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PCI-based control of the laser marking system

Print View , by: iSee ,Total views: 10 ,Word Count: 1669 ,Date: Wed, 24 Jun 2009 Time: 11:23 PM

0 Introduction

As a result of excellent monochrome laser, the coherence, direction, and at the same time a high energy density, it is widely used in materials processing. Marking items as the process of security, accuracy, and environmental protection needs of the increasing laser marking equipment, especially laser flying marking equipment widely cited. Here, the principal introduced the laser marking control system hardware and software design, analysis focused on PCI-based circuit design of the control card of the key issues, at the same time introduced the marking of the main functions of the software. The control system has a 4-channel 16-bit D / A output, 3-way 16-bit counter, 4-channel DI / DO, 1 Road, laser power control PWM output. System performance in the application of stable, full-featured, have been applied to industrial production.

1 laser marking control card design

Laser marking system control card is the hub of the entire control system, connected to the control software and implementing agencies. Control card structure as shown in Figure 1, including those based on PCI bus interface control circuit, the local logic control circuit and functional circuit components, such as 3.

PCI-based control of the laser marking system

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PCI interface circuit for the realization of the local PCI bus to the logic of the logic of conversion. System uses a PCI bus control PLX chip companies as PCl9052 interface chip, the chip configuration E2PROOM as HT93LC46. Because of the rich interface chip features to simplify the interface design, so that work on the local logic design, using WDM drivers, the realization of computer integrated management of the equipment. Local logic control circuit to achieve local bus IP core of the decoding and functions of the logic control circuit, through the Altera Corporation EPM7064 Design and Implementation of CPLD Controller, the expansion of online programming interface to control functions. Function of the circuit including the D / A circuits, I / O circuit, PWM circuit and counter circuit components; system selected analog Devices D / A control device AD7847 or AD5547 as a key device to achieve a 5 ~ +5 V and 0 ~ 10 V analog voltage output.

1.1 based on the IP-core fixed-frequency PWM circuit design

In CO2 laser marking devices, the control circuit card through the PWM output pulse width adjustable frequency control signal on the laser power to control the discharge time to achieve the laser output power of the precise control. Design using CPLD, the design configuration is very flexible and can be designed in accordance with the corresponding function of the overall needs of the IP soft-core, resource-saving board. Al-tera program using the company's hardware AHDL programming language design; EPM7064SLC44-10 combined with the realization of devices PWM controller. IP core based on PWM control circuit, control the clock from the PCI bus 33 MHz clock, interface to the effective use of resources.

IP soft-core 4 kHz output frequency of 33 MHz clock frequency was 8 196. 8 of the control accuracy can be achieved duty cycle 0 ~ 1 256 adjustment, the soft-core prototype of symbols as shown in Figure 2. One, Load control data as a loading control side, in which the signal effectively, it will be 8-bit control data IN [7. . O] loading internal control registers. EN signal to output signal, is used to control PWM output, when the effective signal, the output PWM. LCLKIN signal to provide IP soft core operating frequency, PWM output signal is the baseband frequency by the signal obtained.

PCI-based control of the laser marking system

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Soft-core internal control statement as follows, in which PWM wave output for PWMDATA of control logic, when the output is high, the output flip.

PCI-based control of the laser marking system

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END IF;

END IF;

Soft-core and oscilloscope waveform of the simulation output waveform shown in figure 3.

PCI-based control of the laser marking system

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1.2 based on the IP core adjustable PWM frequency circuit design

The frequency of the PWM pulse width adjustable in the prototype circuit symbols shown in Figure 4. Which, EN signals enable the device; WR write signal and PFD0, PFDl and PCD0, PCDl with the realization of frequency and pulse width control of the written word, for the 12-bit wide control to achieve 4,096 steps. LclkIn for the global clock signal, the signal frequency from 8 hours after the 33 MHz clock of the PCI interface, the IP of nuclear energy to achieve 1 kHz ~ 4 MHz frequency adjustment and 0 ~ 100% of the largest duty cycle 4 096-level regulation. 8-bit data width DATAIn access control data for the El input. IP core functions are as follows:

PCI-based control of the laser marking system

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PCI-based control of the laser marking system

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Functional simulation waveforms shown in Figure 5.

PCI-based control of the laser marking system

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IP core to achieve the use of adjustable frequency PWM circuit logic device on the consumption of internal resources and large, compared to the IP occupied by a fixed frequency of the logic of fewer resources and therefore are more suitable for a fixed frequency laser applications pulse width modulation to provide high accuracy.

2 Control Software

For board debug and the actual laser marking systems, respectively TestStar developed test software and hardware board LaserStar software system for laser marking.

Board functional test software to complete all of the features of the test board.

Options provide access not only for the D / A control output of the test; and to provide DI input signal detection, DO output signal testing; and COUNTER calculator function testing. Pass the test software design, system design to improve the efficiency of the various modules can be separated from the actual performance test designed to detect the inadequacy of the various modules to the system during the process of marking more stable.

Laser marking software system can be easily edit single line body text, TTF text, date, time, serial number; graphics can be automatically aligned, circular typesetting; graphics can be drawn with the mouse; PLT can easily import graphics files, as well as graphics from the BMP image contour extraction. It does not affect the normal operation of production lines, the products can be achieved on the assembly line of laser marking, thereby greatly increasing productivity. Marking speed range of up to O ~ 60 m / min or 1 ~ 20 S / s.

PCI-based control of the laser marking system

System can easily modify the contents of marking, setting the size of marking power, control parameters such as speed. Lines marking smooth, comfortable shade. Users can also design unique security code, because the use of data encryption technology, even if different users have the marking system, marking can not be exactly the same content, making the system with good security features marking. Marking system marking the actual results as shown in Figure 6.

3 Summary and Outlook

The design of computer-based PCI bus control system for laser marking, to improve the control command to send speed and control accuracy. Designed and developed under the Win-dows 2000/xP the WDM driver; to improve the stability of the system; reduction of hardware compatibility and system misoperation caused by crash, blue screen and so on. CPLD devices will be used to deal with local logic and control functions such as data storage rolled into one; the use of Altera's AHDL hardware programming language designed IP soft-core; EPM7064SLC44-10 combined with devices to achieve a fixed frequency and variable frequency output of the PWM signal precision to reduce the use of a separation device, making the system much more modular, simplifying the PCB placement and routing, at the same time conducive to the upgrading and expansion of the system. The use of encryption CPLD excellent performance, will feature information and the encryption system memory in which logic and control software with hardware to achieve encryption, to ensure the uniqueness of the system, which can effectively improve the content of the security marking ability. The control system has been widely used in industrial fields.


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