Ctud - Omron NJ501-1500 Reference Manual

2 Instruction Descriptions

CTUD

The CTUD instruction creates an up-down counter that operates according to an up-counter input and a
down-counter input. The preset value and counter value must have an INT data type.
Instruction
CTUD Up-down Counter
Variables
Name Meaning
CU Up-counter
input
CD Down-
counter
input
Reset Reset
signal
Load Load signal
PV Preset
value
QU Up-counter
output
QD Down-
counter
output
CV Counter
value
Bit string
CU OK
CD OK
Reset OK
Load OK
2-142
Name FB/FUN
FB
I/O Description
Up counter input
Down counter input
TRUE: Reset CV to 0.
Input
TRUE: CV set to PV.
The final counter value
when operating as an up
counter
The initial counter value
when operating as a down
counter
TRUE: up-counter output
ON
FALSE: up-counter output
OFF
TRUE: down-counter output
Output
ON
FALSE: down-counter out-
put OFF
Counter present value
Graphic expression
CTUD_instance
CTUD
CU QU
CD QD
Reset CV
Load
PV
Valid range
Depends on data type.
0 to 32767
Depends on data type.
0 to 32767
Integers
NJ-series Instructions Reference Manual (W502)
ST expression
CTUD_instance (CU, CD,
Reset, Load, PV, QU, QD,
CV);
Unit Default
FALSE
---
0
--- ---
Times, durations,
dates, and text strings