Re: A bit of a math problem
number of pumps = ((discharge rate) /(individual pump capacity))+1
if the rate of change of tank level is not linear with discharge rate then use a lookup table
Re: A bit of a math problem
Thanks Richard.
My problem is to find that rate of change.
I have a sensor that gives me the level of the tank. Also a variable 'rate' that is set by the user.
Now I have to combine these two and decide how many pumps should work at a time.
Ioannis
Re: A bit of a math problem
Take measurement ever XYZ sec.
Discharge rate is First-Second.
Eg do something like this:
Code:
RunFirstTime:
ADCIN SensorValue' or whatever
OldSensorValue=SensorValue' initialization at beginning of program
return
SubRoutineToRunEveryXYZsec:
ADCIN SensorValue' or whatever
DischargeRate=OldSensorValue-SensorValue
OldSensorValue=SensorValue
RETURN
Depending on how often you call SubRoutineToRunEveryXYZsec you can get quicker response, or better resolution(wider range of values). That all depends how quick your process is.
Re: A bit of a math problem
Thanks Richard. I see what you mean.
Greet help on that small hour that my mind is almost in literary sleep mode!
Ioannis
Re: A bit of a math problem
Another approach would be:
SELECT CASE Level
CASE < 80 : HIGH Pump1 : LOW Pump2 : LOW Pump3 : LOW Pump4
CASE < 70 : HIGH Pump1 : HIGH Pump2 : LOW Pump3 : LOW Pump4
CASE < 60 : HIGH Pump1 : HIGH Pump2 : HIGH Pump3 : LOW Pump4
CASE ELSE : HIGH Pump1 : HIGH Pump2 : HIGH Pump3 : HIGH Pump4
END SELECT
Re: A bit of a math problem
Thanks mpgmike. Good one too!
Ioannis