Short description
The output is set and reset depending on a configurable threshold and a differential value.
Connection |
Description |
Input Ax |
You apply the analog signal to be analyzed 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 Delta: Differential value for calculating the off parameter p: Number of decimals |
Output Q |
Q is set or reset, depending on the threshold and difference values. |
|
0BA4: A: Gain Range of values 0.00...10.00 |
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 A: Function with negative difference Delta
Timing diagram B: Function with positive difference Delta
Description of the function
The function fetches the analog signal at input Ax.
Ax is multiplied by the value of the A (gain) parameter, and the value at parameter B (offset) is added to product, i.e.
(Ax * gain) + offset = actual value of Ax.
Output Q is set or reset, depending on the set (On) threshold and difference value (Delta). The function automatically calculates the Off parameter: Off = On + Delta, whereby Delta may be positive or negative. See the calculation rule below.
Calculation rule
When you set a negative differential value Delta, the On threshold >= Off threshold, and:
Q = 1, if the actual value Ax > On
Q = 0, if the actual value Ax <= Off.
See the timing diagram A.
When you set a positive differential value Delta, the On threshold < the Off threshold, and Q = 1, if:
On <= the actual value Ax < Off.
See the timing diagram B.
Particular characteristics to be noted when configuring
Refer to the help on analog block parameters in the Information on analog value processing section.