JP3613289B2 - Numerical controller for distributed numerical control system and data transmission system using the same - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a data transmission system in which numerical control devices are distributed and arranged for each axis of a machine tool, a robot, or an integrated body thereof, and the numerical control device thereof, and in particular, a data transmission system that realizes synchronous operation of each axis, and It relates to the numerical control device .
[0002]
[Prior art]
FIG. 4 is a diagram showing a configuration of a distributed numerical control system.
In the system shown in FIG. 4, each of the numerical control devices 31 and 32 transmits the movement data to the numerical control devices 31 and 32 that drive and control the plurality of axis servo systems 21 and 22, respectively. Each axis servo system 21, 22 is controlled independently. Each of the numerical control devices 31 and 32 includes a buffer register 31 ₅ and 32 ₅ for temporarily storing data from the axis group manager 10 received via the transmission interfaces 31 ₁ and 32 ₁ , the transmission interfaces 31 ₁ and 32 ₁ , and a CPU. part ₃₁ 2, 32 _2, the speed command unit ₃₁ 3, 32 _3, includes a servo controller ₃₁ 4, 32 _4, the motor 21 rotates by a servo controller ₃₁ 4, 32 ₄ each axis servo system 21, 22 is controlled and a _1, 22 ₁ and the motor ₂₁ 1, 22 ₁ of the rotation amount detecting servo controller ₃₁ 4, 32 position detectors ₂₂ 1 to be sent to _4, 22 _2.
[0003]
The speed command unit ₃₁ 3, 32 ₃ gives a speed command corresponding to the command value sent from the shaft group management unit 10 through the transmission interface ₃₁ 1, 32 ₁ to the servo controller ₃₁ 4, 32 _4, the servo controller 31 ₄ and 32 ₄ , feedback control is performed in which the speeds of the motors 21 ₁ and 22 ₁ are set according to the speed commands in accordance with the detection outputs of the position detectors 22 ₁ and 22 ₂ . In this feedback control, to the servo controller 31 _4, 32 _4, which sends the desired quantity of pulses in a short time, for example, it can be realized by a circuit shown in FIG.
Figure 4 CPU unit ₃₁ shown in 2, 32 ₂ in the CPU (not shown) sets the direction _{(D 7)} and velocity data _(D 0 to D ₅₎ to the data bus, issues a WRSG signal, The data enables the binary rate multiplier 9 written in the D flip-flop 8.
[0004]
After counting 64 pulses of SP, the binary rate multiplier 9 outputs EO, resets the RS flip-flop 10, and disables itself. Directed by D ₇ input data content of pulses during this time, it outputs the + FP or -FP. This number of pulses is the amount of movement. Here, an example in which three numerical control devices are provided and three-axis synchronous operation is performed will be described. First, the transfer format will be described. Generally, when data is transferred from a master station (here, an axis group manager ) to a plurality of slave stations (here, a numerical controller), high-level data link control (hereinafter referred to as HDLC). (Referred to as JIS standard C-6363). The HDLC transfer format is shown in FIG. An address, a command, data, and a cyclic redundancy check are placed between flags indicating the start and end of one cycle. One cycle is called a frame, and this frame is continuously transmitted.
[0005]
In the following description, a frame will be described on the assumption that one cycle of a transfer pattern is composed of one common frame corresponding to all numerical control devices and three unique frames corresponding to individual numerical control devices.
When this state is shown in FIG. 7, F _n−1 , F _n−2 , and F _n−3 are unique frames, and F _n−0 is a common frame.
Next, a specific operation of the above-described distributed numerical control system will be described with reference to FIGS.
FIG. 8 and FIG. 9 are diagrams showing the configuration of the main part relating to the operation of the distributed numerical control system shown in FIG. Group management device 10 is the three numerical control device 31 to 33 (hereinafter, respectively referred to as NC1～NC3) manages _{the, F n-1, F n} -2, F n-3 shown in FIG. 7 Information corresponding to each numerical control device NC1, NC2, NC3 is individually recorded, and information corresponding to all numerical control devices NC1 to NC3 is stored in Fn _-0 .
