Plant monitoring system

A plant monitoring system having a memory unit for storing process variables and relationship data between main monitor screens and sub-monitor screens, a display unit including a main display area, an auxiliary display area, a main monitor screen selection area, a sub-monitor screen selection area and an alarm occurrence display area, and a control unit for controlling the whole system. By requesting from the main monitor screen selection area, a main monitor screen is usually displayed in the main display area, and one of the related sub-monitor screens is displayed in the sub-monitor screen area upon an operator's request from the already displayed sub-monitor screen selection area. When an alarm occurs, an alarm screen is displayed in the main displayed area.

BACKGROUND OF THE INVENTION 
This invention relates to a plant monitoring system for displaying a 
process variable of a plant as a pictorial image on a display unit to 
thereby supervise or monitor the process variable. 
For example, in a power generation plant, monitoring controls using a CRT 
display unit are widely adopted with the view of reducing the load on an 
operator and/or for improvement in the monitoring efficiency. For the 
content to be monitored, importance is attached to the monitoring of an 
operating process where the plant is in an unstable state, e.g., from 
startup of the power generation plant to ordinary operation thereof and/or 
from ordinary operation to shutdown of generation. Accordingly, there are 
provided many monitor screens for the unit of events or unit of systems 
adapted to the operating process. Such a monitoring system is exclusively 
directed to support of an operator with a view to stably operating the 
plant. In the event that any abnormal condition occurs, the investigation 
of the cause is ordinarily conducted by analyzing data such as plant data, 
afterwards. It is the present state of the art that detailed supervision 
up to such a level to investigate the cause on-line simultaneously with 
supervisory control of the operation cannot be carried out. Particularly, 
in a thermal power plant, as the profile of the power demand changes, 
plants in which daily startup and shutdown (DSS) use must be conducted for 
adjustment of the difference between power consumptions in the daytime and 
at night are increasing. In such plants, the states where plants become 
most unstable, such as startup and shutdown must be frequently repeated. 
Thus, more careful supervision than ever before becomes necessary. Such 
more careful supervision implies the feasibility of supervision having 
adaptability, or supervision capable of supporting abnormal cause 
diagnosis in an abnormal condition. To realize this, it is required to 
analyze one object to be supervised or monitored from every point of view, 
to conduct supervision while comparing individual objects to be 
supervised. Thus, the contents set for the monitor screen would increase 
and reach detailed levels. 
The improvement in the ability of computers makes it possible to 
immediately analyze a great deal of data and to cope with an increase in 
the volume of data handled. However, unless an operator can effectively 
use such information, it will be dead or ineffective information. 
According as more careful supervision is required to a great extent, 
analysis of data becomes indispensable. In some cases, professional 
knowledge at the analytical level also becomes necessary. It is predicted 
that such supervision using analytical data will be increasingly needed in 
future. For effectively using such data on-line by an operator in the same 
manner as in conventional supervision, how such data is to be presented is 
a problem. Namely, data which is abundunt and of detailed levels cannot be 
effective information until an operator comprehends it and handles it in 
conformity with the operation of the plant. 
SUMMARY OF THE INVENTION 
An object of this invention is to provide a plant monitoring system capable 
of supplying sufficient effective information to an operator. 
This object and other objects are accomplished by the plant monitoring 
system described below. Main monitor screens capable of roughly grasping 
or recognizing the entirety of items to be monitored determined in advance 
from the view point of supervision of a plant are provided. In addition, 
submonitor screens capable of grasping or recognizing the contents of the 
main monitor screens in correspondence therewith are provided. A storage 
unit for memorizing information for these monitor screens in advance is 
provided. There is provided a display unit for displaying pictorial images 
of these monitor screens on divided display areas thereof and a pictorial 
image of a command section interactive with an operator. An input unit 
where an operator designates the pictorial image of the command section 
displayed on the display unit is provided. In addition, there is provided 
means for displaying information related to screens for supervising or 
monitoring process variables when a main process variable of the plant is 
placed in an alarm state. 
When an operator displays a pictorial image of a plant monitoring system on 
the basis of picture information thereof memorized in the storage unit, he 
designates the pictorial image of the command section displayed on the 
display unit to conduit that display on a predetermined display area. When 
an alarm is produced, identification of the alarm screen and/or 
re-checking of the alarm screen identified are/is also conducted by 
designating the pictorial image of the command section using the input 
unit. 
Thus, an operator can supervise or monitor the plant based on the selection 
of an arbitrary monitor screen and the operation by an operator can be 
made through the input unit with the display unit being used as the main 
tool. Further, since the display area is divided, there are much 
information contents which can be displayed on a single cathode ray tube 
(CRT) and the processing when an alarm is generated can be suitably 
executed. Furthermore, the selection of monitor screens is entirely made 
by designating predetermined positions on the tube without switching to a 
menu screen, whereby a screen to be watched or information to be obtained 
can be called by one-touch operation. 
The monitor screen system employed in this invention is constructed in 
consideration of correlations between process variables to be supervised, 
thereby making it possible to provide information for monitoring means or 
groups of monitor screens to be closely watched by an operator. This 
increases the opportunity for early discovery of the cause of an abnormal 
condition. Further, one display unit is divided into a plurality of areas 
as stated above and thus all requests given by an operator can be visually 
satisfied on the screen of the display tube. Accordingly, the plant 
supervising equipment of this invention operates so that continuous 
supervision is realized in consideration of the coexistence of information 
automatically output from the system and a command based on a request from 
an operator, thus allowing for improvement in supervision efficiency. 
A preferred embodiment of this invention will be described with reference 
to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
An embodiment of this invention will be described with reference to the 
attached drawings. FIG. 1 is a block diagram showing a plant monitoring 
system according to this invention. The plant monitoring system of the 
invention comprises a computer system. 
Process variables from a plant 11 are scanned by process variable input 
means 12 and are then stored as process data in a storage unit 13. The 
storage unit 13 stores process data which has been read through the 
process variable input means 12 and also stores screen data for displaying 
the process data. Namely, the storage unit 13 stores data for a plurality 
of monitor screens displayed on a display unit 14 and also stores data 
indicative of correlations between a plurality of monitor screens (images 
of the monitoring system). 
