User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
228 Manual, 06/2014, A5E33039675
● Analog ramp (Page 216) (actual value AQ)
● PI controller (Page 220) (actual value AQ)
● Up/down counter (Page 173) (actual value Cnt)
● Analog filter (Page 232) (actual value AQ)
● Average value (Page 237) (actual value AQ)
● Max/Min (Page 234) (actual value AQ)
● On-delay (Page 136) (current time Ta)
● Off-delay (Page 140) (current time Ta)
● On-/off-delay (Page 142) (current time Ta)
● Retentive on-delay (Page 144) (current time Ta)
● Wiping relay (pulse output) (Page 146) (current time Ta)
● Edge-triggered wiping relay (Page 148) (current time Ta)
● Asynchronous pulse generator (Page 150) (current time Ta)
● Stairway lighting switch (Page 154) (current time Ta)
● Multiple function switch (Page 156) (current time Ta)
● Stopwatch (Page 171) (actual value AQ)
● Mathematic instruction (actual value AQ)
● Threshold trigger (Page 180) (actual value Fre)
Select the required function by the block number. For information on parameter defaults,
refer to the On-delay (Page 136) topic.
Note
If the analog value for parameter V1, V2, V3 or V4 is derived from another already
-
programmed function whose actual value exceeds the value range for V1 to V4, LOGO! will
display the limit value
-32768 if the value is less than the lower range or 32767 if the value is
greater than the upper range.
Parameters p (number of decimals)
Parameter p applies only to the display of Value1, Value2, Value3, Value4 and AQ in a
message text.
Functional description
The mathematic instruction function combines the four operations and three operators to
form an equation. The operator can be any one of the four standard operators: +, -, *, or /.
The priority of operators is determined by "( )" and "[ ]", in which "( )" has a higher priority.
The operand values can reference another previously-defined function to provide the value.
The mathematic instruction function rounds the result to the nearest integer value.