or manually set up the traffic dispatching task information and write to the PCS7 conveying system according to the production schedule of each production line. The conveying system will deliver the first or highest priority wire bundle to the specified baler packaging weighing. The packaging system automatically collects weight data from the weighing instrument and generates the Product factory label based on the product serial number read by the barcode scanner.

Finished goods warehousing
Finished goods storage System is the final inspection of the wire bundle package, the finished wire bundle data into the finished product library and submitted to the ERP system. The finished product library has the following features:
1) Provide the location management function. When the tow bag is stored in storage, it is convenient to find the location. The location can be pre-defined, when the wire bundle into the storage can be automatically corresponding to the location of the storage location.
2) provide personalized pick-and-pack function. When the wire bundle is out of the library, according to the user needs (the variety of the package, quality characteristics and the priority of each feature, etc.), automatically select the appropriate bundle package, at the same time to obtain the storage location of these packages.
3) Provide the data processing function of the tow package. The "Data modification" can be used to modify the gross weight and net weight of the selected bundle package, such as modification error or some other reasons; The original data of gross and net weight can be restored with "data recovery" to the selected bundle package.
4) Provide query package processing function. You can use the "question package" to make a question pack logo on the selected tow bag, and use the "Question pack processing" to process the thread bundle which has been marked with doubt, which can be processed into a genuine or scrap; You can use the "Question pack recovery" to restore the original data for the selected question pack.
5) Provide test package processing function. "Test Package Application" to the selected bundle of bags to the test package mark; "Test kit use" for each use of the test package record and net weight modification; "Test pack Recovery" restores the original data for the selected test package.

3.3 Quality Management

The concept of the filament tube control system embodies as follows: the quality management through the product "raw materials-manufacturing-after-sales service" always, to "source can be prevented, the process can be monitored, the results can be analyzed." That is, the product from production to sales of every aspect of the information into the control system, and by the control system monitoring, for any quality problems produced, can be controlled by the control system of the process analysis, to find the root cause of the problem.

SOURCE prevention
In the procurement of raw materials, auxiliary production facilities (public works), spinning to the finished product production process has a corresponding workshop work subsystem, these subsystems have a specific link of quality inspection function, can determine whether the quality of the link itself is in line with the requirements, the factors that may affect the quality of the source of prevention. The implementation of the precautionary principle is the core and essence of modern quality management.

At the same time, these subsystems are responsible for the detection, acquisition of quality data and key process parameters and other information to the server, in order to carry out a variety of related quality analysis. To ensure the integrity and accuracy of the original data, data acquisition and input have a "manual/automatic" mode, can be switched to each other, once the "automatic" mode of failure, the operator can manually input data by "manual" mode.

Process monitoring
In addition to the operation of each subsystem in the workshop, it is also responsible for monitoring the quality. For example: broken wire alarm system, raw material inspection, important parameters of public works, pulping/acetone data, material inspection and data, wire break information and packet moisture data, etc., this information on the one hand in the local position reflected in real time, on the other hand, the information will be integrated together, Real-time reflection in the central control room or other designated location, so that the quality of the production process is fully monitored.

Results analysis
Based on the complete process data and information, quality analysis means and methods are effective. Under the precondition of source prevention and process monitoring, the analysis of quality results is emphasized. To this end, the system will provide a variety of quality statistical analysis reports and professional quality analysis methods, and provide relevant multi-factor analysis function, so that the parameters of different time periods can be analyzed together.

4. Summary

The system has been put into normal operation on June 9, 2005 and has been fully affirmed by the users. The stability and efficiency of SIMATIC IT historian we have completed the application and development of the filament tube control system in a short time (from the arrival of Hisrorian product to the completion of the project only 3 months). It is really like a bridge, connecting the management and control layer, the process data report the first time reflected in front of the manager. At the same time, developers can not focus on the specific IT technology, but concentrate on the optimization of business processes.

Simatic It historian is only a member of the Siemens MES software family, simatic it provides a complete set of business and production process MES solutions, we believe that simatic it Mes will occupy a place in the informatization process of Chinese manufacturing enterprises and play its due role.

Quality analysis means and methods are effective. Under the precondition of source prevention and process monitoring, the analysis of quality results is emphasized. To this end, the system will provide a variety of quality statistical analysis reports and professional quality analysis methods, and provide relevant multi-factor analysis function, so that the parameters of different time periods can be analyzed together.

Application of SIMATIC IT historian in the production of cellulose diacetate for tobacco