FIG. 2 is an explanatory view showing the correlations between monitor 
screens (images of the monitoring system) wherein monitor screens related 
to a specified main screen (which will be referred to as a "main monitor 
screen" hereinafter) are grouped with respect to the main monitor screen 
and such screens in a group will be called sub-monitor screens. The main 
monitor screens are provided for every item to be monitored in the plant 
and the sub-monitor screens display thereon detailed information of items 
to be monitored. Namely, A and B represent a main monitor screen and ai 
(i=1 to 5) and bj (j=1, 2) represent sub-monitor screens related to the 
respective main monitor screens. In this example, the sub-monitor screen 
a.sub.3 of the main monitor screen A also serves as the sub-monitor screen 
of the main monitor screen B. As shown in this example, it is not required 
that groups of sub-monitor screens corresponding to respective items to be 
monitored be mutually exclusive. This is because for instance, when any 
abnormal condition occurs in connection with the items to be monitored 
represented by the main monitor screen B, there are instances where the 
cause of the abnormal condition appears in the monitored content of the 
sub-monitor screen a.sub.3 giving detailed information of the monitored 
items represented by the main monitor screen A. 
As above, the main monitor screen is a monitor-screen which can roughly 
grasp the entirety of items to be monitored among the groups of monitor 
screens allocated every item to be monitored, and the sub-monitor screen 
is a monitor screen which displays the details of the content of the main 
monitor screen, provides information related thereto, or displays the same 
process variable from a different point of view by changing the parameter. 
The data concerning the relationships between mutual monitor screens are 
stored in the storage unit 13. 
Then, process variable judgement means 15 reads thereinto process variables 
to be supervised for each operation stage through the process variable 
input means 12 to judge whether or not it falls within a normal range. For 
a reference for this judgement, a value equivalent to an alarm level which 
corresponds to a limit value of an allowed range in operating the plant as 
a limit value in dependence upon a process variable is set in advance. 
When a process variable deviates from the limit value thus set, the 
process variable judgement means 15 informs the alarm item supervisory 
means 16 of the occurrence of an alarm together with a title for an input 
point of the process variable. In addition, also when the alarm is 
released, the judgement means 15 informs the alarm item supervisory means 
16 of the warning. 
The alarm item supervisory means 16 has two Tables to supervise the 
condition of an occurrence of an alarm. Namely, it has a registration 
Table 17 indicating that the occurrence of an alarm is unacknowledged and 
a registration Table 18 indicating that occurrence of an alarm has been 
already acknowledged. When information indicating occurrence of an alarm 
is received from the process variable judgement means 15, a screen number 
of a screen for monitoring that process variable where an alarm has 
occurred (which will be referred to as an "alarm screen" hereinafter) is 
first registered in the unacknowledged registration Table 17. Then, a 
request for display of the monitor screen of the screen number registered 
is sent to display processing means 19, to display the pictorial image of 
that monitor screen on the display unit 14. It is to be noted that when 
there are a plurality of alarm screens, a test to register and display 
them in the order of occurrence of alarms is conducted, which will be 
described later. 
When a pictorial image of a monitor screen for monitoring the process 
variable in which an alarm has occurred is displayed on the display unit 
14, an operator confirms that he has recognized that the process variable 
is in an alarm condition. Such an acknowledgement or confirmation is 
conducted using the input unit 20 provided in association with the display 
unit 14. Upon receiving this confirmation, it is transmitted to the alarm 
item supervisory means 16 through command receiving means 21. Thus, the 
alarm item supervisory means 16 deletes the screen number registered in 
the unacknowledged registration Table 17 to register that number in the 
acknowledged registration Table 18. Where there are a plurality of alarm 
screens, a pictorial image of the next alarm screen is displayed on the 
display unit 14. It is to be noted that where the alarm condition of the 
process variable is released, these screen numbers registered in the 
registration Tables 17 and 18 are both deleted. Namely, the unacknowledged 
registration Table 17 is a registration Table for an alarm screen which 
has not been yet identified by an operator and the acknowledged 
registration Table 18 is a registration Table for an alarm screen which 
has been already acknowledged by an operator but in which the alarm 
condition has not been yet released. 
Then, the command receiving means 21 receives acknowledgement of the alarm 
screen, as described above, and also receives, on the other hand, a screen 
select command (display request) by an operator through the input unit 20. 
Namely, the command receiving means 21 receives, through the input unit 
20, a command for displaying a pictorial image of a specified screen from 
among various kinds of monitor screens stored as picture information in 
the storage unit 13. Upon receiving this screen select command, the 
command receiving means 21 activates display request supervisory means 22 
to take out necessary data from the storage unit 13 in dependence upon the 
content of the command to display a pictorial image of a screen 
corresponding to the command from the operator on the display tube surface 
of the display unit 14 by means of display processing means 19. In this 
example, where the display request by the operator and the display request 
for an unacknowledged alarm screen by the above-mentioned alarm item 
supervisory means 16 compete with each other, the display of the alarm 
screen has priority over other requests. 
The elements 12, 15, 16, 17, 18, 19, 21 and 22 constitute a controller 10. 
FIG. 3 is an explanatory view when pictorial image of various monitor 
screens stored a picture information in the storage unit 13 are displayed 
on the display unit 14 by an operator. The display tube surface of the 
display unit 14 is divided into five areas: a main display area 23, an 
auxiliary display area 24, a main monitor screen selection area 25, the 
sub-monitor screen selection area 26, and an alarm occurrence condition 
display area 27. 
The main display area 23 is an area for displaying a pictorial image of an 
alarm screen specified by the alarm item supervisory means 16 when a 
monitor screen requested by an operator or a process variable is brought 
into an alarm condition. This area is made up as the largest area on the 
display tube. 
The auxiliary display area 24 is an area for displaying at a reduced or 
contracted size a pictorial image of a monitor screen selected by an 
operator of pictorial images of the monitor screens displayed on the main 
display area 23. In addition, this area is also utilized for expanded 
display of the pictorial image of the monitor screen which has been 
contraction-displayed on the auxiliary display area 24, on the main 
display area 23 for a second time. This is carried out in response to a 
command from the input unit 20 by means of the display request supervisory 
means 22 and the display processing means 19. 
The main monitor screen select area 25 is an area on which labels for 
selecting main monitor screens representative of respective items to be 
monitored are displayed. A specified label is designated by the input unit 
20, whereby a pictorial image of a main monitor screen corresponding 
thereto is displayed on the main display area 23. 
