JPH09297601A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely diagnose a controlled system without affecting the control operations concerning the controlled system by switching a normal standby mode to a diagnostic mode of the controlled system for a backup CPU. SOLUTION: Both a standby mode program WM and a diagnostic mode program DM which is prepared for diagnosis of a plant, i.e., a controlled system are simultaneously installed at a standby CPU 1b' that is prepared for backup of a control CPU 1a. Then a mode switching part 1e performs the switching between both programs WM and DM which are installed at the CPU 1b'. As a result, the controlled system can be surely diagnosed without giving any harmful effect to the control operations concerning the controlled system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device having a CPU for backup in addition to a CPU for performing normal operation control on a controlled object such as a plant.

[0002]

2. Description of the Related Art In a control device by a real-time computer system having a CPU for backup in addition to a CPU for performing normal operation control in order to perform operation control and monitoring of a plant to be controlled, A configuration for diagnosing the plant is shown in FIG.

That is, in FIG. 2, reference numeral 1 denotes a digital control device. This digital control device 1 is a control side CPU 1a for performing normal operation control, and a standby for backup for directly transmitting / receiving signals to / from the control side CPU 1a. Side CPU
1b, a switching relay 1c for switching these CPUs 1a and 1b to connect to an external data bus 2, and the CP described above.
Under the control of U1a and 1b, the signal input / output unit 1d directly exchanges signals with a plant (not shown) that is a control target.

A CR for displaying is provided on the data bus 2.
A monitoring panel 3 including a switch for instructing start / stop of T or plant is connected, while the digital control device 1 is connected.
The signal input / output unit 1d is connected with a detector 4 for detecting various states of the plant and an operator 5 for controlling the plant.

Generally, an apparatus for diagnosing the plant is
In many cases, process signals of the plant necessary for diagnosis are shared with signals for normal plant operation control and monitoring, and these signals are directly transmitted from the signal input / output unit 1d to the hard wired 7 plant. Either the first configuration for inputting to the diagnostic device 8 or the second configuration for inputting from the data bus 2 to the plant diagnostic device 10 via the interface device 9 as indicated by the dashed arrow A in the figure is adopted. I was doing. The plant diagnostic devices 8 and 10 having any of the above configurations are provided with dedicated display devices 11 and 12 for displaying diagnostic results and the like, respectively.

[0006]

However, in the case of adopting the above-mentioned first configuration, the configuration of the signal input / output unit 1d must be increased for signal branching, or a repeater, a contact amplification relay, etc. It is necessary to add more,
The hard-wired 7 cable must be laid separately.

Further, when the above-mentioned second structure is adopted, the existing data bus 2 can be utilized, so that no additional cables are required, but an interface device 9 for taking in process signals from the data bus 2 is required. In addition to the above, the communication traffic volume on the data bus 2 increases, so there is concern about a decrease in the data acquisition speed and a limitation on the number of data acquisitions. Furthermore, a monitoring panel related to the operation control of the original plant. There is concern that the responsiveness of signal display etc. in 3 may be deteriorated.

When considering the usage pattern of the plant diagnostic devices 8 and 10, there is no problem when continuous monitoring is required, but when it is used only for a specific period such as at the time of trial operation or periodical inspection, or in the usual case. If the system is used only for a short time during the operation period, for example, when calculating the performance of the plant once a day, the system is expensive and expensive, regardless of the configuration of the first and second configurations. There was a problem that became.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the device cost with a simple system configuration and also affect the control operation relating to the original control target. It is an object of the present invention to provide a control device capable of surely executing a diagnosis of a controlled object.

[0010]

According to the first aspect of the present invention,
In a control device having a CPU for backup in addition to a CPU for performing normal operation control for a controlled object, a switching means for switching the backup CPU from a normal standby mode to a diagnostic mode for diagnosing the controlled object. It is characterized by having.

