CN2148323Y - Testing apparatus for grating digital display instrument - Google Patents

Abstract

The utility model relates to a testing apparatus for a raster digital display instrument which is composed of an outer shell, a panel comprise a plurality of control keys and buttons and a display device and an electronic circuit. The electronic circuit adopts a microprocessor of 16 bits. A procedure which is used to test the precision and the frequency response of the raster digital display instrument is solidified in the EPROM and a seven core output socket and a nine core output socket are used to be connected with the socket for the signal input of the raster digital display instrument. The electronic circuit also comprises a D/A circuit, an interface circuit, a decoding circuit, etc. Different parameters of can be arranged by regulating the control keys and buttons on the panel to adapt to the test of raster digital display instruments with different specifications and different precision. The utility model has the advantages of intellectualization, high precision, convenient operation and reliability.

Description

Testing apparatus for grating digital display instrument

The utility model relates to a kind of intelligentized electronic instrument, is specially adapted to the precision and the frequency response test of grating digital readout.

Along with constantly delivering of China's machinery and electronics industry, digital display and numerical control device have obtained applying rapidly at China's machine industry, have greatly improved the technical merit of China's lathe production and machining.At present, the grating digital readout that China produces has possessed the technical merit of the international middle and later periods eighties, and has formed certain batch.Yet, China's digital display industry all is provided with regular, effective digital display meter detection means up till now, particularly precision, frequency response, accuracy detect, these performances are the indexs that influence digital display meter quality most critical, this has not only influenced the production in enormous quantities and the outlet of high precision digital display meter, also often brings sensor production producer and the digital display meter manufacturer contradiction on sensor accuracy and digital display meter precision problem.

The purpose of this utility model will be developed a kind of microprocessor that adopts, and can adapt to the precision of grating digital readout of plurality of specifications and the grating digital readout tester of frequency response test.

The grating digital readout tester that the utility model proposes, by shell, the panel (as shown in Figure 1) that comprises a plurality of control key buttons and display device, several parts of cased electronic circuit constitute, the part of forming electronic circuit includes, the microprocessor of 16 bit, crystal oscillator and clock generator, buffer circuit, RAM, decoding scheme, timer conter and interruptable controller (as shown in Figure 2), electronic circuit also includes: the EPROM that is used for test gratings digital display meter precision and frequency response program is housed, be used for seven cores or nine core output sockets and the D/A circuit that are connected with the digital display meter signal input socket, the display keyboard interface circuit that is connected with a plurality of control key buttons on the panel and display device.The input end of EPROM, display keyboard interface and D/A circuit is connected with the data/control bus of the microprocessor of 16 bit through buffer circuit, and the output terminal of D/A circuit is connected with seven cores or nine core output interfaces through operational amplifier.The D/A circuit is made of two integrated circuit ADC7524, (as shown in Figures 3 and 4), the 4-11 pin of ADC7524 is connected with the data bus of the microprocessor of 16 bit, 12 pin are connected with 15 pin of decoding scheme LS138,1 pin is connected with the inverting input of operational amplifier, 2 pin, 3 pin are connected with in-phase input end, 16 pin through a potentiometer be connected with seven cores and nine core output sockets through a triode again after the output terminal of operational amplifier is connected.The display keyboard interface circuit by integrated circuit 8255, LS273, LS147, LS148,7447 and 2585A constitute (as shown in Figure 5), 8255 27-34 pin is connected with the data bus of the microprocessor of 16 bit, the PA0-7 port is connected with decoding output terminal as LS147, the LS148 of code translator, the input end of LS273 is connected with the data bus of the microprocessor of 16 bit, and output terminal is connected to 8 charactrons as display device through 2585A.7447 6,2,1,7 pin are connected with 8255 PC0-3 port.The control key button comprises button and rotary switch K1-K11, the decoding input end of LS147 in 10 switch contacts of frequency switching K1 and the display keyboard interface circuit is connected, 8 switch contacts of amplitude K switch 2 are connected with 8 decoding input ends of LS148, Waveform switch K3, break key K4, magnitude of voltage selector switch K5, phase value selector switch K6, divider ratio selector switch K7, working mode selection K switch 8, initiating key K9, crawl key K10, the switch contact that suspends strong K11 are connected with 8255 PBO-7, PC4-7 port respectively.16 figure place processor adopting 8086, two 2764 of EPROM employings, RAM adopt two 6264 and two 6116, and interruptable controller is made of 8254 and 8,259 two integrated circuit.

