JP2623392B2 - Sensing device and output correction method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensing device which is used in a fire alarm device or the like, senses a predetermined physical quantity such as smoke density or temperature, and outputs a sensing result, and a method of correcting the output. You.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 61-247919.
There are known sensors as disclosed in US Pat. This sensor creates a pseudo state corresponding to a predetermined value of the physical quantity, detects a pseudo output value in the pseudo state and a zero output value in a state where the physical quantity is zero, and detects the pseudo output value and the zero output value. Is used to calculate the slope of the straight line that gives the actual output characteristics of the sensor. Thereafter, when a sensor output value corresponding to an arbitrary physical quantity is obtained, a physical quantity corresponding to the sensor output value is obtained in accordance with the actual output characteristic given by the slope of the straight line calculated as described above, and a predetermined schedule is obtained from the physical quantity. An analog signal is output by obtaining a corrected output value according to a correct output characteristic (reference output characteristic). Thus, it is intended to output an analog signal according to a predetermined correct output characteristic (reference output characteristic) regardless of the actual output characteristic.

[0003]

However, in the above-described conventional sensor, the pseudo output value and the zero output value are actually detected using, for example, an LED or the like in the test mode, and then the data giving the actual output characteristic is obtained. When the actual output characteristics are changed, the pseudo output value and the zero output value must be detected by using an actual device such as an LED. There was a drawback of lacking in sex. In addition, the reference output characteristic (reference output characteristic) may vary depending on the system and the situation at the site, and in this case, the reference output characteristic needs to be changed according to the system and the situation at the site. However, it is not easy to deal with the case where the reference output characteristic is changed.

According to the present invention, data which gives actual output characteristics can be arbitrarily changed and set at the discretion of an operator without actually detecting the data, and a reference output used when performing output correction. It is an object of the present invention to provide a sensing device having extremely high operability and extremely high flexibility, and a method of correcting the output of the sensing device, which can easily cope with a change in characteristics.

[0005]

To achieve the above object, the present invention provides a detecting means for detecting a predetermined physical quantity and outputting a predetermined analog level signal, and converting the analog level signal from the detecting means into a digital signal. A / D conversion means for converting and outputting as a detection signal, output characteristic specification information for specifying a predetermined output characteristic, and correction information for correcting a detection signal from the A / D conversion means so as to follow the predetermined output characteristic And the output characteristic specification information and the correction information stored in the non-volatile memory are read from the non-volatile memory, and the A is read based on the output characteristic specification information and the correction information. A central processing means for correcting the detection signal from the / D conversion means so as to comply with the predetermined output characteristic, and an external detection signal corrected by the central processing means. And a transmission means for transmitting,
The nonvolatile memory stores the output characteristic designation information and the correction information.
It is characterized in that it is configured to be able to rewrite any information at any time .

[0006]

According to the present invention, output characteristic designation information and correction information used for correcting a detection signal from the A / D conversion means are held in a non-volatile memory in a readable / writable manner. As a result, when the situation at the site or the situation of the sensing device itself changes and it becomes necessary to change the predetermined output characteristic or the actual output characteristic according to the situation or the like, the output currently held in the nonvolatile memory is output. The characteristic designation information and the correction information can be rewritten and changed.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an embodiment of the sensing device according to the present invention. The detecting device 1 shown in FIG. 1 detects a physical quantity such as smoke density or heat generated in a fire or the like and outputs an analog level signal, and converts the analog level signal from the detecting section 10 into a digital signal. An A / D converter 11 for outputting a detection signal, a central processing unit 3 for performing predetermined processing on a detection signal detected by the detection unit 10 and transmitted from the A / D converter 11 via the interface 12, And a transmission unit 17 which receives a processing result from the central processing unit 3 via the interface 16 and sends it out to a receiving device (not shown) via the transmission path 2. Have.

The central processing unit 3 includes a processor unit (CPU main body 2) using, for example, a microprocessor.
1, ROM 22, RAM 23).
The detection signal sent from the D converter 11 is subjected to predetermined correction processing, a correction output value is obtained, and the correction output value is output to the transmission unit 17 via the interface 16. The storage unit 15 is composed of a non-volatile memory, for example, an EEPROM, in which data necessary for the central processing unit 3 to perform a correction process on a detection signal is written and read. .

That is, the central processing unit 3 performs a process of correcting a detection signal (actual output value) for a physical quantity such as the current smoke density in accordance with a correct output characteristic (reference output characteristic). More specifically, the central processing unit 3
Is performed as follows. When the basic output value (reference output characteristic) for the physical quantity (smoke density, etc.) x is y1 and the actual output value of the sensing device for the physical quantity (smoke density, etc.) x is y2, y1 and y2 are respectively It is represented by the following equation (Equation 1, Equation 2).

