MAN0974-09-EN_XL7_UserManual
March 4
th
, 2019
Page 93 | 185
12.3.8 Status Bits
There are three status bits (%I registers for each high-speed counter).
Overflow Flag: This status bit turns high when the
Accumulator “overflows”, it moves from
4,294,967,295 (-
1 if Signed) to 0, this bit can be reset with the “Output Reset Bit”. See Table
11.4.
Underflow Flag
: This status bit turns high when the Accumulator “underflows”, it moves from
0 to 4,294,967,295 (-1
if Signed), this bit can also be reset with the “Output Reset Bit”.
NOTE: For the Overflow and Underflow flag registers, if using some sort of counter that
counts both up and down, going over the threshold to go negative, triggers the underflow, and
then going back over the threshold back into positive numbers will trigger the positive
register to go active.
High Speed Out: This register will follow the high-speed output assigned to the counter, it is
important to note that this register is still populated within the scan time so the value in this
register may not be up to date depending on the timing of the output (it should be up to date
within one scan).