The sub-monitor screen select area 26 is an area on which labels for 
selecting individual monitor screens of a group of screens in dependence 
upon that group of monitor items to be monitored displayed on the main 
display area 23 to which the monitor screen belongs are displayed. For 
example, assuming that discrimination labels of the main screens A and B, 
and sub-monitor screens ai (i=1 to 5) and bj (j=1, 2) are designated at 
L(A), L(B), L(ai) (i=1 to 5) and L(bj) (j=1, 2), respectively, where the 
pictorial image of the main screen A is displayed on the main display area 
23, L(A) and L(ai) (i=1 to 5) are displayed on the sub-monitor screen 
select area 26. In this condition, when a pictorial image of the main 
monitor screen B belonging to any other group of monitor screens is then 
displayed, the content of the sub-monitor screen select area 26 is 
switched. Thus, L(B) and L(bj) (j=1, 2) are displayed. A specified level 
of respective labels displayed on the sub-monitor screen select area 26 is 
designated by the input unit 20, whereby a pictorial image of a 
corresponding monitor screen is displayed on the main display area 23. 
The alarm occurrence condition display area 27 is an area for informing an 
operation about an alarm occurrence condition. When an indication label of 
an alarm (which will be called "ANN" hereinafter) is set in the display 
area 27 and a pictorial image of the alarm screen is automatically 
displayed on the display area 23 by the alarm item monitor means 16 at the 
time of occurrence of an alarm, this indication label ANN is blinked to 
draw an operator's attention, thus to urge acknowledgement. By allowing an 
operator to designate the indication label using the input unit 20, the 
alarm screen is controlled so as to become in conformity with the 
conditions blinking, turning-on, and turning-off which are presently 
displayed on the main display area 23. Namely, where there is any alarm 
screen which has not been yet acknowledged by an operator, a blinking 
display is conducted. Where all alarm screens are acknowledged, but there 
is any alarm screen in which the alarm condition is not released, a 
display with a light is turned on is provided. In addition, where there is 
no alarm screen placed in an alarm condition, a display with a light is 
turned off is provided. 
As just described above, various commands or instructions from an operator 
are realized using the input unit 20 on the basis of respective areas 23 
to 27 displayed on the tube surface of the display unit 14. The display 
request for the monitor screen is received or accepted by the command 
receiving means 21 by designating a label discriminating the main monitor 
screen within the main monitor screen select area 25 using the input unit 
20. Thus, picture information of the main monitor screen is taken out in 
correspondence with that label from the storage unit by the display 
request supervisory means 22 and is then displayed on the main display 
area 23 of the display unit 14 through the display processing means 19. 
Simultaneously, discrimination labels of all the monitor screens 
constituting a group of monitor screens to which that main monitor belongs 
are displayed by the display processing means 19. By allowing the input 
unit 20 to designate a specified label of the discrimination labels 
displayed, a pictorial image of a corresponding monitor screen is 
displayed on the main display area 23 in the same manner as in the case of 
the main monitor screen. Every time the main monitor screen displayed on 
the main display area 23 is switched, the sub-monitor screen select area 
26 is switched so that a monitor screen constituting a group of monitor 
screens corresponding to an item to be monitored which is represented by 
the main monitor screen can be selected. Such switching is carried out by 
the display processing means 19. Accordingly, once a main monitor screen 
is selected on the main monitor screen select area 25, i.e., if the item 
to be monitored is recognized, reference to the monitor screen for that 
item to be monitored can be designated by the sub-monitor screen select 
area 26. 
How the monitor screen is displayed on the display tube by an operator will 
be now described wherein main monitor screens representative of different 
items to be monitored are represented by A and B the sub-monitor screens 
are represented by ai (i=1 to 5) and bj (j=1, 2), and discrimination 
labels of respective screens are represented by L(A), L(B), L(ai) and 
L(bj), respectively. 
When L(A) is first designated within the main monitor screen select area 25 
by the input unit 20, a main monitor screen A corresponding thereto is 
displayed in the main display area 23 (CASE I in FIG. 3). At this time, 
L(A) and L(ai) (i=1 to 5) are displayed on the sub-monitor screen select 
area 26. When L(a.sub.2) is then designated within the sub-monitor screen 
select area 26 using the input unit 20, a pictorial image of the 
sub-monitor screen a.sub.2 corresponding thereto is displayed on the main 
display area 23, and the pictorial image of the main monitor screen A 
which has been displayed on the main display area 23 until now is 
displayed at reduced size in the auxiliary display area 24 (CASE II in 
FIG. 3). Further, when L(a.sub.4) is designated within the sub-monitor 
screen select area 26 by the input unit 20, a pictorial image of the 
sub-monitor screen corresponding thereto is displayed in the main display 
area 23, and the pictorial image of the sub-monitor screen a.sub.2 which 
has been displayed on the main display area 23 until now is displayed at 
reduced size in the auxiliary display area 24. Thus, the pictorial image 
of the main monitor screen A which has been displayed in the auxiliary 
display area 24 is deleted from the display tube (CASE III in FIG. 3). 
Then, when it is assumed that L(B) is designated by the input unit 20 
within the main monitor screen select area 25 for switching to a new item, 
to be monitored, the pictorial image of the main monitor screen B 
corresponding thereto is displayed in the main display area 23. Thus, 
L(B), L(a.sub.3) and L(bj) (j=1, 2) are instead displayed on the 
sub-monitor screen select area 26. Further, the pictorial image of the 
sub-monitor screen a.sub.4 which has been displayed on the main display 
area 23 is displayed at reduced size in the auxiliary display area 24, and 
the pictorial image of the sub-monitor screen a.sub.2 which has been 
displayed in the auxiliary display area 25 until now is deleted from the 
tube surface (CASE IV in FIG. 3). In addition, when the auxiliary display 
area 24 is designated by the input unit 20 for displaying in an enlarged 
size the pictorial image of the screen a.sub.4 having been displayed on 
the auxiliary display area 24 on the main display area 23 for a second 
time, the pictorial image of the screen a.sub.4 is displayed at an 
enlarged scale in the main display area 23, and the pictorial image of the 
main monitor screen B which has been displayed in the main display area 23 
until now is instead displayed in the auxiliary display area 24 at reduced 
size. At this time, since the sub-monitor screen a.sub.4 belongs to a 
group of monitor screens different from the main monitor screen B, L(A) 
and L(ai) (i=1 to 5) will be instead displayed in the sub-monitor screen 
select area 26 (CASE V in FIG. 3). 
