JPS63298403A - Data transmission system for numerical controller - Google Patents

Abstract

PURPOSE:To facilitate the addition of an interface print panel, etc., to detect directly the position of a machine by using a 1st position detector which is incorporated to a servomotor and a 2nd position detector which detects directly the position of a machine moving part. CONSTITUTION:A rotary encoder 23 incorporated to a servomotor 22 is used together with an optical scale 26 which detects directly a machine table 25. The signals of the scale 26 are counted by a counter 32 and the contents of the counter 32 are read out by a microprocessor 12 via a standard bus 1 for control of the position of the table 25. Thus the counter 32 is connected to the microprocessor 12 via the bus 1 with no special interface needed. As a result, the interface print panel of the scale 26, i.e., an option can be easily added with no use of a special connector, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data transmission method for a numerical control device, and in particular to a data transmission system for a numerical control device that allows easy addition of an interface printed board for directly detecting machine position. Regarding transmission methods.

[Conventional technology]

Microprocessor systems such as numerical control devices are also VM
Systems are constructed using standard buses such as the E bus and the MULTI bus.

As a result, the printed circuit boards for each function can be shared through the bus interface, providing great benefits in system expansion, modification, design, manufacturing, maintenance, etc. These standard buses typically have hardware interfaces where signals are contained in a single connector, with no free pins available for other purposes.

[Problem that the invention seeks to solve]

On the other hand, numerical control equipment systems have various options, and it is desirable to be able to easily add these options.For example, a rotary encoder built into a servo motor is used as a position detector, but there are other In some cases, direct feedback is obtained from the machine table to increase the height, and an optical scale or the like is used.

Since this interface such as an optical scale is not necessary for all numerical control device systems, it is desirable to be able to easily add it as an option in terms of cost.

However, if the numerical control system uses a standard bus, as mentioned earlier, it is not possible to add signals such as those from optical scales to the standard bus connector due to empty pins, etc. It is conceivable to separately provide a dedicated bus for these options or prepare a special connector, but this is undesirable in terms of cost and mounting on the printed board.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a data transmission system for a numerical control device that allows easy addition of an interface printed board for directly detecting the machine position.

[Means to solve problem number]

In the present invention, in order to solve the above-mentioned problems, as shown in FIG. a first position detector (23) that directly detects the position of the mechanical movable part (25); and a second position detector (26) that directly detects the position of the mechanical movable part (25); a counter (32) that counts and is connected to the standard bus of the numerical control device, and the microprocessor (12) that performs position control reads said counter (32) periodically via the standard bus (1); Provided is a data transmission system for a numerical control device, characterized in that it is configured to provide position information to a position control circuit (10).

[Effect]

The signal from the second detector is counted by a counter, and the microprocessor reads the contents of this counter via a standard bus to control the position. Therefore, a standard bus is used between the counter and the microprocessor, and a special Does not require an interface.

Therefore, an optional printed board for the interface of the second position detector can be easily added without providing a special connector or the like.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 2 shows a schematic configuration diagram of a numerical control system according to an embodiment of the present invention. In the figure, 1 is a standard bus, and a VME bus, a MULTI bus, or another standard bus is used. Reference numeral 10 denotes a position control printed board, which detects the feedback signal of a row encoder built into the servo motor to control the servo motor, and is always used in the standard system. 30 is a printed board for optical scale interface, which is a printed board for detecting the feedback signal of the optical scale attached to the machine table, and is optionally used for a special numerical control device system.

FIG. 1 shows an overall block diagram of an embodiment of the present invention.
1 is a standard bus, and as mentioned above, VME bus, MUL
A TI bus or other standard bus may be used. Reference numeral 10 denotes a position control printed board, which detects the feedback signal of a row encoder built into the servo motor to control the servo motor, and is always used in the standard system.

Reference numeral 11 denotes a bumper for connecting internal signals of the position control printed board 10 to the standard bus 1. 12
is a microprocessor, and the position control printed board 10
control the entire A memory 13 stores control programs and various data. 14 is a counter that counts feedback pulses from a low-resolution encoder, which will be described later, and 15 is a receiver for this purpose.

16 is a DA converter for converting a digital signal to an analog signal to a servo motor, which will be described later.

21 is a servo amplifier, which controls the servo motor 2 by the output signal of the DA converter 16 of the position control printed board 10.
Drive 2. The servo motor 22 has a built-in rotary encoder 23 that outputs a position feedback signal and sends the feedback signal to the receiver 15. The servo motor 22 controls the movement of the machine table 25 via the ball screw 24. A normal numerical control system controls the machine with this configuration.

26 is an optical scale that is directly coupled to the mechanical moving part and generates a position feedback signal. This optical scale 26 is not installed in all machines, but only in machines that require special precision.

30 is a printed board for optical scale interface, which includes a receiver 31, a counter 32, and a buffer 33. The receiver 31 receives the signal from the optical scale 26, converts it into a waveform shape and logic signal level, and outputs the signal to the counter 32.
send to Counter 32 counts this pulse signal. The buffer 33 is for connecting the counter 32 to the standard bus 1, and its interface is configured to match the standard bus 1.

Here, the microprocessor 12 reads the contents of the counter 32 via the standard bus 1 at regular intervals, corrects the feedback signal from the rotary encoder 23 with the feedback signal from the optical scale 26, and performs accurate positioning control. ,Also,
The contents of the counter 32 may be read out by another microprocessor connected to the standard bus 1 and then transferred to the microprocessor 12.

In this way, we installed a counter on the printed board for the optical scale interface to count the feedback pulse of the optical scale, and read it from the standard bus. Optical scale functionality can be easily added as an option without requiring a special interface.

In the above embodiment, the optical scale function was explained as an option, but other options such as an electromagnetic scale can be similarly configured.

〔Effect of the invention〕

As explained above, the present invention is configured so that an optional printed board such as an optical scale interface printed board can be connected to the standard bus, so a special interface for adding options such as an optical scale printed board is provided. Optional functions can be easily added without any need.

[Brief explanation of drawings]

FIG. 1 is an overall block diagram of an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of an embodiment of the present invention.

Claims (1)

[Claims] (1) In a data transmission system for a numerical control device that allows a microprocessor to perform position control, a first position detector built into a servo motor and a second position detector that directly detects the position of a mechanical movable part are used. , a counter that counts output pulses from the second position detector and is connected to a standard bus of the numerical control device; and the microprocessor that performs position control periodically controls the counter via the standard bus. A data transmission system for a numerical control device, characterized in that it is configured to read and provide position information to a position control circuit.