ML20198B146
| ML20198B146 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 03/08/1984 |
| From: | PUBLIC SERVICE CO. OF COLORADO |
| To: | |
| Shared Package | |
| ML20198B035 | List: |
| References | |
| DD-SLS-1, NUDOCS 8511060307 | |
| Download: ML20198B146 (11) | |
Text
,
PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VR AIN NUCLE AR GENER ATING ST ATION ISSUE A Page 1 of 11 DESIGN DIRECTIVE FOR SCREEN LAYOUT AND STRUCTURING TfifPA D BY-REVIEWED BY:
APPROVED BY:
J - Wo ha
%( ALa Gy
/
(jg FOREWORD:
Computer Cathode Ray Tube (CRT) displays are a valuable source of information to both Fort St.
Vrain ( FSV) control room operators and other technical support activities.
The effective value of the presented information is directly related to the users success in retrieving and interpreting that information.
The adoec stress of aonormal operating situations places emphasis on the need for consistency of methods and the application of basic Human Engineering Factors during design activities.
This Design Directive presents the Human Factors and other considerations necessary to support effective retrieval, recognition and understanding of displayed data.
Additional guidance directed toward the actual CRT selection and placement (location) of CRTs is contained in associated directives, CRT-1 and CRL-1 respectively.
SELECTION CONSIDERATIONS I.
DATA PRESENTATION FORMAT Data presented for operator use shall be organized and formatted in a clear, orderly and consistent manner.
The primary consideration shall be in preventing reading, selection, and interpretation errors and in reducing search time.
A.
ORGANIZATION OF DATA 1.
Displayed data shall be organized in a logical, consistent manner.
2.
Displayed data shall reflect some obvious and inherent quality of the data groups (e.g.,
hierarchial, sequential, or mimic relationsnips).
3.
Physical location of specific data groups (e.g., alarms, menus) on the screen shall be 8511060307 051029 consistent.
DR ADOCK 05000267 PDR l
F ORM 372 22 - 3643
PUBLIC SERVICE COMPA NY OF COLORADO FORT ST. VR AIN NUCLE AP GENE R ATING STATION DD-SLS-1 ISSUE A Page 2 of 11 Organization and separation of information 4.
subgroups shall be made apparent to the operator through the use of blank spaces,
- lines, or some other form of visible demarcation.
B.
USABILITY OF DATA 1.
Data should be presented to the operator in a readily usable format.
2.
There shall be no requirement for transposing, computing, interpolating, or mentally transisting displayed data into other units or numerical bases.
C.
MENU DESIGNATORS 1.
Numbers shall be used as designators when listing selectacle items.
2.
Numerical designators shall start with the number "1" (not zero).
3.
If the use of numbers as designators would create confusion because of other numbers which make up the item to be designated, alphabetic characters shall be used.
4.
When used, alphabetic designators shall start with the letter "A".
5.
Selection designators in menus shall be separated from text descriptors by at least one blank space.
D.
LISTS 1.
Li sts shall be vertically aligned and lef t-justified.
2.
Lists containing high use options shall be organized with high probability of use items presented first.
3.
Non-option lists of equal probability options shall be presented in alphabetical or numerical order.
FORM 372 22 3643
PUBLIC SERVICE COMPANY OF COLORADO FORT ST. vRAl:. NUCLE AR GENER ATING STATION DD-SLS-1 ISSUE A Page 3 of 11 E.
TABLES AND GRAPHS Quantitative data which must be scanned and compared shall be presented in either tabular or graphic form.
F.
STANDARDIZED FIELDS The following standardized fields shall be used:
1.
Telephone Number: (514) 555-1212 2.
Time: HH:MM:SS, HH:MM, MM:SS:(S) 3.
Data: MM:DD:YY II.
SCREEN LAYOUT and STRUCTURING CONSIDERATIONS Screen layouts and structuring of data presented on CRTs shall minimize operator scanning and reading requirements, and minimize the probability of operator error.
A.
TEXT PRESENTATION 1.
SEPARATION OF PARAGRAPHS Paragraphs in continuous text excluding data displays shall be separated by at least one blank line.
2.
MULTIPLE-PAGE CDNSIDERATIONS a.
Page Designation When data are contained on multiple pages, each page shall display both page number and total numcer of pages.
b.
Continuous Numbering Items contained in a numbered list and described on " continue" pages shall be numbered relative to the first number on the first page of the list.
3.
PLACEMENT OF INSTRUCTIONS Wnen directions to the operator accompany a list of options, such directions shall precede presentation of the list, or be readily available via function key selection.
FORM 312-22 3643
PUBLIC SERVICE COMPA N Y OF COLORADO
~
FORT ST. VR AIN NUCLE AR GENER ATING STATHDN ISSUE A Page 4 of 11 4.
CHARACTER GROUPING a.