[0010]

## EQU1 ## y1 = ax + b

[0011]

## EQU2 ## y2 = cx + d

In Equation 1, a and b are parameters of the reference output characteristic, and represent the slope and the offset, respectively. In Equation 2, c and d are parameters of the actual output characteristics (actual output characteristics) of the sensing device, and represent the inclination and the offset, respectively. FIG. 2 shows a specific example of y1 and y2. ing.

In order to correct the actual output value y2 according to the reference output characteristic y1, the following formula is required. Note that y3 is an output correction amount.

[0014]

Y3 = (ac) x + (bd)

By the way, although the physical quantity x is included in the equation 3, the physical quantity x can be deleted by substituting the equation 2 into the equation 3. In this case, the equation 3 is expressed by the following equation. Can be transformed into

[0016]

Y3 = (ac) (y2-d) / c + (b-d)

As can be seen from Equation 4, the output correction amount y3
Is determined based on the actual output value y2 of the sensing device 1 if the parameters a, b, c, and d are known. Thus, the corrected output value y is obtained as in the following equation.

[0018]

## EQU5 ## y = y2 + y3

When the correction processing is performed according to the equations (4) and (5), the slope a and the offset b are written in the storage section 15 as information for designating the reference output characteristic as output characteristic information. For correcting the detection signal from the detector 12 (that is, the actual output value) so as to follow the reference output characteristic, the slope c, the offset d, and the correction values (ac), (b-d) of the actual output characteristic. ) Is written as correction information. The central processing unit 3 includes a storage unit 1
The above data is read out from 5 and the operations of equations 4 and 5 are performed. Note that such an arithmetic processing program is stored in advance in, for example, the ROM 22, and the CPU main body 21 executes the above arithmetic using the data read from the storage unit 15 and using the RAM 23 as a work area according to this program. ing.

In the sensing device 1 having such a configuration, when the sensing device 1 is actually used, the storage unit 1 which is a nonvolatile memory is used.
5, More specifically, in the EEPROM, required data, that is, the output characteristic information a and b and the correction information c,
d, (ac) and (bd) are written. This writing can be performed by an external memory rewriting device (for example, a personal computer) 20. That is, the output characteristic information a and b can be set as data according to the system and the situation at the site, and written by the memory rewriting device 20. Also,
Regarding the correction information c, d, (ac), (bd),
After the actual output characteristics of the sensing device 1 are detected in advance, the data can be set as data using the output characteristic information, and similarly written by the memory rewriting device 20. Note that the slope c and offset d of the actual output characteristics are changed,
For setting, for example, in a test mode, an actual detection operation is performed using an LED or the like, and the data is stored in, for example, C
Although the data can be written into the EEPROM via the PU main body 21, in the present embodiment, these data are further changed and set arbitrarily at the discretion of the operator by the memory rewriting device 20 without actually performing the detecting operation. You can also.

After the required data is written in the storage unit 15 in this manner, the detection unit 10 detects physical quantities such as smoke density and heat, and the detection signal of this physical quantity, that is, the actual output value y2 is A When input to the central processing unit 3 via the / D converter 11 and the interface 12, the central processing unit 3
The required data is read from the storage unit 15 and a correction process is performed on the actual output value y2. More specifically, the CPU main body 21 of the central processing unit 3 follows the arithmetic processing program stored in the ROM 22, uses the RAM 23 as a work area, and uses the actual output value y2 to calculate the output correction amount y3 After that, the output correction amount y3 is added to the output value y2 to obtain a corrected output value y, which is transmitted to the receiving device via the interface 16 and the transmission path 17.

As described above, in the present embodiment, even if the detected actual output value y2 does not follow the reference output characteristic due to variations in the characteristics of the sensing device 1, this is automatically corrected. Thus, the output value y according to the reference output characteristic can be always output. Accordingly, there is no need to set the sensitivity in the detection unit 10 and the like, and the product can be stably supplied as a product having the same characteristics. In addition, since it is not necessary to perform the correction process on the receiving device side, the burden on the receiving device side can be reduced.

