XY Plot - ABB Solution Bank

XY Plot - ABB Solution Bank
XY Plot Operations
Section 15
Introduction
The XY plot function can be used to plot pairs of process variables in an x,y graph format for process analysis. The x-axis is
determined by one process variable, the y-axis another.
Three types of plots can be created. The data source defined for
a plot determines whether the data is exception reported tag
values (tag source), distributed trend data (trend source), or
values collected by a program running in a control module
(except MFC module). The data source for a plot is selected
during XY plot definition. Up to 80 indexed plots can be
defined.
Tag or Trend XY Plot
The variables that appear in a tag or trend type of XY plot
depend on the plot definition used in the display. Each plot
definition defines the data for a single plot. The characteristics
of a tag or trend plot are set up during plot definition. Specifically, plot definition identifies:
•
•
•
•
•
•
•
•
Data source (tag data or trend data).
Initial update mode.
X-axis variable.
Y-axis variable.
Initial x-axis and y-axis high and low limits.
Conditions that control plot clearing.
Data collection resolution.
Maximum number of samples.
Refer to the discussion on XY plot definition in the Configuration instruction for an explanation of data source and for the
procedures to define a plot (Table 1-3 lists instruction numbers). Also, the instruction explains XY plot display configuration requirements.
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Tag or Trend XY Plot
Plot Display
Standard XY plot display templates in varying sizes are provided. These sizes range from a full size display to ½-size. An
XY plot display is normally called by name, from a keyboard
function key, and from an annunciator display panel pushbutton. Figure 15-1 is an example plot display. The display was
created using the XYPFL5.DT source file.
TC00381A
Figure 15-1. XY Plot Display
A single XY plot element can present data for up to five pairs of
variables. The data plots as either a single point, a series of
dots, or a continuous line on an x,y graph. A cross hair (+)
pointer indicates the most recently plotted point. The position
of the pointer updates as new values are received. Each plot
and its pointer are identified by a specific color on the graph.
The resolution of a plot determines how often the display
updates. Data is collected at a rate set during plot definition.
The definition pages allow activating or deactivating data
collection. For a tag plot, the resolution can range from
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seconds to days. A trend plot resolution is either 15 seconds or
one minute.
Plot Attributes
The attributes of a plot appear at the right of the display
(Fig. 15-1). The color of a plotted point associates it with a pair
of attribute boxes. For example, a plot in green corresponds to
the attribute boxes identified with a green selector. The top box
in the pair contains the x-axis attributes. The bottom box in
the pair contains the y-axis attributes. Figure 15-2 identifies
the attributes that appear for each variable of a tag or trend
plot.
TAG N AM E
PL OT S ELE C TO R
A
VA R IAB LE
X-A XIS
VA R IAB LE
Y-A XIS
EN G IN E ER IN G U N IT
D E SC R IP TO R
TAG 1
76.26 D E G K
21.000
H2
CC
100.00
1.0000
TAG 2
76.26 D E G K
21.000
H2
61.000
1.0000
AL AR M
STAT U S/Q UALIT Y /G R O U P
CURRENT
VA LU E
U P DAT E
MODE
H IG H S C ALE
LO W SC A LE
LA ST
P LOT T ED VA LU E
T0 1 5 2 1 A
Figure 15-2. XY Plot Attributes
During plot definition, two tag names are entered: One for the
x-axis variable and the other for the y-axis variable. The name
is of the tag that references the function block from which the
plot is collecting data. These tag names are required to present
real-time, dynamic information for each variable of a plot. The
tags are required whether the plot is a tag or trend plot.
Alarm Status/Quality/
Group
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An alarm status/quality/group field shows the current alarm
information being reported for the variable (tag). All normal
alarm indications appear in this field. An alarm can be
acknowledged using normal alarm processing procedures.
Refer to Section 12 for alarm processing procedures and for a
description of alarm conditions and indications.
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Tag or Trend XY Plot
Current Value
The current value is the value currently being exception
reported for the process point. The field updates to reflect any
changes in the process variable.
