User's Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
210 Manual, 04/2011, A5E03556174-01
4.4.17 Threshold trigger
Short description
The output is set and reset with two configurable threshold triggers.
Symbol in LOGO! Wiring Description
Input Fre The function counts the 0 to 1 transitions at input Fre.
1 to 0 transitions are not counted.
Use
• inputs I3, I4, I5, I6 for fast counting (only LOGO!
12/24RC/RCo, LOGO! 12/24RCE, LOGO! 24/24o
and LOGO! 24C/24Co): max. 5 kHz, if the fast
input is directly connected to the threshold trigger
function block
• any other input or circuit component for counting
low frequency signals (typ. 4 Hz).
Parameter On: On threshold
Range of values:
0000...9999
Off: Off threshold
Range of values:
0000...9999
G_T: Time interval or gate time during which the input
pulses are measured.
Range of values:
00:00 s...99:99 s
4
)UH
3DU
Output Q Q is set and reset at the thresholds.
Parameter G_T
The gate time G_T 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 threshold trigger (Page 213) (actual value Ax)
●
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)