JPH04280400A - Signal input device - Google Patents

Abstract

PURPOSE:To develop the signal input device and to more improve reliability by applying various functions such as a function for detecting signal, input processing abnormality or the like and a function for informing the detected results to the signal input device itself. CONSTITUTION:Plural analog signals 1 transmitted and inputted from the outside through a connector 45 to this device are successively switched by multiplexers 2 and 4 on respectively different paths and further converted to digital signals by A/D converters 3 and 5 in the next step. A local CPU 36 reads the digital signals corresponding to the inputted analog signals from the abovementioned both paths through a local bus 37 and calculates the difference and in the case of abnormality when the difference is larger than a prescribed value, a signal showing it is outputted to a main computer 40 together with the above- mentioned both signals. Further, an alarm signal is outputted to an abnormality processing logic & state display circuit 44. Thus, the alarm is displayed corresponding to the contents of the abnormality.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal input device for analog or digital signals suitable for a computer-based monitoring and control system such as a plant control device, and more particularly to an improvement in signal input processing.

0002

2. Description of the Related Art Conventional analog signal input devices for computer-based monitoring and control systems only perform multiplexing of 16-point voltage signals, A/D (analog/digital) conversion, and the like. Conventionally, in this type of analog signal input device, even if it is a relatively advanced device that has a microcomputer on its own device, it has implemented intelligent A/D conversion operations, checked the input signal range, and However, in order to improve the reliability of signal input processing, it is necessary to detect and transmit the same signal outside the computer system including the signal input device. Three transmitters are installed, all signals transmitted from these are input into a computer, an intermediate value is selected, and this is monitored and
It was commonly used as a control signal.

On the other hand, conventional digital signal input devices for computer-based monitoring and control systems only perform electrical isolation between the outside and the computer using a photocoupler, convert the signal voltage level, and transmit the signal to the computer. was. Conventionally, in order to improve the reliability of signal input processing in this type of digital signal input device, the same signal is amplified into two or three points using an electromagnetic relay, and all of these are input into a computer. In the case of two-point input, for example, the two
A method was used in which the device was turned on when two signals were both turned on, or it was turned on when either one of two signals was turned on. In addition, in the case of three-point input, for example, when two or more signals are turned on, it is determined that the signal is on.

Next, regarding abnormalities in the power supply within an analog signal input device, conventional methods have been limited to monitoring the voltage of the power supply supplied to the input device from the outside; Moreover, none had a function to detect abnormalities such as short circuits in internal circuits. This is exactly the same with conventional digital signal input devices.

[0005]

[Problems to be Solved by the Invention] In recent years, there has been an increasing demand for improved reliability of computer-based monitoring and control systems. In response to these demands, the computer itself is often dealt with by multiplexing it, but for signal input devices for analog or digital signals, it is not possible to solve the problem by multiplexing the computer itself. This was a common response.

The present invention has been made in view of the above circumstances, and its purpose is to provide the input device itself with various abnormality detection functions.
Another object of the present invention is to provide a signal input device that is provided with a function of notifying the detection results, thereby realizing sophistication of the device and further improving reliability.

[0007]

[Means and Effects for Solving the Problems] In order to make signal input processing, for example, analog signal input processing of an analog signal input device more reliable, the present invention doubles all analog input signals inside the device. respectively through the route of A/
The configuration is such that a D converter converts the signal into a digital signal, and the values of both digital signals are read and compared and checked. This check operation is performed, for example, by the processing of a local CPU (microcomputer) installed separately from the main computer, and if the deviation of the values of both digital input signals read is within a certain range, it is normal. If it is not included, it is considered abnormal.

Further, in the present invention, when an abnormality is detected in the above checking operation, an abnormality signal (input device abnormality signal) notifying the fact is sent to the main computer together with both corresponding signals (both digital signals). At the same time, it is configured to issue an alarm signal. This alarm signal is supplied to the status display means, and an alarm is displayed.

