Mitsubishi Electric MELSEC-L02SCPU User Manual page 203

• Count range of the ring counter
The count range differs depending on the CH1 Current value (SD1880, SD1881) when preset is
performed or CH1 Count enable command (SM1895) is turned on, upper limit value and lower limit value.
Ex. When setting the ring counter lower limit value to -50000 and the ring counter upper limit value to 100000
(except for Range 3)
Count range
Range 1
+2147483647
Ring counter
upper limit value
Subtraction
Ring counter
lower limit value
-2147483648
Count range
-50000 to 99999
Range 2
+2147483647
Ring counter
upper limit value
Subtraction Subtraction
Ring counter
lower limit value
-2147483648
Count range
-2147483648 to -50000
100001 to 2147483647
Range 3
+2147483647
Ring counter
upper limit value=
Ring counter
Subtraction
lower limit value
-2147483648
Count range
-2147483648 to 2147483647
• Precautions
• The change of upper limit value and lower limit value of ring counter takes effect when rising edge of
CH1 Count enable command (SM1895) is detected. To enable the changed settings of these values
when CH1 Count enable command (SM1895) is on, turn off it for 2ms or more and then turn on it.
• When changing the count range by preset, perform it after turning off CH1 Count enable command
(SM1895) to prevent incorrect counts.
(
Ring counter
lower limit value
Addition
(
Ring counter
lower limit value
(
CH1 current value
(SD1880 and SD1881)
Addition Addition
(
CH1 current value
(SD1880 and SD1881)
(
Ring counter
lower limit value
Addition
The CH1 current value (SD1880 and SD1881) is not included in the setting condition.
CHAPTER 8 HIGH-SPEED COUNTER FUNCTION
Setting condition
) ( )
CH1 current value
d d
(SD1880 and SD1881)
and
) (
º
) (
<
or
) (
>
) (
=
( )
Ring counter
upper limit value
)
Ring counter
upper limit value
)
Ring counter
lower limit value
8
)
Ring counter
upper limit value
)
Ring counter
upper limit value
201