12.8 Counter Function Module
12.8.1 What Is the Counter Function Module?
12
Function
s
of the Contr
oller
S
ection
12-57
PI Latching
PI latching is used to record (i.e., latch) the current count at the moment (i.e., on the rising edge
detection point) when an external signal is input to the recording register (IL
06) as PI latch-
ing data.
A discrete input (DI latching) or the phase-C pulse (phase-Z latching) is selected as the external
signal.
The time changes from when the PI latching request is made until the rising edge point of the
external input signal is detected and the PI latching data is stored are illustrated in the following
figure.
*1.
After the discrete input changes from ON to OFF, it cannot be turned ON again for at least 500 ms.
*2.
If you use a 5-V or 12-V input, the discrete input cannot be turned ON again for at least 1
μ
s after it is turned
OFF.
If you use a 24-V input, the discrete input cannot be turned ON again for at least 2
μ
s after it is turned OFF.
0
DI latching (di
s
crete input): 60
μ
s
min.
*1
Pha
s
e-C pul
s
e (pha
s
e-Z input): 1
μ
s
min.
*2
(+)
(-)
PI latching regi
s
ter
s
torage
PINT (PI latching data)
Hardware latching
PI latching detection
reque
s
t
s
ignal
External input
s
ignal
(di
s
crete input or pha
s
e Z)
PI latching completion
s
ignal
Time (
s
)
PI latching data
Ri
s
ing edge detection point
Curr
ent count