The present invention also provides a means for detecting the presence or absence of a disconnection of a connector used at a point where a signal is inputted to the apparatus from the outside (connector connection monitoring means), and a means for detecting an abnormality in the power supply inside the apparatus. (DC/DC converter output abnormality monitoring means) is provided, and even when an abnormality is detected in the connector or the power supply, an alarm signal is issued to the status display means and an alarm display is performed.

Further, in order to facilitate analysis when an abnormality is detected, the present invention provides a panel on the front surface of the signal input device, attaches a plurality of indicator lamps (for example, LEDs), and uses a status display means to display information according to the content of the abnormality. By switching the display lamps, it becomes easier to identify the abnormality generating device and furthermore to determine the nature of the abnormality.

Furthermore, in order to make the digital signal input processing of the digital signal input device more reliable, the present invention inputs all the digital input signals through dual paths inside the device, and the values of both input signals are respectively They are read and compared, and if the deviation between the values of both signals is within a certain range, it is determined to be normal, and if it is not, it is determined to be abnormal. The other configurations are the same as those of the analog signal input device described above.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2, taking as an example the case where it is applied to an analog signal input device in a monitoring and control system.

FIG. 1 is a block diagram showing the configuration of an analog signal input device. In FIG. 1, 1 is an analog signal transmitted and input from the outside via a connector, 2 and 4 are multiplexers that sequentially switch a plurality of commonly input analog signals 1 under the control of the local CPU, and 3 and 5 are multiplexers. Signals switched and output by 2 and 4 (
This is an A/D (analog/digital) converter that converts an analog signal into a digital signal. In this embodiment, the above combination of multiplexer 2 and A/D converter 3 and multiplexer 4 and A/D converter 5 are combined.
This combination realizes duplication of input signal reading and processing paths (the former is route #1 and the latter is route #2).

6 compares the deviation of the values of the two input signals (digital signals) inputted from the above two routes via the local bus 7, and when the deviation is normal and within a predetermined value, a predetermined value is determined. This is a local CPU (microcomputer) that transmits one signal to a main computer 10, which will be described later. The local CPU 6 also transmits both input signals and an input device abnormality signal indicating an input device abnormality to the main computer 10 when the deviation is outside a predetermined value, and sends an alarm signal to the abnormality processing logic & status display circuit 10. Output. 7 is a local bus for configuring the CPU circuit on this device.

8 is a register buffer & bus controller for interfacing between the local bus 7 on this device and the computer bus 9; 9 is a standard, for example, IE
A computer bus 10 conforming to EE796 is a computer (main computer) for performing main arithmetic processing of the monitoring/control system. The main computer 10 performs, for example, processing for selecting signals to be used in calculations, switching processing for a computer serving as a control system in a system in which computers are multiplexed, etc., based on various abnormality occurrence information sent from this device and the like. .

Reference numeral 11 denotes a DC/DC converter (DC voltage converter) provided to receive a DC power supply supplied from the outside and generate a DC power supply of a voltage required by the internal circuit. In this embodiment, the DC/DC converter 11 is
It receives an external +5V power supply and generates a ±15V power supply.

12 is the output of the DC/DC converter 11 (
±15V) to determine its normality/abnormality.
This is a DC converter output abnormality monitoring unit. This output abnormality monitoring unit 12 detects an abnormality when the output of the DC/DC converter 11 deviates from the reference value (±15V) by a predetermined value or more.
An alarm signal is output to the abnormality processing logic & status display circuit 14. Reference numeral 13 denotes a connector connection monitoring section for monitoring and determining the connection state of the connector (analog input connector) 15. The connector connection monitoring unit 13 outputs an alarm signal to the abnormality processing logic and status display circuit 14 when there is no analog input connector insertion signal indicating that the connector 15 is correctly connected.

Reference numeral 14 denotes an abnormality processing logic and status display circuit that receives alarm signals from various parts within the apparatus and displays (lights up) an alarm on the front panel of the apparatus. The abnormality processing logic & status display circuit 14 is designed to internally hold information on the occurrence of an abnormality in order to facilitate analysis processing when an abnormality occurs, and to clear this information when it is no longer needed. The alarm reset signal is received. Reference numeral 15 denotes a connector (analog input connector) for connecting this device to an external analog signal sending source via a cable or the like.

