JPH039401A - Numerical controller - Google Patents

Abstract

PURPOSE:To output a logical signal corresponding to the state of an individual external I/O source independently of the common states of external I/O sources by controlling the polarity of external signals at the time of serial transfer in accordance with respective common states of receiver circuits and driver circuits. CONSTITUTION:The I/O part 1 is connected to external machines through plural receiver circuits 2, 3 and plural driver circuits 4, 5. Signals inputted from the external machines to the receivers 2, 3 are simultaneously outputted to a parallel /serial converter 6 as parallel signals and the converter 6 converts the parallel signals from the circuits 2, 3 into serial signals and successively outputs the serial signals to a serial interface 7. Signal transfer between the I/O part 1 and a numerical control part 12 is serially executed through the serial interface 7 and the polarity of the serial signals is controlled in accordance with the common states. Consequently, a logical signal corresponding to the state of the I/O source in each external machine can be outputted independently of the common state or polarity state of the external I/O signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a numerical control device for controlling machine tools and the like, and particularly to a numerical control device that serially transfers external input/output signals from relays, switches, etc.

[Conventional technology]

An interface that connects a numerical control device and an external machine (machine tool or robot, etc.) generally has external input/output (
Due to the increase in the number of signal points of DI/DO), serial interfaces are being used. In particular, external input CDI
) receiver circuits are available in two types: +24V common and OV common, and either common can be selected depending on the external machine. Therefore, when reading the state of a signal source (for example, a contact) of an external machine, the relationship between the logic "1" and "rO" is reversed depending on the common state.

Therefore, in conventional numerical control devices, the common selection signal itself is also input as an external human input (DI) signal, and the state of the external signal source is determined on the numerical control device side.

[Problem to be solved by the invention]

However, in the case of the conventional technology, when switching the common,
Inside the numerical control device, first check the common status signal. Thereafter, the logic of the external input signals is unified by reading the external input signal (DI) and inverting or not inverting the external input signal (DI) depending on the common state signal. This was done similarly for external output (DO) signals. Therefore, as the number of external input/output signal sources increases, the load on the numerical control device increases, the processing of the numerical control device becomes complicated, and logic errors are more likely to occur.

The present invention has been made in view of these points, and provides a numerical value equipped with an input/output circuit that can output a logic signal according to the state of an external input/output source regardless of the state of the external input/output common. The purpose is to provide a control device.

[Means to solve the problem]

In order to solve the above problems, the present invention includes an input/output section that controls the input/output of external signals via a plurality of receiver circuits and driver circuits connected to external machines, etc., and a numerical control section that performs axis control etc. In the numerical control device for serially transmitting the external signal between A numerical control device with features is provided.

[Effect]

Since the signal transfer between the input/output section and the numerical control section is carried out by serial transfer via the serial interface, the polarity of the serial signal should be controlled according to the common state, that is, the polarity should be inverted or non-inverted. For example, the state of a signal source of an externally connected machine has a fixed relationship regardless of its common state. Therefore, the numerical control section can determine the state of the signal source on the machine side regardless of the common state.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram of the hardware configuration of a numerical control device for implementing the present invention. In the figure, input/output (DI
/DO) unit 1 is connected to an external machine (not shown) via a plurality of receiver circuits 2 and 3 and driver circuits 4 and 5. Although two receiver circuits and two driver circuits are shown in this figure, it goes without saying that more than two receiver circuits and driver circuits may be connected.

The receiver circuits 2 and 3 have eight human input signal lines, and an external machine is connected to each input signal line. External machine signals input to the receiver circuits 2 and 3 are simultaneously output to a parallel/serial (P/S) converter 6 as parallel signals.

The parallel-to-serial converter 6 converts the parallel signals of the receiver circuits 2 and 3 into serial signals and sequentially outputs them to the serial interface 7.

It also converts the serial signal from the serial interface 7 into a parallel signal and outputs it to the driver circuits 4 and 5 simultaneously.

The driver circuits 4 and 5 have eight output signal lines, and an external machine is connected to each output signal line. Driver circuits 4 and 5 output parallel signals from parallel-to-serial converter 6 to external machines as control signals.

The serial interface 7 is connected to the serial interface 13 of the numerical control section I2 via an inverting circuit 8, and performs transmission and reception of serial signals. Therefore, the outputs of serial interfaces 7 and 13 are outputted via inverting circuit 8, respectively. The inversion circuit 8 is an inversion control circuit 9
The serial signal may or may not be inverted depending on the control signal. That is, serial interface 7
The serial signals output from and 13 are either inverted and output, or directly output without being inverted.

The common selection circuit 10 and the polarity selection circuit 11 store the common state or polarity state of the receiver circuits 2 and 3 and the driver circuits 4 and 5 as a table, and select the common state or polarity state of the receiver circuits 2 and 3 controlled by the parallel-to-serial converter 6. 3 or the polarity states of the driver circuits 4 and 5 are output to the inversion control circuit 9. At this time, the common state and polarity state tables may be provided for each receiver circuit or driver circuit, or may be provided for each input/output signal line of the receiver circuit and driver circuit.