Engineering Unit
Descriptor
The engineering unit descriptor (EUD) is the unit of measurement for the variable. A control module reports an EUD index
number to select the appropriate engineering unit descriptor.
High and Low Scale
Limits
Initially, the scale limits are the high and low scale limits
entered during plot definition. These limits can be changed to
adjust the presentation after calling a display. These are local
display changes only. A scale limit change does not affect the
plot definition.
Last Plotted Value
Plot Legend
The last plotted value is the most recently plotted value. The
field updates as each new value is plotted.
A legend can be incorporated into a custom XY plot display
during its creation if desired. The plot definition defines the
text of the legend.
Tag Name
The tag name is the name of the tag associated with the plot.
This is the tag entered during plot definition.
Update Mode
An update mode indicator identifies the current mode for the
plot. The initial indication is the update mode set during plot
definition.
The mode indicator appears as:
SP - single point
MP - multipoint
CC - continuous curve
OC - operating curve
Using plot functions, the mode can be temporarily changed
between SP, MP, and CC modes. Only through plot definition
parameters can the OC mode be enabled or disabled.
Plot Control
XY plot control options can be used to adjust the plot presentation, specifically the scale limits and update mode. The
changes made while a plot display is on the screen are temporary. After exiting, the display resets to its default presentation
for the next call-up.
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Selecting a Plot
The control features function on a per plot basis. To change
the presentation with the control commands, select one of the
plots. Press the key identified by the selector character or use
a touch point. An X TARGT MODE field appears and the element highlights when selected. The control prompt location
depends on parameters defined during display creation, but
normally it appears under the attributes boxes. The X portion
indicates the currently selected and active plot for control (i.e.,
A, B, C, D, or E). The following sections explain the control
options for a plot.
Setting the Scale Limits
The scale change command (SC) adjusts the high and low
scale range. To change the scale limits for a selected plot:
1. Enter SC in the X TARGT MODE field, then press ENTER. An
input cursor appears on the high scale limit of the plot. After
the input cursor is enabled, it can be moved between the scale
limits by pressing TAB or TAB BACK.
2. Enter a new high and low scale limit, then press ENTER.
Both the high and low scale can be changed or only one limit if
desired. Any current and historical values will conform to the
newly entered range.
3. Press ESC to remove the input cursor.
Changing the Mode
A plot defaults to the update mode set during its definition.
Plot options allow changing the update mode while the plot is
on the display.
The update modes are:
Single point (SP) - the plot is updated as a single point. The
most recently plotted value is identified by the cross hair (+).
Historical points do not appear in this mode.
Multipoint (MP) - all plotted points remain on the screen as a
series of dots. The most recently plotted point is identified by
the cross hair.
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Continuous curve (CC) - all plotted points connect as a line.
The most recently plotted point is identified by the cross hair.
Operating curve (OC) - all plotted points are connected in the
order that they are received. The most recently plotted point is
identified by the cross hair.
For the continuous curve and multipoint plots, up to 480 samples can appear on the graph at one time. When the maximum
is reached, the last plotted point scrolls off the graph.
A clear feature can be implemented during definition to clear
plotted values after a certain trigger condition is met. If
enabled, a plot will clear after a certain number of samples,
after a specified amount of time, or when a trigger tag trips.
To change the mode of a selected plot, enter one of the following commands in the X TARGT MODE field, then press ENTER:
SP - single point mode
MP - multipoint mode
CC - continuous curve mode
Calling Help
A help option (HP) is available at any time to call a list of valid
XY plot commands. To call a list of plot options, enter HP in
the X TARGT MODE field, then press ENTER. A partial list of
available commands appears at the bottom of the window.
Press NEXT PAGE or PREV PAGE to view the complete list. The plot
options are:
SC - Scale Change
HS - History
BF - Background File
SF - Save into File
ED - Edit File
CL - Clear the Plot
HP - Help
SP - Single Point
MP - Multi Point
CC - Continuous Curve
Plot Data Background Curve
A snapshot of the currently plotted data can be saved. The
data is saved in a file with a user-defined name. After being
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saved, the plot data can be called back to the display as a
background plot at any time by entering its name. Each plot
file contains information for a single plot, not the entire display. An option for editing this data or creating this background data is also provided.
