Concepts to Compare analog values

Hello all,

to compare constant values (with amount smaller 19999) with an analog value are neededneeded again and again and can be carried out efficient by means of a block Of "analogous threshold trigger". In the following one my generally applicable variants for the testing of analog values Ax concerning a fixed comparative value of n (for example also n = 0):

For example the block "analogous threshold trigger" with following block parameters is suitable for that...

a) Ax = n, that is the digital output Q of the threshold value countercounter is supposed to be withwith appropriate relation "= ON". Set block parameters as follows: GAIN = 1,0; OFFSET = 0; Threshold values: ON = n; OFF = n + 1
Example n = 0: ON = 0; OFF = 1; then ON Q = is if Ax = 0 is.

B) Ax > n, that is the digital output Q of the threshold value countercounter is supposed to be withwith appropriate relation "= ON". Set block parameters as follows: GAIN = 1,0; OFFSET = 0; Threshold values: ON = OFF = n
Example n = 0: ON = 0; OFF = 0; then ON Q = is, when Ax is > 0.
This is therefore the test onto positive numbers Ax.

C) Ax < n, that is the digital output Q of the threshold value countercounter is supposed to be withwith appropriate relation "= ON". Set block parameters as follows: GAIN = -1,0; OFFSET = 0; Threshold values: ON = OFF = -n
Example n = 0: GAIN = -1,0; ON = 0; OFF = 0; then ON Q = is, when Ax is < 0.
This is therefore the test onto negative numbers Ax.

D) Ax >= n, that is the digital output Q of the threshold value countercounter is supposed to be withwith appropriate relation "= ON". Set block parameters as follows: GAIN = 1,0; OFFSET = 0; Threshold values: ON = n; OFF = n - 1
Example n = 2: ON = 2; OFF = 3; then ON Q = is if Ax >= 2 is.

E) Ax =< n, that is the digital output Q of the threshold value countercounter is supposed to be withwith appropriate relation "= ON". Set block parameters as follows: GAIN = -1,0; OFFSET = 0; Threshold values: ON = -n; OFF = -n - 1
Example n = 2: GAIN = -1,0; ON = -2; OFF = -3; then ON Q = is if Ax =< 2 is.

In the same way "Analog threshold trigger" can be checked with the block, whether an analog value within aconstant k of "ON" = k1 - 1 to k2 = "OFF" (with "ON" < "OFF") to contain is Ax inside this fild or not (to use inverted block output for that), "ON", to have to lie "OFF" in the range of -20000 to 20000. At values n, k1, k2 outside of the this range must be used however for the comparison a block "comparator" (or two), in analog mode to the comparison of two analog values...

A comparison of two analog values with each other is under following link described:

With LOGO! how can you compare 2 analog values with each other?

I enlarged this basic circuit for the general applicationapplication and put explanations about suitable parameters on this basic circuit. Have a look at the circuitcircuit "DEMO_Groessenvergleich_von_zwei_Analogwerten.lsc" for this purpose in the file attachment.

Best regards
Betel