Siemens LOGO!, Manual

Page: 213 / 534

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
213
4.4.18 Analog threshold trigger
Short description
The output is set and reset at two configurable thresholds.
Symbol in LOGO! Wiring Description
Input Ax Input Ax is one of the following analog signals:
• AI1 to AI8 (*)
•
AM1 to AM6 (if 0BA6) or AM1 to AM16 (if 0BA7)
• NAI1 to NAI32 (if 0BA7)
•
AQ1 to AQ2
• NAQ1 to NAQ16 (if 0BA7)
•
Block number of a function with analog output
Parameter A: Gain
Range of values: ±10.00
B: Zero offset
Range of values: ±10,000
On: On threshold
Range of values: ±20,000
Off: Off threshold
Range of values: ±20,000
p: Number of decimals
Range of values: 0, 1, 2, 3
$
4
$[
3DU
Output Q Q is set or reset by the threshold triggers.
* AI1...AI8: 0...10 V corresponds with 0...1000 (internal value).
Gain and offset parameters
Please note the information on gain and offset parameters in topic "Calculating the gain and
offset of analog values (Page 154)".
Parameters On and Off
The On and Off parameters can be provided by the actual value of another already-
programmed function. You can use the actual values of the following functions:
●
Analog comparator (Page 218) (actual value Ax – Ay)
● Analog amplifier (Page 226) (actual value Ax)
● Analog multiplexer (Page 248) (actual value AQ)
● Analog Ramp (Page 251) (actual value AQ)
● Mathematic instruction (Page 265) (actual value AQ)
● PI controller (Page 256) (actual value AQ)
● Up/down counter (Page 201) (actual value Cnt)