This tester in use, should be earlier the signal input socket of output interface and grating digital readout be interconnected, in the time will testing the square wave digital display meter, seven core output interfaces of use test instrument, in the time will testing the sinusoidal undulation number scale, nine core output interfaces of use test instrument, after connecting, just tester can be switched on, button switch on the panel is set then, according to the required waveform of grating digital readout and other parameter, set following switch, manual mode (K8), square wave/sinusoidal wave switch (K3), frequency switching (K1), amplitude switch (K2), voltage switch (K5), phaseswitch (K6), divider ratio switch (promptly segmenting number K switch 7), the work of tester is carried out under software control, program leaves among two EPROM2764, after system's energising, enter master routine, scan control key at first, if initiating key K9 is pressed, then enter the computing function module, the computing function mould calculates the digital quantity of output signal according to current each switch value by the control key button setting on the panel, and the result left among two 6264RAM, after calculating is finished, enter the output function module, at this moment, result of calculation is sent number to two D/A under system's control, in the output function module, processor is the run-down supervisory keyboard at regular intervals, change that functional module over to decision, if break key is pressed, then 8 charactrons show current several numerical value that given, and suspend and send number, discharge break key, then count again, if initiating key is connect down, it is initial then to enter master routine, reset state, if reset key is pressed then system reset, under manual mode, press the crawl key, export a segmentation point, do not put then along supervention segmentation point if press the crawl key.

From top narration as can be seen: as long as the control key button on this tester of adjusting panel, this tester just can be used for different size (for example square wave or sinusoidal undulation number show) different accuracy (example 20,40, the measurement of grating digital readout 80 segmentations), tester display digit and digital display meter display digit are compared, just can judge whether digital display meter work is normal, for example, if the tester Set For Current is 40 segmentations, and tested digital display meter is 20 segmentations, the explanation digital display meter was normal when then the tester count value was 2 times of digital display meter count value, otherwise, for undesired, this tester is owing to adopted microprocessor technology, thus reliable operation, stable performance, counting accurately is widely used in the measurement of the various grating digital readouts of present domestic production.

As a specific embodiment of the present utility model, Fig. 2 is the panel figure of tester, the frequency rotary switch provides the selection of 10 class, sinusoidal wave 1KC, 2KC, 3KC ... 10KC, square wave 5KC, 6KC, 7KC, 8KC, 9KC, 10KC, 20KC, 30KC, 40KC, 50KC, the amplitude rotary switch provides the selection of 8 class, sinusoidal wave (5 volts): 0.5V, 0.8V, 1.1V, 1.4V ... 2.6V, sinusoidal wave (12V): 2V, 2.6V, 3.2V, 3.8V ... 6.2V; The magnitude of voltage rotary switch divides third gear: 5V, 9V, 12V; Phase value is selected the branch third gear :-30 °, 0 °, 30 ° divider ratio selector switch are divided third gear 20,40,80, and Fig. 6 is the backboard figure of tester, Waveform switch K3, and x, y, the signal port and the power switch of three coordinates of z, socket is placed on the backboard.Fig. 3, Fig. 4, Fig. 5 is circuit theory diagrams, after energising enters duty, when sixteen bit microprocessor 8086 the 28th pin M/ID is high level, be memory addressing, 20 address wire A0-A19 of this processor send among three LS373 and cushion, this 20 bit address enters address bus afterwards, through HC139,74LS30,74LS33 and two LS138 decodings, storer is carried out access, two LS245 are used for data buffering, by processor 26 pin and the control of 27 legs, when 8086 the 28th pin M/IO are low level, be the port addressing, only use in 20 address wires of this processor A0-A15 totally 16 be used for the port addressing, address wire A3, A4, A5, A6, A7 is through LS138(2) decoding, produce 8259A, the chip selection signal of 8254A, address wire A1-A7 is through LS138(1) decoding, produce the chip selection signal of two D/A slice, thin piece ADC7524 and the chip selection signal of LS273, keyboard and demonstration partly adopt the 8255A parallel port to do the keyboard input, with the A mouth, B mouth and C are high half mouthful, 10 kinds of on off states of K1 switch input, become 42 ary codes through LS147,8 kinds of on off states of K2 switch input, become 32 ary codes through LS148, adopt the C of 8255A low half mouthful and LS273 as showing control, 8255PC0-PC3 connects 7447 slice, thin pieces, produces digital pipeline section choosing, LS273 latchs the choosing of charactron position, and 2585 is that the position choosing drives.Interrupt system is made up of 8254 and 8,259 two slice, thin pieces, and the timing that can produce various time values under software control is interrupted.Tester adopts the output of two 8 D/A chips as sinusoidal signal and cosine signal, and this output signal is used for every performance index of test gratings digital display meter, and the output valve of these two D/A devices is by software control.The course of work of whole tester under software control, the front has illustrated here and has no longer repeated.