FIG. 2 is a diagram showing an example of the front panel of the analog signal input device shown in FIG. In FIG. 2, 21
22 is a push button switch for resetting the alarm, and 22 is an indicator lamp (usually an LED) that lights up when the power supply inside the device is normal and goes off when there is an abnormality. Reference numeral 23 denotes an indicator lamp (input data status indicator lamp) that lights up when an alarm occurs. A plurality of display lamps are provided and the lamps to be lit are divided depending on the nature of the abnormality, thereby making it possible to grasp the nature of the abnormality at an early stage.

Next, the analog signal input device (first
The operation of the example) will be explained. First, connect connector 1 from the outside.
The analog signal 1 at multiple points transmitted and input via 5 is
Under the control of the local CPU 6, the signals are sequentially switched by multiplexers 2 and 4 on different routes (routes #1 and #2) and output to A/D converters 3 and 5, respectively. The A/D converters 3 and 5 convert analog signals (7) switched and output from the multiplexers 2 and 4 into digital signals.

[0021] The local CPU 6 is connected to the A/D converter 3.
, 5 for the same analog signal 1 are read via the local bus 7, and the deviation thereof is determined. Then, the local CPU 6 checks whether the calculated deviation is greater than or equal to a predetermined value.

If the obtained deviation is normal and within a predetermined value, the local CPU 6 sends a predetermined one of the two signals (digital signals) read from the above two paths to the local bus. 7. Transfer to main computer 10 via register buffer & bus controller 8 and computer bus 9.

On the other hand, when the calculated deviation is abnormal by a predetermined value, the local CPU 6 sends an input device abnormality signal indicating an input device abnormality to the local bus 7 along with the above two signals.
, register buffer & bus controller 8, and computer bus 9 to the main computer 10. here,
It is also possible to use the input device abnormality signal as an interrupt signal, for example, to interrupt the main computer 10 to detect an abnormality using an interrupt signal line normally provided on the computer bus 9.

Furthermore, the local CPU 6 is connected to the main computer 1.
At the same time as the input device abnormality signal is output to the input device 0, the alarm signal is sent to the abnormality processing logic & status display circuit 1 via the local bus 7.
Output to 4. The abnormality processing logic & status display circuit 14 internally holds (the status of) the alarm signal from the local CPU 6 as abnormality occurrence information corresponding to its output source, and also stores the alarm signal (state) from the local CPU 6 as abnormality occurrence information. Among the plurality of display lamps 23, the lamp corresponding to the content of the abnormality is turned on.

Now, in the analog signal input device shown in FIG. 1, the DC/DC converter 11 converts the +5V DC power supplied from an external power supply into the ±15V DC power supply used internally.
Generates V power. The DC/DC converter output abnormality monitoring unit 12 monitors the output of the DC/DC converter 11, and determines whether the output is outside a predetermined value or not.
Determine whether the 15V power supply (DC/DC converter 11) is normal or abnormal. When an abnormality is determined, the output abnormality monitoring section 12 outputs an alarm signal to that effect to the abnormality processing logic and status display circuit 14. The abnormality processing logic & status display circuit 14 receives (the status of) the alarm signal from the output abnormality monitoring unit 12.
is internally held as abnormality occurrence information corresponding to the output source, and the display lamp 22 attached to the front panel shown in FIG. 2 is turned off to notify of an abnormality in the power supply within the apparatus.

In the analog signal input device shown in FIG. The insertion signal is monitored and determined. If the analog input connector insertion signal is not detected, the connector connection monitoring section 13 assumes that the connector 15 is not properly connected, and outputs an alarm signal to that effect to the abnormality processing logic and status display circuit 14. Abnormality processing logic & status display circuit 1
4 internally holds (the state of) the alarm signal from the connector connection monitoring section 13 as abnormality occurrence information corresponding to its output source, and also displays one of the plurality of display lamps 23 attached to the front panel shown in FIG. , lights up the lamp corresponding to the abnormality.