[0006]
(1) Assume that the address of the frame F _n−1 is “00000001” and the numerical control NC1 is designated. Thus NC1 fetches the command data following the address and receives the frame _{F n-1} in the buffer register 31 _5.
NC2 and NC3 are naturally ignored.
(2) It is assumed that the address of the frame F _n-2 is “00000010” and the numerical controller NC2 is designated. Thus NC2 fetches the command data following the address and receives the frame _{F n-2} to the buffer register 32 _5.
NC1 and NC3 are naturally ignored.
(3) It is assumed that the address of the frame F _n-3 is “00000100” and the numerical controller NC3 is designated. Therefore NC3 fetches the command data following the address and receives the frame _{F n-3} in the buffer register 33 _5.
[0007]
NC1 and NC2 are naturally ignored.
During the above (1) to (3), NC1 to NC3 are operating according to the data fetched in the previous cycle.
(4) It is assumed that the addresses of the frame F _n-0 are “11111111” and all numerical control devices NC1 to NC3 are designated.
Therefore, the frame F _n-0 is received by all the numerical controllers NC1 to NC3, and the NC1 to NC3 commonly take in command data following the address.
During this capture, NC1 to NC3 are still operating with the data captured in the previous cycle.
(5) When the capturing is completed, the contents of the buffer registers 31 ₅ , 32 ₅ , and 33 ₅ are written in the speed commanders 31 ₃ , 32 ₃ , and 33 ₃ , and activated at the same time.
[0008]
However, the calculation speed of each NC is adjusted in advance so that the speed command calculation of the previous cycle is completed until immediately before the capturing is completed. The operation described above enables complete synchronous operation of each axis. Conventionally, complete synchronization could not be performed due to an error in the calculation speed of each NC. However, in this conventional example , since the calculation start time is completely synchronized every transfer cycle, the error is absorbed within one cycle, and the axis It will not affect the operation of. This is because the time required for one cycle of transfer is about several milliseconds as shown in FIG. 10, and the variation of the clock within that time is within several microseconds. This order has no effect on the movement of the servo motor that drives the shaft. Further, even during the resting time until restart, the speed command value is merely rested and is not related to the motor.
[0009]
[Problems to be solved by the invention]
In the conventional data transmission system described above, the axis group manager, which is the primary station, sends a broadcast (common address command) to the plurality of numerical control devices, which are the secondary stations, and each secondary station that receives the broadcast simultaneously. By capturing data, the operation of each axis controlled by each secondary station is synchronized. The response characteristics required for each axis are not all the same. For a specific axis, fast responsiveness may be required, but in the conventional method, a broadcast that is an address of a common address is not sent. Each secondary station does not take in data. For this reason, there is a problem that data cannot be transmitted more than the period for sending a broadcast, and that fast data transmission cannot be performed only to a secondary station that manages a specific axis.
[0010]
The present invention has been made in view of the problems of the prior art as described above, and a data transmission system capable of performing data transmission faster than a period for sending a broadcast for a specific secondary station. It aims to be realized.
[0011]
[Means for Solving the Problems]
The numerical controller of the distributed numerical control system of the present invention is a numerical controller provided in plural for one axis group manager ,
A buffer register for temporarily storing data fetched from each unique frame;
A speed command device that gives a speed command to the servo controller according to the command value sent from the axis group manager,
Receives data for axis movement in a transfer format composed of a common frame that is commonly generated by the axis group manager and that corresponds to the numerical control device, and a unique frame that individually corresponds to each numerical control device. In a numerical controller of a distributed numerical control system that performs drive control of a single mechanical movement axis,
Each numerical controller is
When an activation signal is received, a timer interrupt signal is output after the transmission of the unique frame from the axis group manager to the numerical control device that requires fast data transmission within one data transmission cycle A timer circuit to
Each time a common frame is received, the speed command device is started by the data stored in the buffer register and the start signal is output to the timer circuit, and then the timer interrupt signal from the timer circuit is received. And a CPU section for starting up a speed commander according to data stored in the buffer register.
