With the development of the pharmaceutical industry in the direction of scale and the improvemen‍t of the pharmaceutical industry's requirements for output, control performance and equ✘ipment stability and reliability, more and more enterprises have owned o≈r began to consider purchasing high-speed tablet presses. As a major manufacturer of high-speed taπblet presses, this paper attempts to analyze and compare the electrical± control systems of high-speed tablet presses in the current ₽domestic market to help users understand and judge such machines.

According to the information we have, most of the electrical systems of high-speed tablet' presses produced in China now use the following three methods: single-chip microcomputer, industrφial control computer and programmable logic contro★ller (PLC). The following is a comparison of the performance of these three control systems, from w∑hich we can also understand the evolution and development of ←the electrical control system of the high-speed tablet press.

1. Single Chip Microcomputer

The so-called single-chip microcomputer system is the use of the current market sin<gle-chip CPU and other peripheral chips, according to different systβem design circuit board, the final design into a simple computer system, and on this basis€ design procedures to achieve the required control functions. This form was very popularα in China in the 1980 s, but due to its own reliability and other limitations, in addition× to the instrument is still used, the application in the industrial field has been graduallσy replaced by PLC.

Reliability of single-chip microcomputer: due to the mixed quality of single-chip microc¥omputer chips in the domestic market at present, a large part ofε them are inferior products screened out from abroad. in addition, the parameter dispersion of♦ other peripheral components (such as resistors, capacitors, etc.) is also very large. it♥ is impossible for products with small batches to undergo technicalδ processing such as screening and matching, so it is difficul®t for such products to achieve good consistency and high reliability, b♥ecause the parameters of any component deviates from the design requirements, the ₹system will be unstable. In addition, all devices are not industβrial-grade, anti-interference, especially anti-power interference ability is very we‌ak, and the domestic power supply is generally very poor, coupled with thλe tablet press frequency control of the power supply interference is very← large, therefore, more likely to cause instability of← the microcontroller system.

The scalability of the microcontroller: Because the circuit of the microβcontroller is specially designed according to certain€ functional requirements, it is necessary to redesign the circ™uit to add a function, and the corresponding procedures must be re designed. This increases the development cost and cycle time for adding functi↕onality.

Maintainability of the single-chip microcomputer: Once the single-←chip microcomputer system fails, it is difficult to diagnose the faulty components.± The easiest way is to replace the entire system, which increases‍ the maintenance cost.

Operation: At present, the operation of domestic single chip microcomputer syste₹m adopts self-designed keyboard, dial switch for setting data and L®ED for display. The whole panel is complicated and locked. Moreove≤r, in order to reduce the operation keys, one key is often used in design, so it is di™fficult for operators to operate without instructions. In particular, the fa<ult display can only display the fault code. Once a fault occurs, the operator must read the manua✔l to find the fault, and finally troubleshoot according to the instructions in the m↕anual, so that the troubleshooting time is relatively long. In s✘hort, such human-computer dialogue is not friendly enough.

Features: unreliable and cheap.

2. Industrial control computer

The so-called industrial computer system is the use of the current mar♥ket on the so-called industrial control computer system, on the basis of the design of the program© to achieve the design of the function. However, people in the industry know that ther©e is no essential difference between industrial control machines on the market and c≈ompatible machines assembled by themselves. First of all, the CPU, wh©ich is the heart of the computer, is of non-industrial grade as well as the compa>tible machine. The rest of the main components such as hard disk, memory,  display, etc. are of non-industrial grade. The only difference is that t÷he chassis has been reinforced. Due to its reliability and otδher limitations, this form is rarely used in industrial fields exc₩ept for a large number of occasions where it is not directly involved in cont←rol as a monitoring machine in factories.

Reliability of industrial control computer: because the main components of indus$trial control computer are not industrial grade, compared with αsingle chip microcomputer system, anti-interference, especially anti-power interference ability has® been improved to a certain extent, but the domestiαc power supply is very poor, and the frequency conversion speed re¶gulation of tablet press has great interference on tΩhe power supply, so it may also cause instability of the s↑ystem.

Scalability of industrial computer: to add a function, it is necessary to redesi<gn the corresponding program, while the programming of industrial computer is rel<atively complicated, which will increase the development cycle.

Maintainability of industrial control computer: onc★e the industrial control computer system fails, it is difficult to diagnose the faulty components, ≈so that the maintenance cycle increases, and non-professional personnel can not rep air, if the fault is caused by unreasonable program design, "due to the lack of appropriate debugging tools, it is al&so very difficult to find out the cause of the fault.

Operation: There is no difference between the operation of the industrial computer anπd the general computer, which has high requirements for the quality of the operator. The ave£rage worker will have a fear when he sees the computer. Although the operation interface÷ is friendly, it is still not easy to learn for those who are not fam↕iliar with the computer system.

Features: price in the middle, reliability improvement is not much.₹

3. Programmable Logic Controller (PLC):

The so-called PLC system is the use of the current market major industrial control manufactur₽ers of programmable controller, according to the requirements of t‌he selection of different modules, on the basis of the design program to achieve the design♠ function. This form is currently the most widely used in‌ the industrial field. The GZPK100 series high-speed rotary tablet press produced by ou≥r company adopts PLC control mode.

Reliability of PLC: The CPU used in imported PLC is anα industrial-grade special processor specially designed by the manuεfacturer. The rest of the components are also purcλhased directly from the manufacturer. After strict selection of industrial-grade components, i♥n addition, its power supply module is specially designed based on the experie€nce of industrial control of major companies. The anti-interfere¥nce capability, especially the anti-power interferen€ce capability, is greatly improved, even in the interference of ≈poor power supply and variable frequency speed regulation↑ can still work normally.

PLC scalability: to add a function as long as the corresponding increase in the m♦odule and modify the corresponding program, and PLC programming is relatively simp→le, so for the development cycle will be shortened.

PLC maintainability: PLC itself has a strong self-diag¥nosis function. Once the system fails, it is easy to diagnose the faulty components according to₹ self-diagnosis. Even non-professionals can repair it. ♥If the fault is caused by unreasonable program design, it is relatively simple to fi®nd out the fault because it provides perfect debugging too∞ls.

Operation: PLC operation using touch operation terminal, man-machine interface, fu×ll-screen display, the above design of a very detailed operation guide, even if the £first use, but also according to the prompt smooth operation, which reduces the requirements of≈ the operator, the general workers can quickly grasp. In addition, oπnce the system fails, the screen automatically switches to the failure prompt screen, prompting t∑he cause of the failure and the troubleshooting metho‍d. It can even display the location of the fault on the machine, and the maintenance personnel can∞ quickly eliminate the fault according to the prompt.

Features: The price is slightly more expensive tha↔n the first two controllers, with good reliability and simple operation.

In addition, the design, manufacture and installation of the electrical system of the GZPK100 h‍igh-speed tablet press adopts IEC standard, and the main electrical com'ponents are imported from famous foreign manufacturers, thus ↔increasing the reliability of the system. The system chip method adopts the combinaΩtion of batch chip and single value chip, and the single value chip is one ✔grade higher than the batch chip in terms of effect and technical difficulty.

The operation and display of GZPK100A high-speed tablet press are concentrated on •the man-machine interface. Except for the beginning of the≈ main power supply and the emergency stop button, no button operation is requi→red, which greatly reduces the influence of powder o×n electrical components and indirectly improves the reliability> of the electrical system. The protection level of the m→an-machine interface is IP67, which can resist various harsh environments. The design idea ↔of centralized operation display is more in line with GMP.