How display on the tube surface is conducted when an alarm has occurred 
will be now explained. It is now assumed that screens monitoring process 
variables x and y are represented by x and y and alarm screens, when the 
process variables x and y reach the alarm condition, are represented by 
X.sub.ANN and Y.sub.ANN, respectively. The screens X and Y may be either a 
main monitor screen or a sub-monitor screen. At this time, it is further 
assumed that the pictorial image of the sub-monitor screen a.sub.2 has 
been displayed in the main display area 23 and the pictorial image of the 
main monitor screen A has been in the auxiliary display area 24. In this 
condition, if the process variable x is brought into an alarm condition, 
since the display request for the monitor screen by an operator has higher 
priority than the display request for the alarm screen, the pictorial 
image of the alarm screen X.sub.ANN is automatically displayed in the main 
display area 23 by the alarm item supervisory means 16. Further, for the 
purpose of allowing an operator to quickly identify the alarm screen, the 
indication label ANN within the alarm occurrence condition display area 27 
blinks. The pictorial image of the sub-monitor screen a.sub.2 which has 
been displayed in the main display area 23 is reduced to the dimension of 
the auxiliary display area 24, and the pictorial image of the main monitor 
screen A which has been displayed in the auxiliary display area 24 is 
deleted from the display tube surface (CASE I in FIG. 4). In, the 
sub-monitor screen select area 26, a discrimination label for a group of 
monitor screens to which the alarm screen X.sub.ANN belongs is displayed. 
At this stage, the operator designates the blinking indication label using 
the input unit 20, thereby to send a command that the alarm screen has 
been acknowledged to the alarm item supervisory means 16 through the 
command receiving means 21. Unless such an acknowledgement is conducted, 
it is impossible to display other monitor screens in the main display area 
23. Namely, the pictorial image of the alarm screen concerned is 
continually displayed. 
After identification, as long as there is no alarm screen which has not 
been acknowledged at that time and the alarm condition is not released, 
the display by the indication label ANN is switched to such a display as 
to turn on a light (CASE II in FIG. 4). Thus, the pictorial image of other 
monitor screens based on the display request by an operator may be 
displayed. On the other hand, if a process variable y, different from the 
process variable x, is in an alarm condition at the time when 
acknowledgement is made, the pictorial image of the alarm screen Y.sub.ANN 
is automatically displayed in the display area 23 by the alarm item 
supervisory means 16 with the indication label ANN blinking. The pictorial 
image of the alarm screen Y.sub.ANN is displayed in the main display area 
23 in the same manner as in the case of the monitor screen requested by 
the operator. However, where the pictorial image of the screen which has 
been displayed in the main display area until now is that of the alarm 
screen, the pictorial image of that alarm screen is not displayed at 
reduced size in the auxiliary display area 24. Accordingly, the pictorial 
image of the alarm screen X.sub.ANN which has been displayed in the main 
display area 23 is deleted from the display tube surface (CASE III in FIG. 
4). In this case, it is needless to say that the discrimination label for 
the group of monitor screens to which the alarm screen Y.sub.ANN belongs 
is displayed in the sub-monitor screen select area 26. There is no 
possibility that the pictorial image which has been displayed once as an 
alarm screen and acknowledged by an operator is automatically displayed as 
long as that warning condition is released and an alarm condition is not 
newly established. 
The processing of the display request by an operator and the display 
processing when an alarm has occurred may be accomplished by the input 
unit 20, the command receiving means 21, the alarm item supervisory means 
16, the display request supervisory means 22, and the display processing 
means 19. An explanation will be made in connection with these 
processings. 
The input unit 20 serves to designate through the tube surface of the 
display unit 14 the positions of various command sections displayed on the 
tube surface thereof. The display position of the command section 
specified by such a designation is delivered to the command receiving 
means 21 within the computer, thereby making a display request. For the 
input unit 20, there are touch panel, track ball, keyboard and mouse, etc. 
inputs and any one of them may be used. 
The command receiving means 21 inputs a positional signal on the tube 
surface output from the input unit 20 to interpret the command section 
displayed thereon to interpret thereby the content of the command by an 
operator. Such an interpretation is made with the command section being 
classified into sections of fixed contents and sections of variable 
contents depending upon the monitor screen. Namely, for a command in the 
case of shifting a display from the auxiliary display area 24 to the main 
display area 23, the display position of the label of the auxiliary 
display area 24 is a section for command. Such a command section is a 
fixed command section which does not vary even if the monitor screen 
displayed changes. Also, the discrimination label displayed in the main 
monitor screen select area 25 is generally fixed because it is a command 
section for selecting items of the plant to be monitored, i.e., the main 
monitor screen. In addition, the label ANN displayed on the warning 
occurrence condition display area 27 is generally fixed because it is a 
command value common to the warning screens. For indication labels such 
that the command section is fixed as stated above, the display position 
signal on the display tube surface and the command content thereof are 
stored in advance and correlated with each other, so that they can be 
interpreted. 
On the other hand, for indication labels varying depending upon the monitor 
screen displayed in the main display area 23 as in the discrimination 
label displayed on the sub-monitor screen select area 26, the content 
being displayed presently in the sub-monitor screen select area 26 is 
input by the display processing means 19 supervising what is displayed in 
any place on the tube surface, so that it is interpreted in combination 
with the position signal. 
In the case of the command related to the alarm screen, i.e., the command 
of the alarm occurrence condition display area 27 as a result of 
interpretation of the command from an operator, the alarm item supervisory 
means 16 is informed of the command content. In addition, in the case of 
the command related to the display request for the monitor screen, i.e., 
the command of the display areas 24, 25 and 26, the display request 
supervisory means 22 is informed of the command content. It is to be noted 
that since the command section is determined in advance for the display 
content, setting may be made according to need also within the main 
display area 23. 