Claims (5)

1, a kind of grating digital readout tester, by shell, the panel that comprises a plurality of control key buttons and display device, several parts of cased electronic circuit constitute, the part of forming electronic circuit includes, the microprocessor of 16 bit, crystal oscillator and clock generator, buffer circuit, RAM, decoding scheme, timer conter and interruptable controller is characterized in that: electronic circuit also includes: the EPROM that is used for test gratings digital display meter precision and frequency response program is housed, be used for seven cores or nine core output sockets and the D/A circuit that are connected with the digital display meter signal input socket, the display keyboard interface circuit that is connected with a plurality of control key buttons on the panel and display device.The input end of EPROM, display keyboard interface and D/A circuit is connected with the data/control bus of the microprocessor of 16 bit through buffer circuit, and the output terminal of D/A circuit is connected with seven cores or nine core output interfaces through operational amplifier.

2, tester according to claim 1, it is characterized in that: the D/A circuit is made of two integrated circuit ADC7524, the 4-11 pin of ADC7524 is connected with the data bus of the microprocessor of 16 bit, 12 pin are connected with 15 pin of decoding scheme LS138,1 pin is connected with the inverting input of operational amplifier, 2 pin, 3 pin are connected with in-phase input end, 16 pin through a potentiometer be connected with seven cores and nine core output sockets through a triode again after the output terminal of operational amplifier is connected.

3, tester according to claim 1, it is characterized in that: the display keyboard interface circuit by integrated circuit 8255, LS273, LS147, LS148,7447 and 2585A constitute, 8255 27-34 pin is connected with the data bus of the microprocessor of 16 bit, the PA0-7 port is connected with decoding output terminal as LS147, the LS148 of code translator, the input end of LS273 is connected with the data bus of the microprocessor of 16 bit, and output terminal is connected to 8 charactrons as display device through 2585A.7447 6,2,1,7 pin are connected with 8255 PC0-3 port.

4, tester according to claim 1, it is characterized in that: the control key button comprises button and rotary switch K1-K11, the decoding input end of LS147 in 10 switch contacts of frequency switching K1 and the display keyboard interface circuit is connected, 8 switch contacts of amplitude K switch 2 are connected with 8 decoding input ends of LS148, Waveform switch K3, break key K4, magnitude of voltage selector switch K5, phase value selector switch K6, divider ratio selector switch K7, working mode selection K switch 8, initiating key K9, crawl key K10, the switch contact that suspends strong K11 respectively with 8255 PBO-7, the PC4-7 port is connected.

5, tester according to claim 1 is characterized in that: 16 figure place processor adopting 8086, two 2764 of EPROM employings, RAM adopt two 6264 and two 6116, and interruptable controller is made of 8254 and 8,259 two integrated circuit.

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