Chapter 8 Logic Instructions
8-55
Precautions for Correct Use
While Reset is TRUE, the counter will not count up.
When CV equals PV, the counter stops counting.
Programming Example
The variable table and program
CTU1_EN
BOOL
FALSE
Timing Chart:
Case 1: If CTU counts up normally, the value of CTU1_CV is increased by 1 whenever
CTU1_CU is triggered once.
Case 2: When CTU1_CV equals CTU1_PV, CTU1_Q is TRUE and CTU stops counting.
Case 3: When CTU1_Reset is TRUE, CTU1_CV is cleared to 0, CTU1_Q is FALSE. And the
counter will not count when CTU1_CU is triggered.
1
CTU
EN ENO
Q
CTU1
CU
Reset
CV
PV
CTU1_EN
CTU1_CU
CTU1_Reset
CTU1_PV
CTU1_Q
CTU1_CV
CTU1_CU
CTU1_Reset
CTU1_CV
CTU1_ Q
CTU1_PV
Case 1 Case 2
Case 3