NORD Drivesystems BU0550 User Manual
Page 48
PLC logic for NORD SK 54xE frequency inverters
48
BU 0550 GB-0813
3.5.1.8
TOF switch-off delay
If IN = TRUE is set, Q is set to TRUE. The timer starts if IN changes to FALSE. As long as the timer is
running (ET < PT) Q remains set to TRUE. The timer stops if (ET = PT) and Q then becomes FALSE. With
a new rising flank on IN, the timer ET is reset to zero.
Here, literals can be used for simplified input, e.g.
LD TIME#50s20ms
= 50.020 seconds
LD TIME#1d30m
= 1 day and 30 minutes
IN
Q
PT
ET
Table 66 TOF switch-off delay
NOTE
The time ET runs independently from the PLC cycle. Starting of the timer with IN and setting of
the output Q is only executed with the function call-up "CAL". The function call-up takes place
within a PLC cycle. However, with PLC programs which are longer than 5 ms this may result in
the occurrence of jitter.
VAR_INPUT
VAR_OUTPUT
Input
Explanation
Type
Output
Explanation
Type
IN
Timer active
BOOL
Q
TRUE
( ET<PT )
BOOL
PT
Duration
DINT
ET
Current timer reading
DINT