Data processing: generic control systems or specific application – Specific application – apparatus or process – Chemical process control or monitoring system
Reexamination Certificate
1998-06-30
2002-08-06
Shalwala, Bipin (Department: 2673)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Chemical process control or monitoring system
C700S278000
Reexamination Certificate
active
06430477
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a control apparatus for a gas analyzer system applicable, for example, to an automobile exhaust gas analyzer and a control method thereof.
DESCRIPTION OF THE PRIOR ART
In general, a gas analyzer system such as an automobile exhaust gas analyzer is required to be composed of a plurality of gas analyzers to measure various kinds of gases such as CO, CO
2
, THC, and NO
x
. The gas analyzers include a nondispersive infrared analyzer (hereinafter to be referred to as NDIR), a flame ionization detector (hereinafter to be referred to as FID), chemi-luminescent detector (hereinafter to be referred to as CLD), etc. Thus, multi-component gases to be measured such as automobile exhaust gas have so far been analyzed by a gas analyzer system comprising a plurality of gas analyzers for analyzing the specific gases and the gas analyzer processors connected to those gas analyzers.
FIG. 2
is a block diagram to show the control apparatus for the conventional gas analyzer system
20
. In
FIG. 2
, the gas analyzer system
20
comprises an analyzer processor
21
, analyzers
22
-
24
for analyzing respectively different specified gases, and cables
25
for connecting the respective parts
21
-
24
.
The analyzers
22
-
24
respectively have analyzer substrates
26
-
28
and analyzers
30
-
32
, and the respective analyzer substrates
26
-
28
are provided with CPUs
26
a
-
28
a
and non-volatile memories in which the programs for operating the CPUs
26
a
-
28
a
are written (hereinafter to be referred to as ROM)
26
b
-
28
b
. In other words, in this gas analyzer system
20
, due to the provision of the CPUs
26
a
-
28
a
on the respective analyzers
22
-
24
, individual controls of the analyzers
30
=
32
are made by these CPUs
26
a
-
28
a
. By mediating the inputted measuring signals through the communication part
29
and the cables
25
, the signals are transmitted to the analyzer processor
21
.
On the other hand, the analyzer processor
21
is provided with the CPU
21
a
and the ROM
21
b
, in which the program for operating the CPU
21
a
is written, so that it is possible to calculate the concentration value of various kinds of gases by processing the measuring signals inputted through the communication part
29
, and to display the results on the screen
21
d
or the like by outputting the results to the display processor
21
c
or the like.
Because the constitutions of the respective analyzers
30
-
32
are respectively different, the above analyzer substrates
26
-
28
are provided with the AD converters
26
c
-
26
g
,
27
c
,
27
d
,
28
c
-
28
f
for inputting the analog signals outputted from various gas analyzers A of the respective analyzers
30
-
32
and sensors S. The AD converters
26
c
,
26
d
,
27
c
,
28
c
,
28
d
are each an AD converter having one analog input port, making it possible to input the analyzing results from the gas analyzer A at a high speed. On the other hand, the AD converters
26
f
,
26
g
,
27
d
,
28
e
each has a multiplexer for changing over the four analog input ports, to which the measured values are inputted at a relatively low speed from the sensors for determining the sample flow amount, change in source voltage, temperature, etc. In the AD converter
26
e
or
28
c
which is provided with two or three analog input ports, the measured values are inputted at an intermediate speed.
Furthermore, the AD converters
26
c
-
26
g
,
27
c
,
27
d
,
28
c
-
28
f
self-contain respectively an amplifier for gain adjustment, being so constituted as to convert the measured values inputted from the analyzers
30
-
32
appropriately to digital signals.
Accordingly, the CPUs
26
a
-
28
a
are to carry out individually the gain adjustments of these AD converters
26
c
-
26
g
,
27
c
,
27
d
,
28
c
-
28
f
and control of the input speed of the measured values in conformity with the number and characteristics of the gas analyzers A and various sensors S in the analyzer units
30
-
32
.
The gas analyzer system
20
as described above controls the analyzer units
30
-
32
in the unit of the analyzers
22
-
24
, so that it describes the hardware information inherent to the analyzers
22
-
24
as the programs for the individual CPUs
26
a
-
28
a
. Accordingly, it has been necessary to compose programs for the individual analyzers
22
-
24
to give different operation commands to the respective CPUs
26
a
-
28
a
, write these programs in the ROMs
26
b
-
28
b
, and set them to the analyzer substrates
26
-
28
. For this purpose, when a new type of apparatus having the analyzer units
30
-
32
having different number of sensors and performance is manufactured, the number and performance of the AD converter are required to be changed, for which it becomes necessary to redesign the whole analyzer substrates
26
-
28
or newly recompose the program for the CPUs
26
a
-
28
a
, requiring a great deal of time and labor.
Above all, in the case of making a version of the gas analyzer system
20
which is already in use by the customers, when a change has been made in the number of the input signals from the analyzer unit or characteristics due to the improvement of the analyzer units
30
-
32
, it requires time for the work of rewriting the programs written on the ROMs
26
b
-
28
b
, and the version-up work is laborious.
In view of the above, it can be considered to make programming in a manner to make direct control of the analyzers
30
-
32
and AD converters
26
c
-
26
g
,
27
c
,
27
d
,
28
c
-
28
f
in CPU
21
a
in the analysis processing unit
21
and to write the program in the ROM
21
b
. However, when there are provided plural programs for controlling plural analyzers
22
-
24
in one CPU
21
a
, inversely it becomes necessary to modify the whole program for the sole purpose of changing the control method of one analyzer. In addition, because the control programs for the analyzers
30
-
32
include many common portions, to change only a part of the programs for making the similar processings tends to induce the generation of erroneous programming, leading to a danger of changing the control programs of other analyzers which need not be changed, thus making the controls more complicated.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the matters described above. Its objects, are to provide a control apparatus for the gas analyzer system for controlling a plurality of analyzers having different hardware constitutions in a single program which works on a single CPU, and a method for its control.
To attain the above objects, the control apparatus for the gas analyzer system of the present invention is characterized in that, in a gas analyzer system comprising a plurality of gas analyzers having gas analyzer units for analyzing respectively specified gases and an analyzer processing unit connected to these gas analyzers, the analyzer processing unit is provided with a CPU which is connected with each gas analyzer by a CPU bus and designed to control each gas analyzer. Each gas analyzer is provided with a plurality of AD converters having respectively a plurality of analog input ports in which the respective output signals of the gas analyzer units are inputted, and a non-volatile memory unit for storing the connection condition table which shows the connection condition of the gas analyzer unit to these AD converters. By connecting to the CPU bus, the CPU in the analyzer processing unit can control the respective gas analyzers by a single program.
The control method of the gas analyzer system of the present invention is characterized in that, in a gas analyzer system comprising a plurality of gas analyzers having gas analyzer units for analyzing respectively specified gases and an analyzer processing unit connected to these gas analyzers, and being provided with a plurality of AD converters having respectively plural analog input ports in each gas analyzer and a non-volatile memory unit irrespective of the kind of the gas analyzer, a table of connection conditions to show
Asami Tetsuji
Nishimoto Akihiro
Horiba Ltd.
Oppenheimer Wolff & Donnelly LLP
Patel Nitin
Shalwala Bipin
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