Numerical control device, and screen display and data input and output method for numerical control device

A personal computer incorporated in a numerical control device (CNC) has a function for emulating a CNC display circuit. This personal computer emulates a CNC display circuit and converts a transmitted display command A into a video signal for transmission to display means. The numerical control device (CNC) incorporating this personal computer need not to provide a display circuit for each of the CNC body and the personal computer, and, moreover, a switching circuit for selectively receiving the video signals from two display circuits and transmitting selected signal to the display means is not required either. Furthermore, the personal computer has a function for emulating a data input/output circuit of CNC. The personal computer inputs or outputs data transmitted from the CNC or data to be transmitted to the CNC, from or to a data input/output circuit in the personal computer to or from an external input/output device, through an input/output data RAM. Therefore, it is not necessary to provide data input/output circuits for both the CNC body and the personal computer.

FIELD OF THE INVENTION
 The present invention relates to a numerical control device, and more
 particularly, to a screen display and data input/output method for a
 numerical control device.
 DESCRIPTION OF THE RELATED ART
 Generally, a numerical control device comprises a control section and a
 drive section, and the control section can be divided further into a
 section for controlling data input operations, and a section for
 generating machine control information in real time on the basis of input
 information and transferring commands to the drive section.
 Usually, the control section is provided with a dedicated computer and
 software for control purposes, and the drive section comprises a servo
 motor or main axis motor, or a servo amplifier for driving a motor of this
 kind. In order to carry out machining using a machine tool controlled by a
 numerical control device, in general, a processing program is previously
 created or input by the input operation control section in the control
 section of the numerical control device, and processing commands are
 output to the drive section in accordance with this processing program,
 thereby controlling the driving mechanism of the machine tool.
 The aforementioned numerical control device is also provided with a display
 device, which displays various information, such as the input data,
 control status, etc., and is used in input operations and control.
 FIG. 4 is a block circuit diagram for describing an outline of the display
 function of a conventional numerical control device. In FIG. 4, parts of
 the composition other than the display function of the numerical control
 device are omitted. In the diagram, a body (hereinafter, referred to as
 CNC body,) 1, comprising a control section and a drive section of a
 numerical control device, is connected via a bus 3 to a display circuit
 (hereinafter, referred to as CNC display circuit) 5, which drives a
 display device 4. The CNC body 1 is also connected via the bus 3 to input
 means 1a, such as a keyboard and a pointing device, such as a mouse and
 the like, and input data A is stored in a data RAM 1c.
 In performing the display operation in the numerical control device, bit
 map data or graphics commands (B1) generated on the basis of the data
 stored in the aforementioned RAM 1c or the data in the CNC body 1 is
 transferred via the bus 3 to CNC display circuit 5, which generates a
 video signal B2 by means of analytical software stored in an internal RAM
 5b, and provides required display on the display device 4.
 Reference numeral 21 denotes a data input/output circuit comprising an
 interface conforming to standards such as RS232C, PCMCIA, or the like, and
 is designed for data input/output between the body 1 and an external CNC
 input/output device 22 for CNC.
 By connecting a numerical control device of this kind to a personal
 computer which can easily be extended and adapted, the functions of an
 existing numerical control device can be modified or extended in
 accordance with the operator's needs or convenience.
 FIG. 5 is a block diagram for describing an outline of a display function
 of a numerical control device incorporating a personal computer. In the
 composition shown in FIG. 5, a personal computer 2 is connected via a bus
 3 to the numerical control device having the composition illustrated in
 FIG. 4 above, and both the CNC display circuit 5 and a display circuit 2a
 of the personal computer 2 are designed to be connectable to a common
 display device 4 by means of a switching circuit 6. When the CNC body 1 is
 to provide a display, it does so by transmitting a video signal B2 to the
 display device 4 by means of the CNC display circuit 5. On the other hand,
 when the personal computer 2 is to provide a display, it does so by
 transmitting a video signal C to the display device 4 by means of a
 display circuit 2a. In this method, a switching circuit 6 is provided
 among the CNC display circuit 5, personal computer 2 and the display
 device 4 in order that data from both the CNC body and the personal
 computer can selectively be displayed using the common display device 4 by
 operating the switching circuit 6 for selecting either video signal B2 or
 Video signal C, thereby transmitting one of the video signals to the
 display device 4. The memory means 2b is for storing software for
 controlling the personal computer, and data input/output between the
 personal computer and an external input/output device 24 for the personal
 computer is made by means of a data input/output circuit 23 conforming to
 standards such as RS232C, PCMCIA or the like.