[0012]
Data transmission system of the present invention is a data transmission system using the numerical controller of the distributed numerical control system configured as described above, the shaft manager in data transmission in the same period, a predetermined numerical control The device is characterized in that the unique frame is transmitted twice or more.
[0013]
[Action]
In the numerical controller of the distributed numerical control system of the present invention, the CPU unit is stored in the buffer register when a common frame is sent from the axis group manager and when a timer interrupt signal is output from the timer circuit. Starts the speed commander according to the data being received. If the axis group manager is configured to send a unique frame more than once for a given numerical control device within the same period, and a timer interrupt signal is output from the timer circuit after the first unique frame is sent, The speed command device is activated only for the numerical control device, and data transmission faster than the normal cycle is performed.
[0014]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention. In the present embodiment, nine secondary stations 40 to 48 are provided for one primary station 100.
FIG. 2 is a block diagram showing in detail the configuration of the primary station 100 and the secondary stations 40 to 48 in FIG. In FIG. 2, the primary station 100 is represented as an axis group manager 110, and the secondary stations 40 to 48 are represented as a numerical controller 131 that controls the axis servo system 121.
The configuration of the axis servo system 121 including the axis group manager 110 and the motors 121 ₁ and 121 ₂ in FIG. 2 is the same as that of the conventional axis group manager 10 and the axis servo system 21 shown in FIG.
[0015]
For the numerical control apparatus 131 in this embodiment, it is provided with a timer circuit 131 ₆ to the conventional numerical controller 31 shown in FIG. The other transmission interfaces 131 ₁ , CPU 131 ₂ , speed commander 131 ₃ , servo controller 131 _4, and buffer register 13 ₅ are configured and operated as transmission interfaces 31 ₁ , provided in the numerical controller 31 shown in FIG. CPU unit 31 _2, the speed command unit 31 _3, described is the same as the servo controller 31 ₄ and the buffer register 31 ₅ will be omitted.
Timer circuit 131 _6, when the simultaneous broadcast occurs, is provided to generate a timer interrupt after the predetermined time has elapsed. When CPU 131 ₂ sent the simultaneous broadcast sends the timer start signal S1 to the timer circuit 131 _6, a timer circuit 131 ₆ accepted the activation signal S1, CPU timer interrupt signal S2 after a predetermined time has elapsed It is returned to the part 131 _2.
[0016]
FIG. 3 is a diagram showing a data transmission state in this embodiment. The operation of this embodiment will be described with reference to FIG.
In the data transmission of the present embodiment, fast data transmission is required for the secondary stations 40 to 47, and particularly fast data transmission is not required for the secondary station 48.
Half-duplex communication is performed between the primary station 100 and the secondary stations 40 to 48 as shown in FIG. In FIG. 3A, the line above shows transmission from the primary station 100, and the line below shows transmission from the secondary stations 40 to 48. For example, when the primary station 100 transmits data to the secondary station 40, a return for the data transmission is performed. The data length and the transmission cycle are constant, and the interval at which the address of the FF that is a broadcast is sent out, that is, one cycle of data transmission is 2 ms.
[0017]
The axis group manager 110, which is the primary station, transmits FF, which is a simultaneous broadcast, and then transmits data to the secondary stations 40 to 47 in succession twice, and then transmits data to the secondary station 48. Do. When the primary station transmits a broadcast, an interrupt as shown in FIG. 3B occurs in each of the secondary stations 40 to 48 whose configuration is shown in FIG. CPU 131 ₂ outputs the start signal S1 to the timer circuit 131 ₆ fetches the data already written into the buffer register 131 ₅ The interrupt. Timer circuit 131 ₆ returns the timer interrupt signal S2 to the 1ms after elapse of 1/2 cycles as shown in FIG. 3 (c) to the CPU 131 _2. CPU 131 ₂ accepting the timer interrupt signal S2 takes the data written in the buffer register 131 ₅ similarly to the interrupt by simultaneous broadcast.