Further, in this embodiment, all the data necessary for the correction processing is written to and read from the readable / writable storage unit 15, specifically, the EEPROM. Can be easily changed by the external memory rewriting device 20. That is, when the situation at the site where the sensing device 1 is set or the situation of the sensing device 1 itself changes, it is necessary to change the reference output characteristic or the actual output characteristic according to the situation or the like. Such a change is extremely simple and easy only by rewriting the data of the output characteristic information a and b of the EEPROM and the data of the correction information c, d (ac) and (bd) by the memory rewriting device 20. You just have to work. More specifically, when the current condition of the sensing device 1 is changed, it is necessary to change the reference output characteristic. Such a change is made by changing the output characteristic information a, b is rewritten, and (a
Only the data of -c) and (b-d) need to be rewritten.
Also, when the situation of the sensing device 1 itself changes, the EE
The correction information c, d , (a-
This can be dealt with simply by rewriting the data of c) and (bd). At this time, as for c and d, L
This can be detected using an ED or the like and written into the EEPROM, but can be changed by the memory rewriting device 20 based on the judgment of the operator without using the LED or the like. Further, since the storage unit 15 is a non-volatile memory, the output characteristic information and the correction information are not erased even in a power-off state such as a power failure.

In the above-described embodiment, the rewriting of the storage unit 15 and the like are performed by the external memory rewriting device 20. However, depending on the type of the memory constituting the storage unit 15, the external memory may be rewritten. Instead of using the rewriting device 20, it is also possible to cause the CPU main body 21 (or console or the like) of the central processing unit 3 to perform rewriting or the like.

[0025]

According to the present invention as described above,
Since output characteristic designation information and correction information used for performing correction on the detection signal from the A / D conversion means are held in a non-volatile memory in a readable / writable manner,
Even when the situation of the site or the situation of the sensing device itself changes and it becomes necessary to change the predetermined output characteristic or actual output characteristic according to the situation, etc., the output characteristic designation currently held in the nonvolatile memory It is only necessary to rewrite and change the information and the correction information. Therefore, a predetermined output characteristic (reference output characteristic)
Not only the change of the actual output characteristics but also the change of the actual output characteristics can be handled very easily with good operability and flexibility.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a sensing device according to the present invention.

FIG. 2 is a diagram illustrating an example of a reference output characteristic and an actual output characteristic.

[Explanation of symbols]

 Reference Signs List 1 sensing device 3 central processing unit 10 detection unit 11 A / D converter 12 interface 15 storage unit 16 interface 17 transmission unit 20 memory rewriting device 21 CPU body 22 ROM 23 RAM

Claims (2)

(57) [Claims] A detecting means for detecting a predetermined physical quantity and outputting a predetermined analog level signal; an A / D converting means for converting an analog level signal from the detecting means into a digital signal and outputting the digital signal as a detection signal; A nonvolatile memory for holding output characteristic designation information for designating a predetermined output characteristic and correction information for correcting a detection signal from the A / D converter so as to follow the predetermined output characteristic in a readable / writable manner; The output characteristic designation information and the correction information held in the non-volatile memory are read from the non-volatile memory, and the detection signal from the A / D conversion unit follows the predetermined output characteristic based on the output characteristic designation information and the correction information. And a transmission means for sending the detected signal corrected by the central processing means to the outside .
The non-volatile memory complements the output characteristic designation information.
A sensing device characterized in that any of the positive information can be rewritten at any time . 2. A method for detecting a predetermined physical quantity and detecting a predetermined analog level.
In a sensing device that outputs a bell signal, the sensing device
Is a nonvolatile memory that holds predetermined information in a readable / writable manner.
Memory is provided, and the non-volatile memory includes
Reference output which is the correct output characteristic of the sensing device in advance
The characteristic slope a and offset b are used as output characteristic information.
And the actual output signal y2 of the sensing device
It is used as correction information for correcting to follow the reference output characteristics.
The slope c and offset d of the actual output characteristic and
Positive values (ac) and (bd) are written
And when the actual output signal y2 is output from the sensing device
Indicates output characteristic information of the sensing device from the nonvolatile memory.
Reports a, b and correction information c, d, (ac), (b-
d) and read the actual output signal y2 of the sensing device.
Y3 = (ac) (y2-d) / c +
(B-d), the actual output signal from the sensing device
An output value y = y2 + y3 obtained by correcting y2 with a correction amount y3 is obtained as
Output as the final output signal of the sensing device, and if the situation at the site where the sensing device is set changes.
When it is necessary to change the reference output characteristics ,
Output characteristic information a and b held in the non-volatile memory
Rewriting, or when the situation of the sensing device itself changes
Includes correction information stored in the nonvolatile memory.
c, d, that can exchange write (a-c), (b -d) Japanese
The method of correcting the output of the sensing device.