LS Industrial Systems GLOFA G7M-DT60U(N)/DC - Page 114

Chapter 7. Usage of Various Functions
7-7
• CY (Carry) and BORR (borrow) function blocks can be reset by preset operation and HSC can re-starts its operation.
(b) Ring counter
• If HSC is designate as Ring counter, it can counts from 0 to set value.
• The carry flag turns On when the current value of high speed counter reaches set value during up counting and current
value is changed to 0.
• The borrow flag turns on when the current value of high speed counter is reaches 0 during down counting and current
value is changed to ‘set value –1’.
• When set value is out of range(2 ~ 2,147,483,647), Ring counter setting error(h’11) occurs and HSC operates as linear
counter.
• When current value is changed to out of range(2 ~ 2,147,483,647) by preset operation, Ring counter setting error(h’11)
occurs and HSC operates as linear counter.
• The ring counter setting error can be corrected by re-start of instruction(HSCST) only.
Increasing
Decreasing
Carry occurs
Borrow occurs
0
Current value
Increasing
Decreasing
Carry occurs
Borrow occurs
0
Current value
2,147,483,647
-
2,147,483,648
2,147,483,647
CY output