With this configuration, the CPU for backup performs diagnosis of the controlled object inside the control device, so that installation of a dedicated interface or laying of a cable is unnecessary and the system configuration is simplified. Turned into
Not only the device cost can be reduced, but also the diagnosis of the controlled object can be executed reliably without increasing the communication traffic volume on the data bus and adversely affecting the control operation of the original controlled object. You can

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the conceptual configuration thereof, and since the basic configuration of the digital control apparatus 1'itself is almost the same as that of the digital control apparatus 1 of FIG. 2, the same parts are designated by the same reference numerals. The description is omitted.

A standby mode program WM and a diagnostic mode program DM for diagnosing the plant to be controlled can be simultaneously installed in the standby CPU 1b 'provided for backup of the control CPU 1a. The mode switching unit 1 is assumed to perform mode switching between the standby mode program WM and the diagnostic mode program DM installed in the standby side CPU 1b '.
e is further provided.

However, when the diagnostic mode program DM of the standby CPU 1b 'is started and the diagnostic process is executed, the diagnostic result is from the switching relay 1c to the data bus 2 as indicated by the broken arrow B in the figure. It is displayed and output on the monitoring board 3'through.

In the above configuration, the standby mode program WM has been followed until then, for example, by manual input by an operator of the digital control apparatus 1'or by automatic input according to setting conditions such as time. Control side CPU 1a
Standby side C that was performing standby processing similar to the above
It is assumed that the mode switching unit 1e switches and selects the diagnostic mode program DM for the PU 1b '.

In this case, the stand-by CPU 1b 'immediately stops the stand-by process based on the stand-by mode program WM until then, and instead selects the diagnostic mode program DM selected.
And executes diagnostic processing such as abnormality diagnosis and performance evaluation of the plant to be controlled. Then, when the diagnosis process is completed and the diagnosis result is obtained, the obtained diagnosis result is displayed and output from the monitoring panel 3'from the switching relay 1c via the data bus 2, and again in place of the diagnosis mode program DM in the standby mode. It automatically returns to the standby mode in which the same calculation as that of the control side CPU 1a based on the program WM is performed.

As described above, since the diagnosis result is also displayed on the monitor board 3 ', the structure of the display device 11 or 12 can be simplified as compared with the structure shown in FIG. Since the diagnosis result can be confirmed together with the plant control status, it is possible to reduce the burden on the operator of the digital control apparatus 1 '.

In the above embodiment, the standby CPU
Although it has been described that the two programs of the standby mode program WM and the diagnostic mode program DM are installed in the 1b ', they do not necessarily have to be installed in the both at the same time. The program to be executed may be installed. By doing this, the CP on the standby side
Even if U1b 'has a small memory storage capacity in which the program is installed, the above switching operation can be realized.

[0019]

As described above, according to the present invention, the CPU for backup performs the diagnosis of the controlled object inside the control device, so that the installation of a dedicated interface or the laying of a cable is unnecessary. Not only can the system configuration be simplified and the device cost be reduced, but the control target can also be reliably controlled without increasing the communication traffic volume on the data bus and adversely affecting the control operation related to the original control target. The diagnosis of can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a conceptual configuration of a control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a conceptual configuration of a general plant control device.

[Explanation of symbols]

 1, 1 '... Digital control device 1a ... Control side CPU 1b, 1b' ... Standby side CPU 1c ... Switching relay 1d ... Signal input / output section 1e ... Mode switching section 2 ... Data bus 3, 3 '... Monitoring board 4 ... Detector 5 ... Operator 7 ... Hard-wired (cable) 8, 10 ... Plant diagnostic device 9 ... Interface device 11, 12 ... Display device WM ... Standby mode program DM ... Diagnostic mode program

Claims (1)

[Claims] 1. A control device having a CPU for backup in addition to a CPU for performing normal operation control for a controlled object, and a diagnostic mode for diagnosing the controlled object from a normal standby mode for the backup CPU. A control device having switching means for switching to.