 Therefore, with a conventional numerical control device incorporating a
 personal computer, it is not only necessary to provide a display circuit
 for both the CNC body and the personal computer but also necessary to
 provide a switching circuit for selecting the video signal by its source,
 that is, the two display circuits, to transfer the selected signal to the
 display device. Furthermore, in the case of the conventional numerical
 control device, for data input/output, a separate data input/output
 interface for the personal computer (data input/output circuit 23), and a
 separate CNC data input/output interface (data input/output circuit 21)
 are required.
 SUMMARY OF THE INVENTION
 In a numerical control device incorporating a personal computer, and a
 screen display and data input/output method for a numerical control
 device, it is an object of the present invention to conduct screen display
 and data input/output without using a CNC display circuit and a switching
 circuit.
 In order to achieve the aforementioned object, the screen display and data
 input/output method according to the present invention comprise steps of:
 transferring display commands generated by a numerical control device to a
 personal computer incorporated in the numerical control device, emulating
 a display circuit function of the numerical control device to convert the
 display commands into a video signal and transmitting the converted video
 signal to display means, and displaying display contents from the
 numerical control device on a screen of the display means using the video
 signal. Further, it is preferable for the present invention to have an
 external input/output device connected to the computer, and comprise the
 steps of: transferring data from the numerical control device to the
 personal computer and, through which, outputting the data to the external
 input/output device, when the display contents from the numerical control
 device is displayed on a screen of the display means, and transferring
 numerical control data input from the external input/output device to the
 numerical control device.
 Furthermore, in the numerical control device according to the present
 invention, a personal computer is connected via a bus to a numerical
 control device body, and a converting means for emulating a function for
 displaying display commands generated by the numerical control device body
 is added to the circuitry of the personal computer so that display command
 generated by the numerical control device body can be converted into a
 video signal by the converting means and displayed.
 Preferably, the converting means comprises data storing means for storing
 display command, and conversion control means for converting display
 command into a video signal and controlling output thereof.
 More preferably, the conversion control means comprises software storing
 means, the software storing means being designed for storing analytical
 software for analyzing and converting display command into a video signal,
 and drivers for controlling output of the video signal.
 Even more preferably, the personal computer comprises data transfer means
 for transferring data between the personal computer and the numerical
 control device, and data input/output means for data input/output between
 the personal computer and the external input/output device.
 According to the present invention, in a numerical control device
 incorporating a personal computer, it is possible to display on a screen
 the contents of display command generated by the numerical control device
 body, without providing a display circuit or switching circuit for the
 numerical control device body.
 Furthermore, since it is not necessary to provide a data input/output
 circuit or interface for the numerical control device body in order to be
 connected to an external input/output device, the composition of the
 numerical control device can be simplified and thus manufacturing costs
 can be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Firstly, a description is given of a servo motor control system in a
 numerical control device, to which an embodiment of the present invention
 can be applied, with reference to the schematic block diagram in FIG. 2.
 The servo motor control system used here is virtually the same as a
 conventional control system, and is therefore only described in general
 terms here.
 In FIG. 2, 10 is a CNC control section including a computer; 11 is a common
 RAM; 12 is a digital servo circuit including a processor (CPU), ROM and
 RAM and the like; 13 is a power amplifier, such as a transistor inverter
 or the like; 14 is an AC servo motor; 15 is an encoder for generating
 pulses as the AC servo motor 14 rotates; and 16 is a rotor position
 detecting device for detecting the rotor phase.
