Short description
The output is set or reset depending on two configurable thresholds (hysteresis).
Connection |
Description |
Input Ax |
Input the analog signal to be evaluated at input Ax. Use the analog inputs AI1...AI8, the analog flags AM1...AM6, the block number of a function with analog output, or the analog outputs AQ1 and AQ2. 0 - 10 V is proportional to 0 - 1000 (internal value). |
Parameter |
A: Gain B: Zero offset On: On threshold Off: Off threshold p: Number of decimals |
Output Q |
Q is set or reset depending on the set thresholds. |
Parameters On and Off
The On and Off parameters can be provided by the actual value of another already-programmed function:
Analog comparator: Ax – Ay
Analog trigger: Ax
Analog amplifier: Ax
Analog multiplexer: AQ
Analog ramp: AQ
Analog math: AQ
PI controller: AQ
Up/Down counter: Cnt
You select the required function by the block number.
|
0BA4: A: Gain Range of values 0.00...10.00 0BA2, 0BA3: These parameters apply: G: Gain in [%] Range of values 0..1,000 % O: Offset Range of values ±999 On: On threshold Off: Off threshold |
Parameter p (number of decimals)
Parameter p applies only to the display of On, Off and Ax values in a message text.
Parameter p does not apply to the comparison of On and Off values. (The compare function ignores the decimal point.)
Timing diagram
Description of the function
The function reads the value of the signal at the analog input Ax.
This value is multiplied by the value of parameter A (gain). Parameter B (offset) is added to the product, hence
(Ax * Gain) + Offset = Actual value Ax.
Output Q is set or reset depending on the set threshold values. See the following calculation rule.
|
0BA2, 0BA3: The function is as follows: The offset parameter is added to the read analog value. The sum is multiplied by the value of the gain parameter. Value = (AI+offset)*gain Output Q is set to 1 if the calculated value exceeds the on threshold (TH high). Q is reset to 0 when the value reaches or drops below the off threshold (TH low). |
Calculation rule
If threshold (On) >= threshold (Off), then:
Q = 1, if the actual value Ax > On
Q = 0, if the actual value Ax <= Off.
If threshold (On) < threshold (Off), then Q = 1, if
On <= the actual value Ax < Off.
Particular characteristics to be noted when configuring
Refer to the help on analog block parameters in the Analog value processing section.
Note
The decimal point setting must be identical in the minimum and maximum range.