Rockwell Automation 1746-HSCE2 Multi-Channel High Speed Counter Module - Manual (Page 107)

Publication 1746-UM002B-EN-P - August 2004
Application Examples 6-15
5. The example assumes that the controller control block is in the
HSCE2 output image when the soft preset is implemented.
Additional logic (for example, preset change latch XIO from
example 5) is needed to delay the soft preset logic if other
ladder logic changes the output image. (For example, example 5
dynamically changes the preset values and temporarily puts the
min/max count value block in the output image.)
6. Rung 3 unlatches the HSCE2 Counter 1 soft preset bit (O:1.1/1)
when the soft preset is completed. Since the Counter 1 count
value may be changing, we have created a count range using
the preset value (N10:25*1000 + N10:26) ± 10 counts to
determine if the soft preset is within range. If the Counter 1
count value is static during the soft preset, the ladder logic could
simply compare the Counter 1 count value with the preset value.