Omron NJ501-1500

2 Instruction Descriptions
2-144
NJ-series Instructions Reference Manual (W502)
The following table shows the relationship between Reset, Load, CV, QU, and QD. This assumes that
the value of PV is larger than 0.
The following figure shows a programming example and timing chart for a PV of INT#3.
Reset Load CV QU QD Operation
FALSE FALSE
0 or
lower
FALSE TRUE Only up counter operation is performed.
• CV is incremented when CU changes to TRUE. It is
not decremented when CD changes to TRUE.
Between
0 and PV
FALSE FALSE Both up and down counter operation is performed.
• CV is incremented when CU changes to TRUE and
decremented when CD changes to TRUE.
PV or
higher
TRUE FALSE Only down counter operation is performed.
• CV is decremented when CD changes to TRUE. It is
not incremented when CU changes to TRUE.
TRUE FALSE 0 FALSE TRUE The up counter is reset.
• The value of CV is set to 0.
FALSE TRUE PV TRUE FALSE The down counter is reset.
• The value of CV is set to PV.
TRUE TRUE 0 FALSE TRUE The up counter is reset. Reset take priority over Load.
• The value of CV is set to 0.
CTUD_instance(A, B, abc, def, INT#3, ghi, jkl, mno);
LD ST
A
jkl
ghi
mno
INT#3
abc
def
B
CTUD
CU QU
CD QD
Reset CV
Load
PV
CTUD_instance