[0018]
In this embodiment, as described above, data transmission from the primary station to the secondary stations 40 to 47 is performed twice in succession, and when the timer interrupt signal S2 is output, the secondary stations 40 to 47 are output. The content of the buffer register provided in 47 is a new rewritten content captured in the previous cycle currently being executed. Therefore, when the timer interrupt signal S2 is taken in, each of the secondary stations 40 to 47 can perform a new operation, and the actual transmission cycle for the secondary stations 40 to 47 is 1 ms. ing. For the secondary station 48 that does not require fast data transmission, a new instruction is not written in the buffer register when the timer interrupt signal S2 is generated. It is 2 ms as well as the case without it.
[0019]
In the present embodiment described above, the delay time of the timer circuit has been described as 1 ms in which the data transmission period to the secondary stations 40 to 47 is ½ cycle, but this delay time is a fast data within one cycle. The timing is not particularly limited as long as the timer interrupt signal is transmitted after the first transmission to the secondary station that requires transmission is completed.
Further, the timer interrupt signal S2 is transmitted every predetermined time, and a plurality of timer interrupt signals S2 are transmitted within one cycle. Further, by adjusting the order of data transmission specific to each secondary station from the primary station, It is possible to further increase the types of data transmission cycles for each station.
Although the simultaneous control of nine axes has been described above, the present invention can naturally be implemented for multi-axis more than that.
[0020]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
Since the data written in the buffer register is fetched a plurality of times, a response faster than the data transmission cycle of the axis control station is possible. By combining the two, it is possible to perform fast data transmission only for a specific secondary station.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention.
FIG. 2 is a block diagram showing in detail the configuration of a primary station 100 and secondary stations 40 to 48 in FIG.
3 is a diagram showing a data transmission state in the embodiment shown in FIGS. 1 and 2. FIG.
FIG. 4 is a diagram showing a configuration of a conventional example of a distributed numerical control system.
FIG. 5 is a diagram showing a configuration example of a speed command device in a conventional example.
FIG. 6 is a diagram illustrating a specific operation of a conventional example.
FIG. 7 is a diagram illustrating a specific operation of a conventional example.
FIG. 8 is a diagram illustrating a specific operation of a conventional example.
FIG. 9 is a diagram illustrating a specific operation of a conventional example.
FIG. 10 is a diagram illustrating a specific operation of a conventional example.
[Explanation of symbols]
8 D flip-flop
9 multiplier
10 Flip-flop RS
40-48 secondary station
10,110 Axis group manager
21, 121 axis servo system
21 ₁ , 121 ₁ motor
21 ₂ , 121 ₂ Position detector
31, 32, 33, 131 Numerical control device
31 ₁ , 32 ₁ , 131 ₁ transmission interface
31 ₂ , 32 ₂ , 131 ₂ CPU section
31 ₃ , 32 ₃ , 33 ₃ , 131 ₃ Speed command device
31 _4, 32 _4, 131 ₄ servo controller
31 _5, 32 _5, 33 _5, 131 ₅ buffer register
100 Primary station
131 ₆ Timer circuit
S1 Start signal
S2 Timer interrupt signal

Claims (2)

A numerical controller provided in plural for one axis group manager ,
A buffer register for temporarily storing data fetched from each unique frame;
A speed command device that gives a servo controller a speed command corresponding to a command value sent from the axis group manager,
Receives data for axis movement in a transfer format composed of a common frame that is commonly generated by the axis group manager and that corresponds to the numerical control device, and a unique frame that individually corresponds to each numerical control device. In a numerical controller of a distributed numerical control system that performs drive control of a single mechanical movement axis,
Each numerical controller is
When an activation signal is received, a timer interrupt signal is output after the transmission of the unique frame from the axis group manager to the numerical control device that requires fast data transmission within one data transmission cycle A timer circuit to
Each time a common frame is received, the speed command device is started by the data stored in the buffer register and the start signal is output to the timer circuit, and then the timer interrupt signal from the timer circuit is received. also numerical controller of the distributed numerical control system characterized by having a CPU unit that starts the speed command unit by the data stored in the buffer register. 2. A data transmission system using a numerical controller of a distributed numerical control system according to claim 1, wherein the axis manager transmits a unique frame more than once for a predetermined numerical controller in data transmission within the same period. A data transmission system.

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