Commands for saving, viewing, and editing plot data files are
entered in the X TARGT MODE field. The commands include:
SF - save collected plot coordinates to file
ED - edit a file
BF - display a background file of plotted coordinates
CL - clear the background curve from plot the display
Saving Plot Coordinates to a File
The save to file (SF) command saves plot data to a file. To save
the plotted data for a selected plot:
1. Enter SF in the X TARGT MODE field, then press ENTER. A
FILE NAME field appears.
2. Enter a file name of up to eight alphanumeric characters,
then press ENTER. The name given to a background file should
be meaningful. Control returns to the X TARGT MODE field
after the operation is complete.
The background files are kept in a single directory
([DATA.USN59]
[DATA.USN59])
[DATA.USN59] in order to group them for transfer.
Editing a File
The edit (ED) command builds or modifies a background file.
To edit:
1. Enter ED in the X TARGT MODE field, then press ENTER. A
FILE NAME field appears.
2. Enter the name of an existing file to edit or enter a new
name to create a background file, then press ENTER. If the file
exists, it displays on the graph as a background curve. If the
file does not exist, a curve can be built.
An XY: XXXXXX YYYYYY field appears after entering the file
name. The XXXXXX portion is the x-axis value and the
YYYYYY portion is the y-axis value. The input field is used to
edit the x- and y-axis values to either change the background
curve or to build a background curve.
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To edit the coordinates of a background file:
1. Press:
To move the input field between the coordinate
fields. Key in a new coordinate value if desired.
2. Press TAB and TAB BACK to view the next or previous coordinate pair respectively. The display updates after pressing
either key.
3. Repeat Steps 1 and 2 for each coordinate pair until the
desired presentation is created.
4. Press ENTER to save all changes to the background file.
Press ESC to abandon the changes and return control to the X
TARGT MODE field.
Displaying a Background File
The background file (BF
BF)
BF command calls a previously saved set
of coordinates. To call a background file:
1. Enter BF in the X TARGT MODE field, then press ENTER. A
FILE NAME field appears.
2. Enter the name of a file that was created using either the
SF or ED command, then press ENTER.
A continuous curve is drawn from the data contained in the
background file. Its color is always white. The data from only
one file can display at a time.
A background file can be deleted from the hard disk at any
time. Refer to the File Utilities instruction for a description of
the delete command (Table 1-3 lists instruction numbers).
Clearing a Background Curve
The clear command removes the background curve from the
plot. To clear a background curve, enter CL in the X TARGT
MODE field, then press ENTER.
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Trend History
The history command (HS) calls historical trend data for a
trend plot. The data plots as a background curve. To call historical trend data:
1. Enter HS in the X TARGT MODE field, then press ENTER. An
X START TIME field appears.
2. Enter a starting time and date, then press ENTER. For
example:
18:50:45 13-APR-96
The retrieved data appears in a background curve. Use the CL
command to clear the background curve.
MFC Data Source XY Plot
An MFC data source plot uses data collected by a program
running in a control module (except MFC module). The variables that are plotted come from a data file transferred to the
workstation from the module. Normally, the control module
executes a C language program to collect data. It sends the
data to the workstation in real-two format.
A plot definition determines which data file is associated with
a given plot. Each plot definition has a unique index number.
Parameters defined during plot display creation reference the
index number of a plot definition. This determines the data
that is initially displayed when the plot display is called.
Another data file can be selected for the display, however, at
any time after calling the display.
A data file resides in the [DATA.USN59] directory and is in the
format:
XYxxnnnn.IF
where:
xx
nnnn
Plot index number.
File ID as defined in the plot definition.
For example, the file XY151234.IF corresponds to the plot definition with an index number of 15 and a file ID of 1234.
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The characteristics of an MFC data source plot are set up during plot definition. Specifically, plot definition identifies:
•
•
•
•
•
•
•
•
Data source as MFC.