Now, when an analysis process is performed when an abnormality occurs based on the display state of the front panel shown in FIG. 2, and the abnormality occurrence information held in the abnormality processing logic & status display circuit 14 is no longer needed. , the operator turns on the push button switch 21 on the front panel to generate an alarm reset signal. This alarm reset signal is supplied to the abnormality processing logic and status display circuit 14, thereby clearing the abnormality occurrence information held within the circuit 14.

Note that the abnormality processing logic & status display circuit 1
As a means for outputting an alarm signal to 4, it is also possible to further provide a monitoring means for monitoring the normality/abnormality of the power supply (+5V in this case) supplied from the outside.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4, taking as an example the case where it is applied to a digital signal input device in a monitoring and control system. FIG. 3 is a block diagram showing the configuration of the digital signal input device. In FIG. 3, 31 is a digital signal input from the outside, 32 and 34 are photocouplers for electrical insulation from the outside, and 33 and 35 are interfaces with the local CPU 36 through a local bus 37. This is an input buffer for reading. In this embodiment, the above photo coupler 3
2 and the input buffer 33, and the combination of the photocoupler 34 and the input buffer 35, the input signal reading processing path is duplicated (the former is route #1 and the latter is route #2).

36 is a local CPU, 37 is a local bus, 38 is a register buffer & bus controller,
39 is a computer bus, and 40 is a main computer. These local CPU 36, local bus 37, register buffer & bus controller 38, computer bus 39, and main computer 40 are the local CPUs shown in FIG.
6, local bus 7, register buffer & bus controller 8, computer bus 9, and main computer 10.

41 is a DC/DC converter, 42 is a DC
/DC converter output abnormality monitoring section, 43 is a connector connection monitoring section. These DC/DC converters 41, DC
/DC converter output abnormality monitoring section 42 and connector connection monitoring section 43 correspond to DC/DC converter 11, DC/DC converter output abnormality monitoring section 12, and connector connection monitoring section 13 in FIG. 1, respectively. 44 is an abnormality processing logic and status display circuit (similar to the abnormality processing logic and status display circuit 14 in FIG. 1) that receives alarm signals from various parts within the apparatus and displays (lights up) an alarm on the front panel of the apparatus. be. Reference numeral 45 denotes a connector (digital input connector) for connecting the present device to an external digital signal sending source via a cable or the like.

FIG. 4 is a diagram showing an example of the front panel of the digital signal input device shown in FIG. In FIG. 4, 51
2 is a push button switch for alarm reset, and 52 and 53 are indicator lamps, which are used in the same way as the push button switch 21 and indicator lamps 22 and 23 in FIG. 54 is a rotary switch used to switch which signal group is displayed for the group of display lamps 55. 55 is a display lamp (input data status display lamp) for displaying the status of the input signal in a group of 8 points, for example.
By switching with the rotary switch 54,
The two reading processing routes mentioned earlier (route #1, #2
) can also be displayed.

Next, the operation of the digital signal input device (second embodiment) shown in FIG. 3 will be explained, focusing on the differences from the analog signal input device shown in FIG. First, connect the connector 45 from the outside.
The digital signals 31 transmitted and input via the photocouplers 3 on different routes (routes #1 and #2)
2 and 34 provide electrical insulation from the outside, and are supplied as input signals to input buffers 33 and 35, respectively. The local CPU 36 reads both of the above-mentioned input signals (digital signals) from the input buffers 33 and 35 via the local bus 37, and calculates the deviation thereof. Then, the local CPU 36 checks whether the calculated deviation is greater than or equal to a predetermined value.

Local CPU according to the above check results
36 and the operation of the abnormality processing logic & status display circuit 44 when an input device abnormality is detected are performed by the local CPU 6 and the abnormality processing logic & status display circuit 1 of FIG.
This is the same as 4, and the explanation will be omitted. Also, when the DC/DC converter output abnormality monitoring unit 42 detects an output abnormality of the DC/DC converter 41, and the connector connection monitoring unit 43
The operation of the abnormality processing logic & status display circuit 44 when a connection abnormality is detected in the connector 45 is as shown in FIG.
This is similar to the operation of the abnormality processing logic and status display circuit 14 when the DC converter output abnormality monitoring section 12 detects an abnormality in the output of the DC/DC converter 11 and when the connector connection monitoring section 13 detects an abnormality in the connection of the connector 15. The explanation will also be omitted.

