4.195
Date Code 20170927 Instruction Manual SEL-751 Relay
Protection and Logic Functions
Front-Panel Settings (SET F Command)
Display Points
Use display points to view either the state of internal relay elements (Boolean
information) or analog information on the LCD display. Although the LCD
screen displays a maximum of 16 characters at a time, you can enter as many
as 60 valid characters. Valid characters are 0–9, A–Z, -, /, ", {, }, space. For
text exceeding 16 characters, the LCD displays the first 16 characters, then
scrolls through the remaining text not initially displayed on the screen.
Boolean Display Point Entry Composition
Boolean information is the status of Relay Word bits (see Appendix K: Relay
Word Bits). In general, the legal syntax for Boolean display points consists of
the following four fields or strings, separated by commas:
Relay Word Bit Name, “Alias”, “Set String”, “Clear String”.
Any or all of Alias, Set String, or Clear String can be empty. Although the
relay accepts an empty setting Name as valid, a display point with an empty
Name setting is always hidden (see the following). Commas are significant in
identifying and separating the four strings. Use quotation marks only if the
text you enter for Alias, Set String, or Clear String contains commas or spaces.
For example, DP01 = Name, Text is valid, but Name, Alias 3 is not valid (con-
tains a space). Correct the Alias name by using the quotation marks: Name,
“Text 3”. You can customize the data display format by entering data in
selected strings only. Table 4.92 shows the various display appearances result-
ing from entering data in selected strings.
Hidden (No Display)
A display point is hidden when settings are entered (DPn = XX, where n = 01
through 32 and XX = any valid setting), but nothing shows on the front-panel
display. Table 4.92 shows examples of settings that always, never, or condi-
tionally hide a display point.
NOTE: The rotating display is
updated approximately every two (2)
seconds.
where:
Name = Relay Word bit name (IN101, for example). All binary
quantities occupy one line on the front-panel display (all
analog quantities occupy two lines).
Alias = A more descriptive name for the Relay Word bit (such as
TRANSFORMER 3), or the analog quantity (such as
TEMPERATURE).
Set String = State what should be displayed on the LCD when the
Relay Word bit is asserted (CLOSED, for example)
Clear String = State what should be displayed on the LCD when the
Relay Word bit is deasserted (OPEN, for example)
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