Omron NX-SL series

3 Safety Standard Function Blocks
3 - 6
NX-series Safety Control Unit Instructions Reference Manual (Z931)
The following figure shows a programming example and timing chart for a PV of INT#5.
• Use the SF_CTD instruction to create a counter that decrements the counter value each time the
counter input signal is received.
• Use the SF_CTUD instruction to create a counter that is both incremented and decremented.
Additional Information
CU=A
Reset=abc
CV=ghi
Q=def
CV is incremented as soon
as Reset changes to FALSE.
When CV reaches PV,
Q changes to TRUE.
When Reset changes to TRUE,
CV is set to 0 and Q changes to
FALSE.
PV=INT#5
TRUE
FALSE
TRUE
FALSE
TRUE
FALSE
0