However, the abnormality processing logic and status display circuit 44 in the device of this embodiment shown in FIG. C
Figure 4 shows the state of the digital signal read into the PU36.
According to the switching by the rotary switch 54 shown in
It is possible to display the information using the display lamp 55.

[0036]

Effects of the Invention As detailed above, according to the present invention, an input path for converting an analog signal sent from the outside into a digital signal and reading it (in the case of an analog signal input device) or a digital signal sent from the outside. An anomaly detection function that provides a double input path (in the case of a digital signal input device) for inputting and reading and detects an abnormality based on the deviation of the value of the digital signal read through both input paths; In addition to providing a function to detect an abnormality in the power supply inside the device and a function to detect a poor connection of the input connector, it also has a function to notify the abnormality detection result by an alarm display, etc., so that the signal input processing of the signal input device can be easily performed. Sophistication can be realized, and reliability can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an analog signal input device showing a first embodiment of the present invention.

FIG. 2 is a front panel diagram of the analog signal input device of FIG. 1.

FIG. 3 is a block configuration diagram of a digital signal input device showing a second embodiment of the present invention.

FIG. 4 is a front panel diagram of the digital signal input device of FIG. 3;

[Explanation of symbols]

1, 31...Analog signal (analog input signal), 2, 4
...Multiplexer, 3,5...A/D converter, 6,3
6...Local CPU, 7,37...Local bus, 9,3
9...Computer bus, 10,40...Main computer, 11,4
1... DC/DC converter, 12, 42... DC/DC converter output abnormality monitoring section, 13, 43... Connector connection monitoring section, 14, 44... Abnormality processing logic & status display circuit,
15, 45... Connector, 21, 51... Push button switch, 22, 23, 52, 53, 55... Display lamp, 54
...Rotary switch.

Claims (6)

[Claims] [Claim 1] Two input paths for converting an analog input signal sent from the outside into a digital signal and reading the digital signal.
processing means for determining the deviation between the values of the digital signals read through both input paths and outputting an input device abnormality signal to the main computer and outputting an alarm signal if the deviation is greater than a predetermined value; , and status display means for inputting an alarm signal from the processing means and displaying an alarm. 2. Further comprising a DC/DC converter output monitoring means for monitoring the output of the DC/DC converter built into the device and outputting an alarm signal if the output exceeds a predetermined value,
2. The analog signal input device according to claim 1, wherein said status display means inputs an alarm signal from said DC/DC converter output monitoring means and displays an alarm. 3. Connector connection monitoring means for monitoring the connection state of a connector for transmitting the analog input signal to the inside of the device and outputting an alarm signal in the event of an abnormal connection; 3. The analog signal input device according to claim 1, wherein an alarm signal from the connection monitoring means is input and an alarm is displayed. [Claim 4] Providing double input paths for inputting and reading digital input signals sent from the outside, and determining the deviation of the values of the digital signals read through both input paths and calculating the deviation when the value is greater than a predetermined value. is characterized in that it is provided with processing means for outputting an input device abnormality signal to the main computer and outputting an alarm signal, and at least a status display means for inputting the alarm signal from the processing means and displaying an alarm. Digital signal input device. 5. Further comprising a DC/DC converter output monitoring means for monitoring the output of the DC/DC converter built into the device and outputting an alarm signal if the output exceeds a predetermined value,
5. The digital signal input device according to claim 4, wherein said status display means inputs an alarm signal from said DC/DC converter output monitoring means and displays an alarm. 6. Connector connection monitoring means for monitoring the connection state of a connector for transmitting the digital input signal to the inside of the device and outputting an alarm signal in the event of an abnormal connection; 6. The digital signal input device according to claim 4, wherein the digital signal input device inputs an alarm signal from the connection monitoring means and displays the alarm.