JP4538740B2 - Programmable controller - Google Patents

Description

  The present invention relates to a programmable controller suitable for use in positioning control.

  FIG. 2 shows a configuration of a programmable controller used for positioning control. In FIG. 2, the programmable controller includes a CPU module 10 and a positioning module 20. The CPU module 10 is a module that controls the entire programmable controller, and issues a command to the positioning module 20 to control the control object 30 such as a motor or a driver.

  The positioning module 20 includes a CPU interface 21 that controls the interface of the CPU module 10, a trajectory calculation unit 22 that performs trajectory calculation and calculates data for controlling the control target 30, an operation table 23 that is referred to by the trajectory calculation unit 22, The output of the orbit calculation unit 22 is input, and the output unit 24 outputs a control signal such as a pulse signal or an analog signal to the control target 30. Note that the operation table 23 may not be used. Further, the output unit 24 may communicate with the control object 30 to control the control object 30.

  The CPU module 10 sets the target position and target speed, and requests the positioning module 20 to start the operation. The positioning module 20 calculates detailed trajectory data based on the target position and target speed, and outputs it to the output unit 24. The output unit 24 generates a control signal such as a pulse signal or an analog signal from the trajectory data, and outputs the control signal to the control object 30.

  FIG. 3 shows a connection relationship between the CPU module 10 and the positioning module 20. Reference numeral 40 denotes a backboard bus. The CPU module 10 and the positioning module 20 are connected to the backboard bus 40 and exchange data via the backboard bus 40.

  When the CPU module 10 stops due to an error, a fail signal 41 is transmitted to the positioning module 20 via the backboard bus 40. Since the CPU module 10 is stopped due to an error, the positioning module 20 can receive only a fail signal.

  For this reason, the positioning module 20 cannot know the content of the error. When receiving the fail signal, the positioning module 20 interrupts the positioning operation in operation for safety, decelerates the controlled object 30, and immediately stops it.

  For example, Patent Document 1 discloses a conventional positioning device.

JP 2003-330544 A

  However, such a programmable controller has the following problems. When an error of the CPU module 10 occurs, the positioning module 20 stops the control object 30 at the position where the error occurred, but depending on the case, the positioning module 20 stops at a position where the user does not want to stop, which hinders the subsequent work. There was a problem of coming.

  Accordingly, an object of the present invention is to provide a programmable controller capable of performing a preset operation after an error occurs.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
In a programmable controller that performs positioning control of a controlled object,
A CPU module that incorporates a processor, outputs command data, and outputs a fail signal that becomes valid when the processor becomes abnormal;
When the fail signal is input and when the fail signal is valid, an error time control unit that outputs preset command data;
When the fail signal is valid, a trajectory is calculated based on command data output by the error time control unit to generate a trajectory for the control target to move, and when the fail signal is not valid, A trajectory calculation unit that performs trajectory calculation based on command data output by the CPU module to generate and output a trajectory on which the control object moves; and
The output of the trajectory calculation section is input, and an output unit which generates a control signal based on the input data, and outputs to the control object,
Is provided. Since desired control can be performed when an error occurs, it is particularly effective when used for a programmable controller that controls a moving control object.

The invention according to claim 2 is the invention according to claim 1 ,
The error-time control unit outputs command data for positioning the control object at a predetermined position. The control object can be moved to an arbitrary position.

As is apparent from the above description, the present invention has the following effects.
According to the first and second aspects of the present invention, the controller includes an error control unit that operates when an error occurs in the CPU module, and generates a trajectory based on command data output by the error control unit when an error occurs. Output it.

  By registering in advance the control to be performed when an error occurs, any control can be performed when an error occurs, so that there is an effect that the control target can be safely controlled even when an error occurs. Further, by using it for positioning control for controlling a moving object, there is also an effect that it is possible to position the control target object at a safe and unobtrusive position when an error occurs.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a programmable controller according to the present invention. The same elements as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 1, the programmable controller includes a CPU module 10 and a positioning module 50. The positioning module 50 includes a CPU interface 51, a trajectory calculation unit 52, an operation table 23, an error time control unit 53, and an output unit 24.