The inversion control circuit 9 controls the operation of the inversion circuit 8 according to the outputs of the common selection circuit 10 and the polarity selection circuit 11.

Numerical control unit 12 is coupled to input/output (DI/Do) unit 1 via serial interface 13 . The axis control section 14 of the numerical control section 12 inputs and outputs serial signals via the serial interface 13 to execute axis control and the like.

The axis control section 14 has a PC section that executes an axis control function and a sequence control function.

Although this PC section is not shown, the CPU that controls the entire
, a ROM that stores a management program that controls the PMC, a ladder program that controls the machine, and a RAM that stores input/output signals and various data. Side manpower (DI) and output (DO)
Give and receive.

Next, the operation of this embodiment will be explained.

Receiver circuit 2 is OV common, receiver circuit 3 is +24
The case where it is set to V common will be explained. When the contact on the machine side connected to the human power signal line of the receiver circuit 2 is open (off), the receiver circuit 2 outputs a high level "1".
" is output, and when it is closed (on), a low level "0" is output.

In the case of the receiver circuit 3, on the contrary, when the contact on the machine side is open (off), a low level "0" is output from the receiver circuit 3, and when it is closed (on), a high level "1" is output.
' will be output.

On the other hand, the axis control unit 14 of the numerical control unit 12 determines that the contact on the machine side is open (off) when the high level is "1", and determines that the contact on the machine side is closed (on) when the low level is "0".

When the parallel-serial converter 6 manually inputs the parallel signal from the receiver 2 and transfers it to the numerical control unit 12, the common selection circuit 10 outputs a low level "0",
It outputs to the inversion control circuit 9 that the receiver 2 is OV common. The inversion control circuit 9 does not operate the inversion circuit 8 due to this low level "0". That is, the inverting circuit 8 does not invert the output of the serial interface 7. Therefore, the serial signal from the parallel-to-serial converter 6 is directly transmitted from the serial interface 7 to the numerical control unit 1.
The signal is output to the serial interface 13 of No. 2.

Next, when the parallel-serial converter 6 manually inputs the parallel signal from the receiver 3 and transfers it to the numerical control unit 12, the common selection circuit 10 outputs a high level r1, and the receiver 3 receives the +24V common signal. A certain fact is output to the inversion control circuit 9.

The inversion control circuit 9 operates the inversion circuit 8 by this high level "1". That is, the inverting circuit 8 inverts the output of the serial interface 7.

Therefore, the serial signal from the parallel-to-serial converter 6 is inverted and output from the serial interface 7 to the serial interface 13 of the numerical control section 12. Therefore, the contact on the machine side connected to the receiver circuit 3 is open (off), and the receiver circuit 3 outputs a low level "
Even if ``0'' is output, the serial interface 13 of the numerical control unit receives the inverted output, that is, a high level ``1'', and the axis control unit 14 inputs the machine-side contact when it is open (off). I can judge something.

By performing the above operations for the driver circuits 4 and 5 as well, the numerical control section 12 can control the contacts on the machine side regardless of the polarity state of the machine that controls the driver circuits.

In the above embodiment, a case was explained in which a common selection circuit or a polarity selection circuit is output for each receiver circuit or driver circuit, but a control signal is sent to an inversion control circuit for each input/output signal line of a receiver circuit or a driver circuit. It may also be possible to output . Furthermore, the inverting circuit 8 may be provided either before or after the serial interface 70.

As described above, according to this embodiment, it is only necessary to invert the polarity of the serial signal according to the common state or the polarity state, and since the inverting circuit only inverts the serial signal, the addition of small-scale hardware for one bit is required. It becomes possible to realize this.

〔Effect of the invention〕

As explained above, according to the present invention, a numerical value equipped with an input/output circuit that can output a logic signal according to the state of the input/output source of an external machine regardless of the common state or polarity state of the external input/output signal. A control device can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the hardware configuration of a numerical control device for implementing the present invention. 2.3 4.5 7, 13 10 ″ 1 2 Input/output (DI/D○) section Receiver circuit Driver circuit Parallel/serial converter Serial interface Inversion circuit Inversion control circuit Common selection circuit Polarity selection circuit Numerical control section 4 axis control part

Claims (4)

[Claims] (1) The external signals are transmitted between an input/output unit that controls the input/output of external signals via multiple receiver circuits and driver circuits connected to external machines, etc., and a numerical control unit that performs axis control, etc. A numerical control device for serial transfer, characterized in that a means is provided for controlling the polarity of the external signal during the serial transfer according to the common state and polarity state of each of the receiver circuit and the driver circuit. Device. (2) The numerical control device according to claim 1, wherein the common state and polarity state are set for each of the receiver circuit and driver circuit. (3) The numerical control device according to claim 1, wherein the common state and polarity state are set for each group of the receiver circuit and the driver circuit. (4) The input/output unit inverts or non-inverts the polarity of the signal depending on the common state and the polarity state. Control device.