The alarm item supervisory means 16 becomes operative in response to a 
command by an operator from the command receiving means 21 (a command from 
the alarm occurrence display area 27). For the processing to be conducted 
on the premise thereof, such processing is executed to display the 
pictorial image of the alarm screen in the main display area 23 to output 
to the display processing means 19 a command for carrying out a blinking 
display of the alarm indication label ANN in the alarm occurrence 
condition display area 27. Namely, when the alarm item supervisory means 
16 receives from the process variable judgement means 15 information of a 
process variable which has reached the alarm state, it registers the 
picture information of the screen monitoring that process variable into 
the unacknowledged registration Table 17 as the alarm screen, thus to 
output to the display processing means 19 a display request for that alarm 
screen and a blinking display request for the indication label ANN of the 
alarm occurrence condition display area 27. When the alarm item 
supervisory means 16 receives from the command receiving means 21 an alarm 
acknowledgement command from an operator, if the picture information of 
the screen number of the alarm screen is registered in the unacknowledged 
registration Table 17, it judges that the screen number registered earlier 
has been acknowledged, in order to cancel the registration of the 
unacknowledged registration Table 17 and to instead register it into the 
acknowledged registration Table 18. At the time when the unacknowledged 
registration Table 17 becomes empty, a request for turning on the display 
label ANN is output to the display processing means 19. On the other hand, 
where the alarm item supervisory means 16 receives information for 
releasing the warning condition from the process variable judgement means 
15, it begins cancellation of the corresponding warning screen from the 
registration of the acknowledged registration Table. At the time when both 
the unacknowledged registration Table 17 and the acknowledged registration 
Table 18 become vacant, a request for turning off the indication label ANN 
is outputted to the display processing means 19. 
Then, the display request supervisory means 22 receives display request 
commands of various monitor screens sent from the command receiving means 
21 to discriminate that display command. First, judgement is made whether 
or not that request is a request for displaying the pictorial image of the 
monitor screen displayed in the auxiliary display area 24 in the main 
display area 23 at an enlarged scale. As a result, if so, a request is 
made to the display processing means 19 to exchange the screen displayed 
in the main display area 23 and that in the auxiliary display area 24, In 
contrast, if not so, it is judged that a display request for a monitor 
screen is newly outputted thus making a judgement as to whether that 
display request is a display request of the main monitor screen from the 
main monitor screen select area 25 or a display request of a monitor 
screen from the sub-monitor screen select area 26. Where that display 
request is the command from the main monitor screen select area 25, a 
display request of the selected main monitor screen is outputted to the 
display processing means 19 and a group of monitor screens set as the 
sub-monitor screen of the main monitor screen is discriminated by the 
image information of the monitor system stored in the storage unit 13 to 
specify a label for discrimination of the monitor screen caused to be 
displayed in the sub-monitor screen select area 26, thus to output a 
display request therefor to the display processing means 19. In contrast, 
where that display request is the command from the sub-monitor screen 
select area 26, a display request for the selected monitor screen is 
outputted to the display processing means 19. 
The display processing means 19 receives various display requests from the 
alarm item supervisory means 16 and the display request supervisory means 
22 to execute display processing in order to satisfy these display 
requests. Namely, the display processing means 19 preferentially executes 
the display request from the alarm item supervisory means 16 when the 
command from alarm item supervisory means 16 and the command from the 
display request supervisory means 22 compete with each other, collects and 
prepares information to be displayed, effects layout of display position 
on the tube surface of the display unit 14, or the like. Namely, the 
storage unit 13 stores therein the definition as to what should be 
displayed for respective plural areas defined on the tube surface of the 
display unit 14, the definition and the like as to how to move the 
pictorial image on the tube surface, and holds at all times information as 
to what is being displayed in any portion on the tube surface at the 
present time. When the display processing means 19 receives a display 
request from the alarm item supervisory means 16 or the display request 
supervisory means 22, it collates the present display condition on the 
tube surface with the display request content, thus displaying on the 
display unit 14 the content which satisfies the display request in 
accordance with the above-mentioned definitions. 
FIG. 14 shows a construction of the display processing means 19. This means 
comprises a plurality of pictorial image holding means 191a-191n, 
plurality of multipliers 192a-192n which provide proper multiplication 
factors for the outputs of the pictorial image holding means 191a-191n, a 
layout control section 193 which arranges pictorial images to their 
desired position within the screen and a controller 194 which executes 
overall control for the elements within the display processing means 19. 
The pictorial image holding means receive and hold pictorial image data 
which are stored in the storage unit 13. In the storage unit 13, the 
pictorial data, which is composed of mainly character/image data, for each 
main/sub screen are allocated to some address. And these data are read out 
from the storage unit 13 using the readout program and are held in the 
pictorial image holding means as they are. The multipliers 192a-192n give 
proper multiplication factors to the pictorial image data according to 
dimensions of screen area allocated to the data. Then the layout control 
section gives addresses in the whole screen to the pictorial image data 
taking account of the multiplication factors. 
An explanation will be made in connection with the case where the plant 
monitoring system according to this invention is applied to the 
supervision of vibration of a turbine generator. In such an 
implementation, supervision of vibration is of course conducted using 
monitor screens. In this case, not only analysis of the vibration is made, 
but also support factors to pursue the cause of vibration are subject to 
supervision. Namely, since most abnormal conditions of the turbine appear 
as vibration when attention is drawn to the supervision of the turbine 
generator, the bearing vibration of the turbine is significant for the 
object to be superposed. Since the vibration is taken as a judgement basis 
when any abnormal condition occurs, analysis of the vibration itself is 
first required. For example, vibration first analyzed on-line with 
amplitude, phase and frequency which can be said to be three major 
elements of vibration that are parameters to determine items to be 
monitored so that changes in the analytical data can be monitored with the 
number of turbine revolutions and/or load being as parameters. Further, 
for information to support the pursuit of the cause of vibration, factors 
directly related to the turbine rotor such as at least a bearing feed oil 
temperature, a bearing metal temperature, a bearing return oil 
temperature, a differential expansion of the turbine, or thermal stress, 
etc. are set for the objects to be monitored, thus to determine items to 
monitored so that changes in the factors can be monitored. 
For items to be monitored for analyzing vibration, five items to be 
monitored are set: monitoring of vibration frequency, monitoring of 
vibration amplitude and phase angle, monitoring of vibration amplitude 
according to load changes, monitoring of vibration amplitude according to 
changes in rotational frequency, and rub check monitoring. In addition, 
for items to be monitored which support the pursuit of the vibration 
cause, five items to be monitored are set: monitoring of bearing metal 
temperature/bearing return oil temperature, monitoring of bearing feed oil 
temperature, monitoring of differential expansions, monitoring of thermal 
stress, and monitoring of vacuum elevation. For these ten items to be 
monitored, several sub-monitor screens are provided. 
