Omron NJ501-1500

2-41
2 Instruction Descriptions
NJ-series Instructions Reference Manual (W502)
Sequence Input Instructions
2
R_TRIG (Up) and F_TRIG (Down)
The following figure shows a programming example and timing chart.
z F_TRIG
F_TRIG assigns TRUE to output signal Q for one task period only when input signal Clk changes to
FALSE. Otherwise, the value of Q is FALSE. In the first task period in which this instruction is executed,
the value of Q is FALSE regardless of the value of Clk. If the value of Clk is FALSE when the power sup-
ply is turned ON, the value of Q remains FALSE until the value of Clk changes to TRUE and then back
to FALSE.
z Down
The functions of the F_TRIG instruction and the Down instruction are exactly the same. The Clk vari-
able of the F_TRIG instruction corresponds to the In variable of the Down instruction. The Q variable
corresponds to the Out variable.
The following figure shows a programming example and timing chart.
R_TRIG_instance(A, abc);
LD ST
R_TRIG
abc
A
R_TRIG_instance
Clk Q
LD
abc
A
Up
In
TRUE
FALSE
TRUE
FALSE
Task period
Clk, In
Q, Out=abc
F_TRIG_instance(A, abc);
LD ST
F_TRIG
abc
A
F_TRIG_instance
Clk Q
LD
abc
A
Down
In
TRUE
FALSE
TRUE
FALSE
Task period
Clk, In
Q, Out=abc