Mitsubishi NZ2GFCF-D62PD2, User Manual

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97
CHAPTER 8 FUNCTIONS
8
8.2 C
ounter F
ormat Selectio
n
8.2.2 R
ing
counte
r functio
n
8.2.2
Ring counter function
(1) Operation of the ring counter
When "1: Ring Counter" is selected for "CH  Counter format", pulses are counted repeatedly within the range
between CH  Ring counter lower limit value (RWw10 to RWw11, RWw28 to RWw29) and CH  Ring counter
upper limit value (RWw12 to RWw13, RWw2A to RWw2B) specified by the user.
The overflow and underflow errors do not occur under the ring counter function.
The preset/replace function and the comparison output function can be used together under the ring counter
function as well as under the linear counter function.
The following figure shows the relationship among CH
 Present value (RWr10 to RWr11, RWr28 to RWr29),
CH  Ring counter lower limit value (RWw10 to RWw11, RWw28 to RWw29), and CH  Ring counter upper limit
value (RWw12 to RWw13, RWw2A to RWw2B).
No. Description
1)
When CH  Present value (RWr10 to RWr11, RWr28 to RWr29) is counted up from "CH  Ring counter upper limit value (RWw12
to RWw13, RWw2A to RWw2B) - 1", CH  Ring counter lower limit value (RWw10 to RWw11, RWw28 to RWw29) is stored in CH 
Present value (RWr10 to RWr11, RWr28 to RWr29).
2) Count-up pulse input is changed to count-down pulse input.
3)
When CH  Present value (RWr10 to RWr11, RWr28 to RWr29) is counted down from CH  Ring counter lower limit value (RWw10
to RWw11, RWw28 to RWw29), "CH  Ring counter upper limit value (RWw12 to RWw13, RWw2A to RWw2B) - 1" is stored in
CH  Present value (RWr10 to RWr11, RWr28 to RWr29).
CH Present value
(RWr10 to RWr11,
RWr28 to RWr29)
CH Ring counter
upper limit value
(RWw12 to RWw13,
RWw2A to RWw2B)
CH Ring counter
lower limit value
(RWw10 to RWw11,
RWw28 to RWw29)
+2147483647
-2147483648
0
1) 3)
2)