 The CNC control section 10 and common RAM 11 form the control section CTR
 of the numerical control device; and the common RAM 11, digital servo
 circuit 12, power amplifier 13, AC servo motor 14, encoder 15, and rotor
 position detecting device 16 form the drive section DRV of the numerical
 control device. Usually, the control section CTR is provided with a
 dedicated computer and software for control purposes, and the drive
 section DRV is provided with a servo motor or main axle motor, or a servo
 amplifier for driving such a motor. Generally, in carrying out machining
 by means of a machine tool controlled by the numerical control device, a
 machining program is previously created or input by the input operation
 control section of the control section CTR, and machining commands are
 output to the drive section DRV in accordance with this machining program,
 thereby controlling the driving mechanism of the machine tool.
 A generally used CNC control section comprises a section for controlling
 data input operations (CNC display circuit), and a section for generating
 machine control information in real time on the basis of input information
 and transferring commands to the drive section, but the CNC control
 section 10 in the numerical control device incorporating a personal
 computer according to the present invention does not comprise a CNC
 display circuit, by performing the function of the CNC display circuit by
 emulation on the side of the personal computer.
 Next, a mode for implementing a numerical control device incorporating a
 personal computer according to the present invention is described using
 the schematic block diagram in FIG. 1.
 In FIG. 1, the numerical control device incorporating a personal computer
 can be formed by a configuration wherein a CNC body 1 (numerical control
 device body) is connected to a personal computer 2 via a bus 3.
 The CNC body 1 comprises a control section CTR including at the least a CNC
 control section 10 and a common memory 11, as illustrated in FIG. 2, and
 the drive section CTR comprises storing means 1b for storing software for
 controlling the CNC body, and storing means 1c for storing generated data.
 Here, the storing means 1b and 1c may be constituted either of the common
 RAM 11 or of a dedicated RAM.
 The personal computer 2 may comprise a signal conversion means 20a added to
 a generally used personal computer. A personal computer 2 includes in its
 standard sections storing means for storing software for controlling the
 personal computer, and a display circuit 2a. And the display contents from
 the personal computer 2 itself are generated by the display circuit 2a,
 which is a standard section, in the form of a video signal C, and are then
 displayed by transmitting this video signal C to the display device 4.
 A personal computer incorporated into the numerical control device
 according to the present invention is provided with signal converting
 means 20a for emulating the display function of the CNC body 1. This
 signal converting means 20a comprises data storing means 20c for receiving
 and storing display contents from the CNC body 1, software storing means
 20b for storing analytical software for analyzing data stored in the data
 storing means 20c and generating a video signal, and a driver (software)
 for controlling the output of the video signal and transmitting it to the
 display device 4. The driver software can be formed using command
 designated by the user through the personal computer.
 The display contents deriving from the CNC body 1 comprise, for example,
 bit map data, graphics command or the like, and the analytical software
 analyzes the bit map data and the digital data for the graphics commands
 to generate analogue video signal B2. The personal computer 2 generates a
 video signal B2 corresponding to the display contents from the CNC body 1
 using this analytical software, and it controls the output of the
 generated video signal B2 using the driver.
 Therefore, the personal computer 2 transfers the display contents from the
 personal computer to the display device 4 by means of the display circuit
 2a in the form of a video signal C, and a screen showing these display
 contents is displayed, and, furthermore, it transfers the display contents
 from the CNC body to display device 4 by means of the appended signal
 converting means 20a in the form of a video signal B2, and a screen
 showing these display contents is displayed.
 The selection regarding which of video signal B2 or video signal C is
 output can be made by switching in the personal computer. Possible methods
 for switching video signal include a method of switching based on key
 input, or the like, at the personal computer, or a method whereby the
 personal computer monitors the data storing means 20c periodically and
 generates a video signal when it detects that display contents from the
 CNC body are stored in the data storing means 20c, the display being
 switched from the personal computer display to the CNC body display in
 accordance with a display request, or the like.
 A RAM, or the like, for example, may be used as aforesaid storing means.
 Therefore, according to the mode for implementing the present invention
 illustrated in FIG. 1, it is possible to omit the CNC display circuit and
 the video signal switching circuit. Furthermore, even if the device
 composition omits the CNC display circuit, emulation can be made by means
 of analytical software in the personal computer, and the display contents
 are analyzed and converted into a video signal, so that similar operation
 to that performed by a CNC display circuit can be achieved.
