Instruction manual

Counters
890USE18300 September 2003 101
Counter Preset You must specify the counter preset value before implementing a counter operation.
The preset must be an unsigned integer in the range 0 to 65 535. A counting
sequence always begins at the counter preset, then increments or decrements from
there each time the count input value transitions from 0 to 1.
For example, say you have an up-counter with a preset value of 25. The counter will
start a counting sequence at 25 and will increment by 1 each time the count input
rises from 0 to 1:
If you are using a down-counter with a preset value of 25, the counter will start a
counting sequence at 25 and will decrement by 1 each time the count input rises
from 0 to 1:
26 27
28
30
inputs
0
1
29
26
27
28
29
up-counter
counter preset = 25
outputs
30
25
24
23
24 23 22 20
inputs
0
1
21
24
23
22
21
down-counter
counter preset = 25
outputs
20