Instruction manual

Unsigned Compares
78
890USE18300 September 2003
Threshold and ∆ You need to enter two values—threshold and the ∆. The threshold is the value
against which the operational input is compared. You can also add a ∆ value to the
threshold, which acts as an hysteresis.
For example, say you assign a threshold value of 48,000 to the comparison action.
You then assign a ∆ value of 32 to that threshold. Thus, if your operational input
value is less than or equal to TH - ∆ (47 968), the output is 0. If your operational input
is greater than TH + ∆ (48 032), the output is 1:
While the input value is within the 2∆ band, it holds its last value.
For example, if the input value is increasing from a value less than or equal to
47 068, the output will be 0. When it exceeds 48 032, the output rises to 1. If the
input value then begins to decrease after the output has risen to 1, the output will
remain at 1 until the input value decreases to 47 968, at which point it will drop to 0.
Note: To be valid, TH + ∆ and TH - ∆ must be integers in the range 0 to 65 535.
48 000 (threshold)
input value
1
0
0
65 535
output
48 032
input value
1
0
065535
output
47 968