 Moreover, since the operator can determine commands for the driver as he or
 she wishes, the operation can be modified to suit the operator's method of
 application, without changing the CNC body.
 Next, a further mode for implementing a numerical control device
 incorporating a personal computer according to the present invention is
 described with reference to the schematic block diagram in FIG. 3.
 The composition of the personal computer 2 required for omitting the CNC
 display circuit and video signal switching circuit, in other words, the
 composition of the signal converting means 20a, data storing means 20c,
 and software storing means 20b, is similar to that in the mode of
 implementation illustrated in FIG. 1.
 The data RAM 1d in the CNC body 1 functions as a data input/output buffer
 between the CNC body 1 and an external input/output device.
 The data RAM 25c in the personal computer 2 is a data input/output buffer
 between the personal computer 2 and an external input/output device, and
 it is connected to the microprocessor of the personal computer via an
 internal bus. The data input/output circuit 23 comprises an interface
 conforming to RS232C standards, PCMCIA standards, or the like, connected
 to the external input/output device 26, and it is connected to the
 internal bus of the personal computer 2.
 Similarly to a conventional personal computer, the analytical software 25b
 has a function for successively reading data of a prescribed length from
 the data input/output circuit 23 by means of the microprocessor in the
 personal computer 2 and storing the data temporarily in the data RAM 25c,
 when the data for personal computer is displayed on the screen of the
 display device 4, and storing the contents of this data in a main memory
 of the personal computer 2 via the microprocessor of the personal computer
 2 (when data from the external input/output device 26 is to be input to
 the personal computer 2), as well as a function for successively reading
 data of a prescribed length from the main memory of the personal computer
 2 by means of the microprocessor in the personal computer 2 and storing
 the data temporarily in the data RAM 25c each time reading is carried out,
 and outputting the contents of the data to the data input/output circuit
 23 by means of the microprocessor in the personal computer 2 (when data
 from the personal computer 2 is output to the external input/output device
 24). Hereinafter, these functions are referred to as standard input/output
 functions.
 Furthermore, the analytical software 25b in this mode of implementation has
 a function of successively reading data of a prescribed length from the
 data input/output circuit 23 by means of the microprocessor in the
 personal computer 2 and storing the data temporarily, when the data for
 the numerical control device is displayed on the screen of the display
 device 4, and transferring the contents of this data, each time reading is
 carried out, to the data RAM 1d of the CNC body 1 through the bus and the
 microprocessor in the personal computer 2 (when data from the external
 input/output device 26 is input to the CNC body 1 via the personal
 computer 2) as well as a function for reading data from the data RAM 1d of
 the CNC body 1 by means of the microprocessor in the personal computer 2
 and storing the data temporarily in the data RAM 25c, and outputting the
 contents thereof to the data input/output circuit 23 via the
 microprocessor in the personal computer 2 (when data from the CNC body 1
 is output to the external input/output device 26 via the personal computer
 2). Hereinafter, these functions are referred to as remote input/output
 functions.
 In brief, the analytical software 25b comprises a driver software providing
 standard input/output function and a driver software providing remote
 input/output function. When data for the numerical control device is
 displayed on the screen of the display device 4 by the input means 1a, the
 driver software providing remote input/output function is selected to
 enable the data for the numerical control device to be input and output.
 Furthermore, when data for the personal computer is displayed on the
 screen of the display device 4, the driver software providing the standard
 input/output functions is selected and data for the personal computer can
 be input and output.
 Consequently, the CNC body 1 and external input/output device 26 can be
 connected indirectly through the personal computer 2, and so, even when a
 data input/output circuit 21, as illustrated in the conventional example
 in FIG. 5, and an RS232C- or PCMCIA-standard interface, or the like is not
 provided additionally in the CNC body 1, data can be input and output
 between the CNC body 1 and the external input/output device 26. Hence, by
 composing a CNC body 1 without comprising an input/output circuit 21 or an
 RS232- or PCMCIA-standard interface or the like, the composition of the
 CNC body 1 can be simplified, and, as a result, its manufacturing costs
 can be reduced.