For brevity of description, an explanation will be made by the example of 
monitoring of vibration amplitude according to changes in rotational 
frequency (which will be called vibration S-V hereinafter), and monitoring 
of bearing metal temperature/bearing return oil temperature (which will be 
called bearing monitor hereinafter). In this case, the configuration of 
the monitor system image of a group of monitor screens for the vibration 
S-V and the bearing monitor is assumed as shown in FIG. 5. As shown in 
FIG. 8 described later, the main monitor screen 28 for the vibration S-V 
is a monitor screen which displays three-dimensionally the vibration 
amplitude according to changes in rotational frequency from the first 
bearing up to the eighth bearing, thus to roughly grasp or recognize 
changes in the entire vibration amplitude. This main monitor screen is 
called the vibration S-V collective screen hereinafter. In order to effect 
mutual comparison between bearings or monitoring of individual bearings by 
using sub-monitor screens with respect to the main monitor screen, 
sub-monitor screens provided for arbitrarily selecting one bearing, two 
bearings and four bearings from these eight bearings to be monitored. 
These sub-monitor screens will be called the vibration S-V four bearing 
screen 29, the vibration S-V two bearing screen 30, and the vibration S-V 
one bearing screen 31 depending upon the number of bearings displayed 
within the same monitor screen. 
On the other hand, the main monitor screen 32 for the bearing monitor 
serves to monitor current values of the bearing metal temperature and the 
bearing return oil temperature from the first bearing up to the eighth 
bearing. This main monitor screen 32 is a monitor screen for grasping the 
present state of bearings at a glance. In order to monitor changes with a 
lapse of time for individual bearings, there are provided, for sub-monitor 
screens with respect to the main monitor screen 32, a bearing monitor time 
lapse screen 33 to select a single specified bearing to monitor changes 
with lapse of time of the bearing metal temperature and the bearing return 
oil temperature, a bearing metal time lapse screen 34 to select a single 
specified bearing to monitor changes with lapse of time of the bearing 
metal temperature, and a bearing return oil time lapse screen 35 to select 
a single specified bearing to individually monitor changes with lapse of 
time of the bearing return oil temperature. Further, an oil supply 
temperature time lapse screen 36 for monitoring changes with lapse of time 
of the bearing supply oil temperature closely related to the bearing metal 
temperature/the bearing return oil temperature is provided. In addition, 
when any abnormal condition is observed in the temperature condition, the 
vibration S-V two bearing screen 37 which is the vibration screen is set 
as the sub-monitor screen for the bearing monitor for monitoring 
vibration. 
FIG. 6 is an explanatory view showing the tube surface of the display unit 
14 when the pictorial image of the vibration S-V collective screen is 
displayed as the main monitor screen in the case supervising turbine 
vibration. In the main monitor screen select area 25 of the display unit 
14, the discrimination label 38 of the above-mentioned items to be 
monitored will be displayed. It is now assumed that the discrimination 
label 38b for the vibration S-V is selected. Thus, the pictorial image of 
the main monitor screen for the vibration S-V as shown in FIG. 8 is 
displayed in the main display area 23. A bearing select area 39 is 
provided in a portion of the main display area 23 as an interactive area, 
thus making it possible to select an arbitrary bearing from the first to 
the eighth bearings of the turbine rotor bearings. Namely, in the bearing 
select area 39, the pictorial image of a command section for specifying a 
bearing to be displayed on the vibration S-V four bearing screen 29, the 
vibration S-V two bearing screen 30, and the vibration S-V one bearing 
screen 31. Namely, as shown in FIG. 6, a frame diagram is displayed in the 
bearing select area 39 by the image for positioning of bearings and 
numeric values of 1 to 8 of the bearing number are set as a command 
section for selection of bearings. By designating the numeric portion 
using the input unit 20, a desired bearing is selected. 
In the sub-monitor screen select area 26, a command section for selecting 
the screen displayed in the main display area, i.e., a specified screen of 
a group of monitor screens of items to be monitored to which the vibration 
S-V collective screen 28 belongs is displayed as discrimination label 40. 
On the other hand, two command sections of alarm label 41 and alarm standby 
label 42 are displayed in the warning occurrence condition display area 
27, thus to supervise the occurrence condition of an alarm by a 
combination of blinking, turning on and turning off of the alarm label 41 
and turning on and turning off of the alarm standby label 42. 
How display is conducted in the case of supervision of the turbine 
vibration will be explained with reference to FIG. 7. First, when the 
discrimination label 38b for the vibration S-V of items to be monitored is 
designated in the main monitor screen select area 25 using the input unit 
20, the pictorial image of the vibration S-V collective screen 28 
corresponding thereto is displayed in the main display area 23. In 
addition, the vibration S-V collective 40a, the vibration S-V two bearings 
40c and the vibration S-V one bearing 40d which are discrimination labels 
for a group of monitor screens to which the item to be monitored belongs 
are displayed in the same diameter vibration S-V select area 26 (CASE I in 
FIG. 7). FIG. 8 shows an example of the display of the vibration S-V 
collective screen 28. It is seen from this figure that the behavior of 
amplitude of the first bearing to the eighth bearings can be roughly 
grasped. 
Then, when the label 40b of the vibration S-V four bearings of 
identification labels of the same system monitor screens is designated, 
the vibration S-V collective screen 28 which has been displayed in the 
main display area 23 until now is displayed at a reduced scale in the 
auxiliary display area 24. Then, the pictorial image of the screen 
displayed in the display area 23 is switched to the vibration S-V four 
bearing screen 29 which is a new monitor screen (CASE II in FIG. 7). The 
vibration S-V four bearing screen 29 is the monitor screen adapted so that 
four bearings requested by an operator among the first to the eighth 
bearings can be monitored on the same screen. When the discrimination 
label 40b of the vibration S-V four bearings is selected from the 
sub-monitor screen select area 26, an operator sets four bearings in the 
bearing select area 39 of the main display area 23 in accordance with the 
standard shown in FIG. 9 with the bearing having the largest amplitude 
being as a center among the first to the eighth bearings. 
In FIG. 9, double circular mark .circle. denotes the bearing with the 
largest amplitude. This figure shows that when it is seen that, e.g., the 
second bearing is the bearing with the maximum amplitude by the vibration 
S-V collective screen 28 (FIG. 8) which is the main monitor screen, the 
second bearing must be selected at first. Namely, when the vibration S-V 
one bearing screen 31 (discrimination label 40d) is selected as the 
sub-monitor screen, two bearings of the bearing (second bearing) labeled 
double circular mark .circle. for maximum amplitude and the bearing 
(first bearing) labeled with a triangular .DELTA. mark which has the 
greatest influence thereon are selected. When the vibration S-V four 
bearing screen 29 (discrimination label 40b) is selected as the 
sub-monitor screen the bearing (second bearing) labeled with a double 
circular mark .circle. for maximum amplitude, the bearing (first 
bearing) labeled with a triangular mark .DELTA. which has the greatest 
influence thereon, and bearings (third and fourth bearings) labeled with a 
circular mark .circle. which have smaller influence thereon are 
selected. 