When 5 or more digits and/or non-text alpha-numerics are displayed, and no natural (i.e.,
population stereotyped) organization exists, characters shall be grouced in blocks of 3 to 4 characters each.
b.
Groups shall be separated by a minimum of 1 blank character space.
5.
USE OF CURSOR In presentations in which selection is made by use of a cursor, formats shall be organized to minimize positioning movements of the cursor.
6.
SCREEN LOADING The amount of information-bearing activated screen area shall not exceed 25% of the total screen area.
This does not include demarcation lines used to separate groups of data.
7.
TREND PLOT SCALES CRT displayed trend plot scales should be consistent with the intended functional use of the data.
(For example, the monitoring of neutron flux at reactor trip may have a variable scale of 0% to 100% of the design value and a time scale resolution of seconds.
- Hcwever, post-trip monitoring may have a variable scale of OS to 10'. with a tire scale resolution of minutes.
Finally, operational log data of neutron flux may have a time scale resolution of hours.)
8.
GRAPHICAL PRESENTATION When tne operator is required to scroll or pan on a large ogical
- frame, location or functional references shall be provided in the viewable portion of the frame.
FOAV 372 22 3643
PUBLIC SERVICE COMPANY OF COLORADO FORT ST VR AIN NUCLE AR GENE R ATING STATION
~.
DD-SLS-1 1SSUE A Page 5 of 11 C.
LABELING 1.
LABEL PLACEMENT Labels shall be located in a consistent manner either above or to the left of the data group or message they cescribe.
2.
LABEL ORIENTATION a.
Functional or nomenclature labels shall be oriented horizontally.
b.
Paging functions may be oriented vertically along the edge.
3.
LABEL HIGHLIGHTING a.
Labels shall be highlighted or otherwise accentuated to facilitate operator scanning and recognition.
b.
The technique used to highlight labels shall be easily distinguished from that used to highlight emergency or critical messages.
4.
OPTION LABELS When presenting a list of operator options, the label shall reflect the question or,
choices being posed to the operator.
III. MESSAGES Messages shall provide the ocerator with the information necessary to complete a specific action, error recovery or decision sequence and shall be clear, concise and readily useable.
A.
MESSAGE TYPE MESSAGES ARE OF 3 TYPES 1.
Prompts.
Used to provide directions to the operator for initiating and/or completing an action involving the computer system.
FORY 372 22 3643
PUBLIC SERVICE COMPANY OF COLORADO o
FORT ST. VRAIN NUCLE AR GENE R ATING STATION DD-SLS-1 ISSUE A Page 6 of 11 a.
Prompts shall be displayed whenever the operator may need directions or guidance to initiate or complete an action or sequence of actions.
b.
Prompts shall contain clear and specific cues and instructions which are relevant to the action to be taken.
c.
Directions shall be placed in the prompt information sequence to be used by the operator.
2.
Error messages.
Used to inform the operator of invalid or incorrect inputs to the system, a.
Whenever an operator error or invalid input is detected, an error message shall be displayed.
b.
Capability shall be provided for operator correction of individual errors without affecting adjacent valid
- entries, c.
Error messages s:"ll inform the operator that corrective action is required.
3.
Feedback.
Used to indicate to the operator the status of the computer system and/or the controlled / monitored
- system, following an operator input or action.
a.
Feedback messages shall be provided to the operator to indicate changes in the status of system functioning.
b.
When a displayed message or datum is selected as an option or input to the
- system, the subject item shall be highlighted, or otherwise positively identified, to indicate acknowledgement by the system.
c.
When system functioning requires the operator to stand by, such as wnen the computer is searching for reauested
- data, periodic feedback shall be provided to the operator to indicate normal system operation and the reason for the delay.
FOnM 372 22 3643
- s.,
PUBLIC SERVICE COMPANY OF COLORADO FORT ST VRAIN NUCLEAR GENER ATING ST ATION TSSUE A Page 7 of 11 d.
When a process or sequence is completed
~
by the system, positive indication shall be presented to the operator concerning the outcome of the process and requirements for subsequent operator actions.
4.
URGENT MESSAGES a.
Urgent messages requi ring immediate operator response shall be highlighted to attract the operator's attention.
b.
Urgent messages shall always be displayed in the same location.
IV.
COLOR UTILIZATION, GRAPHIC CODI,NG and HIGHLIGHTING A.
COLCR SELECTION AND UTILIZATION 1.
Colors used on the CRT to convey information shall be consistent in use and meaning.
2.
COLOR MEANINGS When color is used, the meaning of the colors shall, where applicable, equate with the commonly understood meaning of those colors.
3.
REQUIRED UTILIZATION
'ed, The following specific meanings for r
- green, and yellow shall apply when these colors are used in CRT displays.
Good attention getting color.
Denotes Red unsafe condition, danger, immediate operator action required, or critical parameter value out of tolerance.
Green A
non-attention getting color.
Cenotes safe condition, no operator action
- required, or parameter value is within tolerance.
