Xylem System 5000 User Manual - Manual (Page 28)

MANAGING TASKS
26
log(x) Log base 10 of x, LOG(1000) = 3.0
ln(x) Natural log of x, LN(1000) = 6.90775
exp(x) Natural log base of 2.718282 raised to the power of x,
EXP(3) = 20.08554
Logarithmic Functions
abs(x) Absolute value of x, ABS(-55.67) = 55.67
sqrt(x) Square root of x, SQRT(100) = 10.0
Basic Math Functions
if(x,y,z) If condition x is true then return y else return z
IF(Batt>12.5,10,-10) = 10.0 if Batt is greater than 12.5
= -10.0 if Batt is less than 12.5
Logical Functions
When a sensor is used in several applications it may be easier to build an equation into the
operating system for that sensor rather than have customers enter the equation every time
the sensor is used. The following temperature equations are for thermistor based temperature
probes. When using one of these temperature probes see the app note for its full details.
Built In Specific Sensor Functions
Convert the voltage on analog channel X (specified in Task AnalogX) from the H-377 thermistor
probe to temperature in degrees Celsius. The following is the actual equation used:
h377c (AnalogX)
Convert the voltage on analog channel X (specified in Task AnalogX) from the H-377
thermistor probe to temperature in degrees Celsius. This function uses the same equation as
the function above, but uses the following conversion from degrees C to degrees F:
h377f (AnalogX)
Convert the voltage on analog channel X (specified in Task AnalogX) to a temperature based
on the built in voltage to temperature equation TP20B. The following is the actual equation:
tp20b (AnalogX)