File ID.
HAC or MFP module address.
Trigger tag.
Initial x-axis high limit and low limit.
Border color.
Reference line colors.
Plot legend.
Refer to the discussion on XY plot definition in the Configuration instruction for an explanation of data source and for the
procedures to define a plot (Table 1-3 lists instruction numbers). Also, the instruction explains XY plot display configuration requirements.
Plot Display
An XY plot display can contain up to three MFC data source
plots. Each plot presents the data from a single data file. The
data can be plotted as a smooth curve or in steps on an x,y
graph. This is determined by the data file and not the workstation. A maximum of 480 samples can be plotted for a single
plot.
The update of a plot depends on the program collecting the
data. When the trigger tag of a plot goes from zero to some file
size, the module sends a data file to the workstation. The trigger tag is an ANALOG type tag that references an analog
exception reporting block in a control module.
A new data file from the module overwrites any existing data
file. The new data file is read to update the display. If a data
file for a plot has not been received, the display remains blank
and the following message appears until the data becomes
available:
No data from the module for plot index n
The data file contains parameters that set the high scale and
low scale limits for a plot. Data values are plotted
proportionally between the high and low scale limits. Any values that fall outside these limits are not plotted.
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The module can mark a data point as being in alarm. The display shows an area on the plot line in red to indicate when a
point was in alarm.
A single plot element can contain up to five reference lines. The
lines can be drawn in either a vertical or horizontal direction.
The data file enables the reference lines. The plot definition
sets the color of each line.
Plot Attributes
The attributes that appear for an XY plot and where they
appear on the display are determined during display creation.
The values come from a data file. During display creation, the
plot display can be designed to include the following
information.
Description
The description is the text entered as the plot description during its definition.
Plot Legend
A plot legend can be incorporated into a display during its creation if desired. The plot definition defines the text of the
legend.
Reference Line Value
Up to ten reference line values can be displayed. A reference
line value field can show either the x-axis value or y-axis value
for a reference line. Up to five reference lines are possible for a
plot.
Update Mode
The initial update mode is the update mode set during plot
definition. The continuous curve (CC) mode is recommended
for MFC data source plots.
X-Axis and Y-Axis Scale
Limits
The initial x-axis and y-axis scale limits are set during plot definition. The data file contains values that override these initial
values.
X-Axis and Y-Axis Last
Value
The x-axis and y-axis last value is the last value retrieved from
the data file for either or both the x-axis and y-axis.
Plot Control
Using XY plot control, a plot display can be switched between
different data files while the display is on the screen. This
eliminates the need to have several dedicated displays for a set
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of plots if desired. The control features are set on a per plot
basis.
Initially, a plot element of a display shows the data from a specific plot definition. A parameter defined during display creation selects the plot definition used by the element initially.
At any time after calling an XY plot display, another active
MFC data source plot definition (data file) can be called to the
display to replace the current data file. Some restrictions
apply, however, when selecting a different plot definition.
Selecting a different plot definition (data file) affects only one
plot element at a time. The change is only temporary and after
exiting, the element resets to the plot definition selected for it
during display creation.
To call another data file from the current XY plot display:
1. Select one of the plot elements. Press the key identified by
a selector character or use a touch point. An X TARGT MODE
field appears. The X portion indicates the currently selected
and active plot for control (e.g., A, B, or C). The control prompt
location depends on display creation.
2. Enter the index number of an active MFC data source plot.
A valid entry is from 1 to 80.
3. Press ENTER.
A plot must be active to call it to the display. Up to ten MFC
data source plots can be active at one time. If the plot being
called is not active, the following message appears:
Plot must be ACTIVE in order to continue
A plot must be of MFC data source type to call it to the display.
If not, the following message appears:
Plot is not of MFC Data Source Type
Up to six plot elements can be on display at one time, but only
three in a single window. If the entered plot index is already
displaying in the current window, the following message
appears:
Plot already on display
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If the same display is called in a different window, changing
plot index is not permitted. If an attempt is made to change the
index, the following message appears:
Same display on CRT n cannot change plot
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