4.85
Date Code 20100129
Instruction Manual
SEL-751A Relay
Protection and Logic Functions
Logic Settings (SET L Command)
Parentheses Operator ( )
You can use more than one set of parentheses in a SEL
OGIC
control equation
setting. For example, the following Boolean SEL
OGIC
control equation setting
has two sets of parentheses:
SV04 :=
(SV04 OR IN102) AND (PB01_LED OR RB01)
In the above example, the logic within the parentheses is processed first and
then the two parentheses resultants are ANDed together. Use up to 14 sets of
parentheses in a single SEL
OGIC
control equation setting. The parentheses
cannot be “nested” (parentheses within parentheses).
Math Negation Operator (–)
The negation operator – changes the sign of a numerical value. For example:
MV01 :=
RB01
When Remote bit RB01 asserts, Math variable MV01 has a value of 1, i.e.,
MV01 = 1. We can change the sign on MV01 with the following expression:
MV01 := –
1 * RB01
Now, when Remote bit RB01 asserts, Math variable MV01 has a value of –1,
i.e., MV01 = –1.
Boolean NOT Operator (NOT)
Apply the NOT operator to a single Relay Word bit and to multiple elements
(within parentheses).
An example of a single Relay Word bit is as follows:
SV01 :=
NOT RB01
When Remote bit RB01 asserts from logical 0 to logical 1, the Boolean NOT
operator, in turn, changes the logical 1 to a logical 0. In this example, SV01
deasserts when RB01 asserts.
Following is an example of the NOT operator applied to multiple elements
within parentheses.
The Boolean SEL
OGIC
control equation OUT101 setting could be set as
follows:
OUT101 :=
NOT(RB01 OR SV02)
If both RB01 and SV02 are deasserted (= logical 0), output contact OUT101
asserts, i.e., OUT101 := NOT(logical 0 OR logical 0) = NOT(logical 0) =
logical 1.
=
<>
equality
inequality
Boolean
AND
AND
Boolean
OR
OR
Boolean (lowest prece-
dence)
Table 4.33
SEL
OGIC
Control Equation Operators (Listed in Operator
Precedence)
(Sheet 2 of 2)
Operator
Function
Function Type (Boolean
and/or Mathematical)
Summary of Contents for 751A
Page 1: ...20100129 SEL 751A Feeder Protection Relay Instruction Manual PM751A 01 NB...
Page 6: ...This page intentionally left blank...
Page 12: ...This page intentionally left blank...
Page 18: ...This page intentionally left blank...
Page 26: ...This page intentionally left blank...
Page 92: ...This page intentionally left blank...
Page 218: ...This page intentionally left blank...
Page 250: ...This page intentionally left blank...
Page 376: ...This page intentionally left blank...
Page 392: ...This page intentionally left blank...
Page 408: ...This page intentionally left blank...
Page 418: ...This page intentionally left blank...
Page 434: ...This page intentionally left blank...
Page 462: ...This page intentionally left blank...
Page 544: ...This page intentionally left blank...
Page 580: ...This page intentionally left blank...
Page 584: ...This page intentionally left blank...
Page 632: ...This page intentionally left blank...
Page 636: ...This page intentionally left blank...
Page 640: ...This page intentionally left blank...