JPH09261226A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the programmable controller that stores lots of I/O data while sampling the data at a high speed and minimizes a load of a transmission means. SOLUTION: An I/O controller 13 of the programmable controller 1 is provided with a dual port memory 131 storing input output data with time data added to them and an I/O trace controller 15 sampling trace data from data in the memory. Furthermore, this controller is provided with plural buffers storing the I/O trace data sequentially through automatic changeover and transferring data of a buffer fully occupied with data among the plural buffers to a host monitor 3 via a LAN interface 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a controller, and particularly to a traceback method for input / output data.

[0002]

2. Description of the Related Art A programmable controller enables input / output time chart creation and trend graph display by tracing back its input / output (I / O) data.

As a traceback method of this I / O data, a method of sampling the I / O data by a sampling program provided in the programmable controller and a method of sampling the I / O data by a host device connected to the programmable controller There is a method to do.

FIG. 3 shows a case where I / O data is sampled by a monitoring device as a host device. In a system in which a plurality of programmable controllers 1 are coupled to a controlled object through an I / O device 2 and each programmable controller 1 is network-coupled to a monitoring device 3 through a LAN, the programmable controller 1
The data input and output through the I / O device 2 is transmitted to the monitoring device 3 through the LAN and is sampled by the monitoring device 3.

[0005]

The method of sampling I / O data by the programmable controller itself enables high-speed sampling, but the I / O data is stored in the memory in the programmable controller. Depending on the capacity of the memory, the data may not be retained in the traceback for a long time.

Further, since the sampling of I / O data by a plurality of programmable controllers is not synchronized with each other, it is difficult to grasp the data correlation between the programmable controllers.

On the other hand, in the method of sampling by the host device, high-speed sampling becomes difficult because the data is transferred via the data transmission means such as LAN. Also,
Since the traceback I / O data is frequently transmitted to the transmission means, the load on the transmission means increases.

An object of the present invention is to provide a programmable controller capable of storing a large amount of I / O data while sampling at high speed and minimizing the load on transmission means.

[0009]

SUMMARY OF THE INVENTION The present invention includes an I / O controller for exchanging input / output data with an I / O device,
LAN for data transmission with host device via LAN
In a programmable controller having an interface, the I / O controller is provided with a dual port memory for temporarily storing input / output data by adding time data, and I / O trace is performed from the data temporarily stored in the dual port memory. I / O trace controller for sampling data for I / O is provided, and this I / O trace controller is provided with a plurality of buffers for sequentially and automatically storing I / O trace data having the time data in a plurality of buffers. The data in the buffer, which is full of I / O trace data in the buffer, is stored in the LA
It is characterized in that it comprises means for transmitting to the higher-level device via the N interface.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a configuration for traceback showing an embodiment of the present invention. The figure shows one of the programmable controllers 1, the CPU 11,
In addition to the memory 12, the I / O controller 13 and the LAN interface 14, the I / O trace controller 15 is connected by the PC bus.

The LAN interface 14 is used by the programmable controller 1 to transmit data to and from the monitoring device 3 through the LAN. The I / O controller 13 is used for the programmable controller 1 to transmit data to and from the plurality of I / O devices 2 through the LAN.

Here, the memory for temporarily storing the I / O data input / output to / from the I / O controller is the dual port memory 13 ₁ , and the dual port memory 13 ₁ is also accessed from the I / O trace controller 15. It is possible to transfer to the memory in the I / O trace controller 15.

The I / O trace controller 15 is an I / O trace controller.
The I / O trace data is sampled from the I / O data input / output via the O controller 13. The internal memory is of double buffer type, and when the first buffer is full of the trace data, Data is stored in the two buffers, and automatic switching is performed to alternately store the data in the two buffers.

In the above-described configuration, the normal I / O data processing by the programmable controller is, as shown by routes A and B, in the route A, the I / O controller 13 samples the input data at a constant cycle and outputs CP.
Send to U11 and memory 12, CPU1 on route B
The data calculated by 1 is output to the I / O device 2 at a constant cycle.

The I / O trace data from the I / O device 2 is stored in the memory in the I / O trace controller 15 via the dual port memory 13 ₁ in the I / O controller 13. When the I / O trace data is stored in this memory, as shown in FIG. 2, the sampling time data is added to the first word of the data and is also stored in the double buffer method.

When storing the I / O trace data by the double buffer method, when the first buffer 15 ₁ is full and the second buffer 15 ₂ is automatically switched, the I / O trace controller 15 The I / O trace data of the first buffer 15 ₁ is transmitted to the monitoring device 3 via the LAN. Similarly, when the second buffer 15 ₂ is full and data storage in the first buffer 15 ₁ is started, the I / O trace controller 15 is set to the second buffer 15 2.
And transmits the data in the buffer 15 ₂ to the monitoring device 3.

Therefore, in this embodiment, since data is transferred to the I / O trace controller 15 via the dual port memory 13 ₁ in the I / O controller 13, the trace can be performed in the shortest time in which the programmable controller can operate. Data can be collected.

Further, since the I / O trace controller 15 samples the I / O trace data, it is not necessary to prepare a data sampling program in the programmable controller 1.

Further, the I / O trace controller 15 stores I / O trace data alternately in two buffers, and monitors the data in the other buffer which is full while the data is stored in one buffer. 3, the memory in the I / O trace controller 15 is minimized, and the data transmission to the monitoring device 3 is intermittent so that the load on the LAN is reduced. In addition, a large amount of trace data can be stored by transmission to the monitoring device 3.

In the sampling of the I / O trace data, the time data is loaded in the first word, so that the data is transmitted from the plurality of programmable controllers to the monitoring device 3, but the time relationship between the plurality of data is also sampled. Is clarified, and the correlation between data can be surely maintained.

The number of buffers provided in the I / O trace controller is not limited to two, but a buffer having an equivalent capacity can be divided into three or more areas to divide the buffer into a capacity that is preferable in terms of transmission efficiency to the monitoring device 3. .

[0022]

As described above, according to the present invention, I / O
An I / O trace controller for sampling I / O trace data from the data temporarily stored in the controller dual port memory is provided, and this I / O trace controller automatically switches the I / O trace data to a plurality of buffers in order. Since the data in the buffer that was filled in and stored in the host computer is transmitted to the host device, the trace data can be collected in the shortest time that the programmable controller can operate and the minimum memory capacity. It is possible to reduce the transmission load and to store a large amount of data when transmitting to, and to secure the correlation with other data by the time data load.

[Brief description of drawings]

FIG. 1 is a configuration diagram for collecting trace data according to an embodiment of the present invention.

FIG. 2 is a diagram showing a storage mode of trace data according to the embodiment.

FIG. 3 is an example of a conventional method for sampling trace data using a monitoring device.

[Explanation of symbols]

1 ... Programmable controller 2 ... I / O device 3 ... Monitoring device 13 ... I / O controller 13 ₁ ... Dual port memory 14 ... LAN interface 15 ... I / O trace controller 15 ₁ , 15 ₂ ... Buffer

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Claims (1)

[Claims] 1. A programmable controller comprising an I / O controller for exchanging input / output data with an I / O device, and a LAN interface for transmitting data with a host device via a LAN. The / O controller is provided with a dual port memory for temporarily storing input / output data with time data added, and an I / O trace controller for sampling I / O trace data from the data temporarily stored in the dual port memory. This I / O trace controller is provided with a plurality of buffers for sequentially storing the I / O trace data having the time data in a plurality of buffers, and the I / O trace data of each buffer is full. The data in the buffer that has become the above is transmitted to the host device via the LAN interface. A programmable controller having means for transmitting.