13.27
Date Code 20171006 Instruction Manual SEL-400 Series Relays
SELOGIC Control Equation Programming
SEL
OGIC Control Equation Operators
The argument of an R_TRIG statement must be a single bit within the relay. An
example of the relay detecting a rising edge of a calculated quantity is shown in
Example 13.10.
F_TRIG
F_TRIG is a time-based function that creates a pulse when another value
changes, as shown in Example 13.10. Use F_TRIG to sense when a value
changes from logical 1 to logical 0 and take action only after the value changes
state. The F_TRIG output is a pulse of one protection processing interval dura-
tion (typically 1/8th cycle). This pulse output asserts one processing interval after
the monitored element deasserts.
Figure 13.9 R_TRIG Timing Diagram
Example 13.10 R_TRIG Operation
The SELOGIC control equation below is invalid.
PSV15 := R_TRIG (PSV01 AND PSV23) # Invalid statement, do not use
Use a SEL
OGIC control equation variable to calculate the quantity and then
use the R_TRIG operation on the result, as shown below.
PSV14 := PSV01 AND PSV23 # Calculate quantity in an intermediate
result variable
PSV15 := R_TRIG PSV14 # Perform an R_TRIG on the quantity
Relay Word bit
A
R_TRIG A
R_TRIG A
Deasserts
R_TRIG A
Asserts
Relay Word bit A Changes
from 0 to 1
1
Processing
Interval
1
Processing
Interval
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