Such a bearing select area 39 is not displayed at all times, but is 
displayed only when the monitor screen which can make a selection of every 
bearing as stated above is displayed. The above-mentioned display 
processing is conducted in accordance with the processing by the display 
processing means 19. 
How bearings are switched will be explained with reference to FIG. 10. It 
is now assumed that the vibration four bearings screen 31 is selected and 
four bearings, such as the first up to the fourth bearing, have been 
displayed. Such bearings are displayed on four divisional areas obtained 
from the main display area 23, respectively. In this condition, in the 
case of monitoring the behavior of the fifth and sixth bearings instead of 
the third and fourth bearings, the first step is to designate the bearing 
number 5 in the bearing select area 39 of the main display area 23, and 
thereafter designate where it is displayed in the main display area 23. 
Assuming now that the fifth bearing is displayed in place of the third 
bearing, the area on which the screen for the third bearing of the main 
display area 23 is designated by the input unit 20. Thus, data indicative 
of the fifth bearing is displayed on a portion where the third bearing has 
been displayed (CASE I in FIG. 10). Similarly, the bearing number 6 is 
designated in the bearing select area 39. Subsequently, when the bearing 
number 6 is designated in the display area 39 for the fourth bearing of 
the main display area 23 and the display area for the fourth bearing of 
the main display area 23 is designated, data indicative of the sixth 
bearing is displayed in place of the fourth bearing. Thus, data indicative 
of four bearings of the first, the second, the fifth and the sixth 
bearings are displayed on the screen (CASE II in FIG. 10). The selection 
of bearings is made by a two stage designation comprising selecting the 
number of a bearing to be monitored by the bearing select area 39 and 
designating where it is displayed in the main display area 23. 
This applies in the same way to monitor screens capable of selecting 
bearings. It is to be noted that since only data indicative of one bearing 
to be monitored in detail is displayed within the screen therefor, it is 
sufficient to select only the bearing number in the main display area 39. 
The above-mentioned function is accomplished by the input unit 20, the 
command receiving moans 21, the display request supervisory means 22, and 
the display processing means 19. 
Then, under conditions where the pictorial image of the vibration S-V four 
bearing screen 29 is displayed in the main display area 23 and the 
pictorial image of the vibration S-V collective screen 28 is displayed in 
the auxiliary display area 24, when the auxiliary display area 24 is 
designated by the input unit 20, the pictorial image of the vibration S-V 
collective screen 28 is displayed at an enlarged scale for a second time, 
and the pictorial image of the vibration S-V four bearing screen 29 which 
has been displayed until now is instead displayed at a reduced scale in 
the main display area 23. Simultaneously with this, the display of the 
bearing select area 39 disappears (CASE III in FIG. 7). 
Further, when the discrimination label 38a of the bearing monitor which is 
the item to be monitored is designated by the main monitor screen select 
area 25, the vibration S-V collective screen 28 which has been displayed 
in the main display area 23 is displayed at a reduced scale, and the 
vibration S-V four bearing screen 29 which has been displayed in the 
auxiliary display area 24 disappears from the display tube. Moreover, the 
bearing monitor screen 32 which is the corresponding main monitor is 
displayed in the main display area 23. In addition, the system screen 
select area 26 is also switched to the bearing sub-screen which is the 
item to be monitored. Thus, for the group of monitor screens belonging to 
that item to be monitored, indication labels indicative of the bearing 
monitor time lapse 43b, bearing metal time lapse 43c, bearing waste oil 
time lapse 43d, oil supply temperature time lapse, and vibration S-V two 
bearing are displayed (CASE IV in FIG. 7). 
When an alarm occurs, the alarm label 41 of the warning occurrence 
condition display area 27 blinks and thus the pictorial image of the alarm 
screen is displayed in the main display area 23. If the pictorial image of 
the screen which has been displayed until now corresponds to that 
displayed according to requirement by an operator, the pictorial image of 
that screen is displayed at a reduced scale on the auxiliary display area 
24. Since the alarm screen displayed in the main display area 23 is 
required to be identified for an operator, the designation of blinking 
alarm label 41 results in a command for identification. As long as 
identification is not conducted, requesting display of other monitor 
screens, or calling into the main display area 23 the monitor screen 
displayed on the auxiliary display area 24 cannot be accomplished. In 
addition, since a plurality of alarms may occur at a time, the alarm label 
41 is blinked and the alarm standby label 42 is turned on in such a case. 
An explanation will be made in connection with the case where a plurality 
of alarms have occurred at the same time with reference to FIG. 11. It is 
now assumed that three alarms have occurred at the same time and alarm 
screens corresponding thereto are represented by ANN1, ANN2 and ANN3. It 
is further assumed that the alarm screen according to an operator's 
request which was displayed before occurrence of the alarm is represented 
by S. First, the alarm label 41 blinks and the alarm standby label is 
turned on. In addition, ANN1 and S are displayed in the main display area 
23 and the auxiliary display area 24, respectively. When an operator 
identifies the blinking alarm occurrence to designate the alarm label 41, 
ANN1 is considered to be identified and ANN2 is then displayed in the main 
display area 23. Since ANN1 is not the screen according to an operator's 
request, there is no possibility that it is displayed in a reduced scale 
in the auxiliary display area 24 and therefore it is deleted from the 
display tube surface. At this time, the alarm label 41 and the alarm 
standby label 42 are in the same state as in the previous state (CASE I in 
FIG. 1). 
Further, when the blinking alarm label 41 is designated, ANN2 is considered 
to be acknowledged, so that ANN3 is instead displayed in the main display 
area 23. Simultaneously with this, since there is no alarm screen which is 
not displayed on the display tube surface at this time, the alarm standby 
label 42 is turned off (CASE II in FIG. 11). While the alarm label 41 
remains blinking, such a label is designated, whereby ANN3 is acknowledged 
and thus the alarm label 41 changes to the turn-on mode. It is needless to 
say that the above-mentioned processing at the time of occurrence of an 
alarm is accomplished by the input unit 20, the command receiving means 
21, the alarm items supervisory means 16, and the display processing means 
19. 