Good attention getting color.
Yellow / Amber Denotes hazard, potentially unsafe, caution, attention required, marginal parameter value exists.
FOAM 372 22 3643
PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VR AIN NUCLEAR GENER ATING STATION DD-SLS-1 ISSUE A Page 8 of 11 4.
OPTIONAL COLOR UTILIZATION a.
Black - Normally used as the background color, i.e, the color of blank character spaces.
Also used as the action character when reverse field coding is employed.
~
b.
White - A non-attention getting color.
It should be used for standard alphanumeric text or tables where the information is contained in the characters and not the color.
Might also be used for labels, coordinate
- axes, dividing
- lines, demarcation brackets, etc.
c.
Cyan (light blue) - (Same as white) -
Might be used in conjunction with white to provide some amount of non-critical discrimination (e.g.,
use cyan for tabular column headings and demarcation lines; use white for alphanumeric data).
d.
Blue (dark)
Poor contrast with dark background.
Not recommended for attention getting purposes or for information-bearing data.
Use for labels and other advisory type messages.
A harsh color to the eye.
e.
Magents Should be used sparingly, and for attention getting purposes.
f.
Orange Good attention getting color.
Care must be taken that hue is selected to be readily differentiable from red, yellow and white.
5.
RED-GREEN COMBINATIONS a.
Whenever possible, red and green colors shall not be used in combination.
b.
Use of red symbols / characters on a green background shall especially be avoided.
FORM 372 22 3643
PUBLIC SERVICE COMPA NY OF COLORADO 3
FORT ST. vR Al'. NUCLE AR GENER ATING ST ATio,
DD-SLS-1 ISSUE A Page 9 of 11 B.
GRAPHIC CODING Graphic coding methods (e.g.,
- symbols, boxes, underlines, colors) shall be used to present standard qualitative information to the operator or to draw the operator's attention to a particular portien of the display.
1.
GRAPHIC CODE CONSISTENCY a.
Graphic codes, used separately or in combination, shall have the same meaning in all applications.
b.
Representative symbols symbols characterizing system components shall be consistent in all applications.
2.
Geometric Shape Coding - When geometric shape (symbol) coding is
- used, the basic symbols shall vary widely in shape.
3.
NUMBER OF NON-REPRESENTATIVE SYMBOLS a.
The number of basic symbols used for coding shall be kept small.
The maximum number under optimum display conditions should be 20.
The maximum number under adverse display conditions should be 6.
b.
When needed, other highlighting and graphic tecnniques (color, filled versus
- unfilled, and other " modi fiers") shall be used to display different states or qualities of a basic symbol.
C.
HIGHLIGHTING Highlighting may be used to attract the operator's attention to any displayed data item or message which is important to decision making or action requirements.
cEv 372 22 3642
PUBLIC SERVICE COMPA N Y OF COLORADO FORT ST. VR AIN NUCLE AR GE*,ER ATING STATION ISSUE A Page 10 of 11 1.
CONSISTENT APPROACH a.
Highlighting methods which have information value beyond their attention getting quality shall have the same meaning in all applications.
b.
Highlighting methods associated with emergency conditions shall not also be used in association with normal conditions.
2.
Contrast Enhancement When contrast enhancement (i.e.,
increased illumination intensity level) is used for highlighting, not more than two (preferable) or three (maximum) brightness levels shall be used in a single preser.tation!
3.
Flicker or Blinking - Blinking of a symbol or message (e.g., ON-OFF or alternating high-low brightness) for purposes of highlighting shall be reserved for emergency conditions or similar situations requiring immediate operator action, a.
When blinking is used for highlighting, a maximum of 2 blink rates shall be used.
b.
When a single blink rate is used, the rate shall approximate 2-3 " blinks" per second with a minimum of 50 msec "on" time between blinks.
c.
When 2 blink rates are used, the fast blink should approximate 4 per second and the slow blink shall approximate 1 per second.
d.
When 2 blink rates are used, the "on-of f" ratio shall approximate 50*;.
e.
When 2 blink rates are used, the Figher rate shall apply to the most critical information.
FORV 372 22-3643
PUBLIC SERVICE COMPAN Y OF COLORADO FORT ST. VR AIN NUCLEAR GENEFATING STATION CD-SLS-1 TSSUE A Page 11 of 11 Image reversal (e.g., dark 4.
Inverse Video characters on a light background) shall be used primarily for highlighting in cense data
- fields, such as a word or phrase in a
paragraph of text, or a set of characters in a table of data.
ASSOCIATED DIRECTIVES 00-00-1
- Requirements and Guidance for Preparing Design Directives DD-CRL Cathode Ray Tube Location DD-CRT Cathode Ray Tube Selection DD-KEY Keyboard SOURCE MATERIALS AND REFERENCES NUREG - 0700 Human Factors in Engineering McCormick, 1976.
FOAV 372 22 3643