  Data such as a target position and target speed and a fail signal are input to the CPU interface 51 from the CPU module 10. The error control unit 53 gives a command to the trajectory calculation unit 52 when an error occurs in the CPU module 10, and a fail signal 41 output from the CPU module 10 is input via the CPU interface 51.

  Data such as the target position and target speed from the CPU module 10 output by the CPU interface 51 and the output of the error time control unit 53 are input to the trajectory calculation unit 52. The trajectory calculation unit 52 refers to the operation table 23, calculates a detailed trajectory based on data from the CPU module 10 or an instruction from the error control unit 53, and outputs the calculated trajectory to the output unit 24. The output unit 24 generates a control signal from the trajectory and outputs it to the control object 30.

  Next, the operation of this embodiment will be described. When the CPU module 10 is normal, the fail signal 41 is in an inactive state (for example, high level). The CPU interface 51 outputs data sent from the CPU module 10 to the trajectory calculation unit 52. Further, the error time control unit 53 stops its operation.

  For this reason, the data from the CPU module 10 is input to the trajectory calculation unit 52. The trajectory calculation unit 52 generates a detailed trajectory based on the input data and outputs the detailed trajectory to the output unit 24.

  When an error occurs in the CPU module 10, the fail signal 41 becomes active (for example, low level). The CPU interface 51 blocks data sent from the CPU module 10 and does not output it to the trajectory calculation unit 52. Further, the error time control unit 53 starts its operation and outputs data such as a preset target position and target speed to the trajectory calculation unit 52.

  The trajectory calculation unit 52 generates a detailed trajectory by the output of the error time control unit 53 and outputs the detailed trajectory to the output unit 24. The output unit 24 generates a control signal based on the trajectory data and outputs the control signal to the control object 30.

  As described above, when the CPU module 10 is normal, the trajectory calculation unit 52 generates a detailed trajectory based on the data output from the CPU module 10, and when an abnormality occurs in the CPU module 10, Generate a detailed trajectory based on the output. For this reason, even if an error occurs in any state, the control object 30 can be positioned where there is no hindrance to the user's work.

  Possible operations when an error occurs include moving to a predetermined location, performing a predetermined pattern operation, and stopping on the spot.

  In this embodiment, when the fail signal 41 is inactive, the output of the error control unit 53 is not output, and when the fail signal 41 becomes active, the CPU interface 51 is not output. However, a changeover switch may be provided in the previous stage of the trajectory calculation unit 52 so that the output of the CPU interface 51 and the output of the error time control unit 53 are switched by a fail signal.

  In this embodiment, the programmable controller including the positioning module 50 has been described. However, the present invention is not limited to positioning control. For example, the present invention can be applied to a use for safely stopping the plant.

It is a block diagram which shows one Example of this invention. It is a block diagram of the conventional programmable controller for positioning control. It is a block diagram of a programmable controller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 CPU module 23 Operation | movement table 24 Output part 30 Control object 41 Fail signal 50 Positioning module 51 CPU interface 52 Orbit calculation part 53 Control part in error

Claims (2)

In a programmable controller that performs positioning control of a controlled object,
A CPU module that incorporates a processor, outputs command data, and outputs a fail signal that becomes valid when the processor becomes abnormal;
When the fail signal is input and when the fail signal is valid, an error time control unit that outputs preset command data;
When the fail signal is valid, a trajectory is calculated based on command data output by the error time control unit to generate a trajectory for the control target to move, and when the fail signal is not valid, A trajectory calculation unit that performs trajectory calculation based on command data output by the CPU module to generate and output a trajectory on which the control object moves; and
The output of the trajectory calculation section is input, and an output unit which generates a control signal based on the input data, and outputs to the control object,
A programmable controller comprising:   2. The programmable controller according to claim 1, wherein the error control unit outputs command data for positioning a control target object at a predetermined position.

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