At the time when the alarm label 41 has finished blinking, a request from 
an operator through the display request supervisory means 22 can be 
received. The turning-on of the alarm label 41 shows that there exists a 
screen which has been acknowledged by an operator, but from which the 
alarm state has not been yet released. In the case of taking out only 
these alarm screens, when blinking alarm labels 41 are designated, these 
alarm screens are cyclically displayed in the main display area 23 for 
every designation. This is realized by utilizing the acknowledged 
registration Table 18 in which picture information of alarm screens which 
have been acknowledged by an operator, but from which the alarm state has 
not been released are registered, thus outputting pictorial images of 
screens in order of picture information registered therein. 
The content of information of the alarm occurrence condition for an 
operator is based on the combination of blinking, turning-on and 
turning-off of the alarm label 41 and turning-on and turning-off of the 
alarm standby label 42 is shown in FIG. 12. 
In this example, calling of the identified alarm screen into the main 
display area 23 by designating the alarm label 41 turning on can be said 
to be displaying of a screen according to an operator's request, and here 
is employed an arrangement such that the alarm screen is not displayed 
once at a reduced scale in the main display area 24 for clarifying the 
operation of the system. It is to be noted that screens, which are 
selected by an operator by utilizing the main monitor screen select area 
25 or the sub-monitor screen select area 26 and then displayed in the main 
display area 23 even if they are the same screen, may be displayed once at 
a reduced scale in the auxiliary display area 24. 
Setting of alarm screens will be made as follows. For instance, where a 
limit value of an alarm is provided in the vibration S-V and thus this is 
assumed as the item to be monitored, if all the screens monitoring that 
process variable are simply considered to be alarm screens, the vibration 
S-V collective screen and the vibration S-V N bearing screen (N=1, 2, 4) 
are all subject to the alarm screen for the vibration S-V. However, this 
only allows an operator to be troublesome. When the characteristic of the 
vibration is taken into consideration, it is seen that there is employed a 
structure such that the first and second bearings, the third and fourth 
bearings, the fifth and sixth bearings, and the seventh and eighth 
bearings are affected by each other, respectively. Accordingly, where one 
bearing reaches the alarm range, it is effective to display two bearings, 
i.e., that bearing and a bearing paired therewith. Thus, such a case is 
supervised by the vibration S-V two bearing as the alarm screen. Since 
there are several instances where one object to be monitored, i.e., 
process variable is monitored by many screens as stated above, also in the 
case of setting the alarm screen, one optimum monitor screen is selected 
to be used as a screen for signaling an alarm by taking into account the 
characteristic of the process variable placed in the alarm state. In 
addition, also where the alarm screen is displayed in the main display 
area 23, the title of the monitor screen for items to be monitored to 
which the alarm screen belongs is displayed in the sub-monitor screen 
select area 26 in the same manner as stated above. Accordingly, after 
acknowledgement of the alarm screen is conducted, it is possible to 
designate the sub-screen select area to switch the screen, thus to monitor 
the cause of that alarm, influence on others, or the like. As previously 
described, by systematization of the main and sub-monitor screens every 
item to be monitored exhibits a great effect in this embodiment. The alarm 
screen which signals a process variable which has reached an alarm value 
is first automatically displayed in the main display area to which the 
operator pays attention. Thus, information answering "what is the cause . 
. . ?" is presented. 
While the relationships between the main monitor screens and the 
sub-monitor screens, i.e., the supervisory system images are stored in 
advance every item to be monitored in the above-mentioned embodiment, a 
discrimination label of, e.g. all screen lists may be provided in the main 
monitor screen select area 25 to select this to thereby display, as a 
list, discrimination labels of a group of monitor screens for every item 
to be monitored as shown in FIG. 13, thus to make an alteration to the 
monitor system image. To realize this, command sections for a deletion 
label 45 and a registration label 46 are set in the bearing select area 39 
and then displayed thereon, thus to effect rearrangement and/or deletion 
of monitor screens within the screen for displaying all screens as a list. 
Namely, in the case of effecting deletion, there is employed a method to 
designate the deletion label 45, thereafter to designate the 
discrimination label for a monitor screen needed to be deleted. Further, 
in the case of registering a sub-monitor screen defined as an item to be 
monitored into another item to be monitored, there is employed a method to 
designate the registration label 46 to designate a discrimination label of 
a sub-monitor screen needed to be registered to further designate a 
discrimination label of the item to be monitored, into which that 
sub-monitor screen is registered. By freely or desirably combining groups 
of monitor screens with each other, the optimum monitor system can be 
constructed for use in conformity with the actual plant operation. Also, 
it is needless to say that where there is a need to additionally register 
a completely new monitor screen, this is carried out after data indicative 
of that monitor screen is stored in the storage unit 13. 
Since it has been an object to carefully carry out the supervision of the 
turbine vibration in the above-mentioned explanation, analysis thereof has 
been made using three parameters, i.e., frequency, phase and amplitude for 
the vibration taken as an example, so that the detailed supervision may be 
conducted. Accordingly, where any abnormal condition, occurs, this 
supervising or monitoring system can grasp a sign of the abnormal 
condition before the process variable reaches a limit value set in the 
prior art. In addition, there may be employed a method to accumulate 
achievement data and to set a cautionary value to draw the attention of an 
operator before the alarm state is reached, thus to automatically display 
that cautionary screen from the system when the analytical data enters 
into the cautionary value. In this case, an area for display of the 
cautionary screen is exclusively provided on the tube surface. From the 
viewpoint of an early discovery of an abnormal condition, importance is 
attached more to caution than alarm, thus to conduct only necessary and 
minimum handling as the alarm screen and to set cautionary values based on 
the achievement data of the analytical level, whereby the degree of 
support for an operator is increased and the accuracy of supervision is 
further improved. 
As described above in detail, the monitor screen system according to this 
invention is constructed in consideration of correlations between process 
variables to be supervised, thereby making it possible to provide 
information of monitoring means or groups of monitor screens to be closely 
watched by an operator. This exhibits an increased opportunity for early 
discovery of the cause of an abnormal condition. Further, one display unit 
is divided into a plurality of areas and thus all requests given by an 
operator can be visually satisfied on the screen of the display tube. 
Accordingly, the plant supervising equipment of this invention has such 
improved operation that continuous supervision is realized in 
consideration of the coexistence of information automatically output from 
the system and a command based on a request from an operator, thus 
providing an improvement in the supervision efficiency, particularly, 
since a command section for receiving an operator's request without 
setting a menu screen is set on the display tube, information that an 
operator desires to obtain can be readily displayed.