# TOTAL FLOW OR TOTALIZER

## 3 posts in this topic

Hi there .. i am new to plc... i have flow rate in m3/h and i want total flow or totalizer ... what is the formula for that and how can i implement it in gx developer. any kind of help will be a life saver.

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The above thread is for Siemens but you can apply the formula.
Hope this helps you out.
Regards,
Garry

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A total flow is calculated as follows:

Q= (Vn + Vn-1)*dT/2 + Qn-1 ,

where

Qis a total flow at current measurement;
Qn-1 is a total flow at previous measurement;

- Vn is an instantaneous flow at current measurement;
- Vn-1 is an instantaneous flow at previous measurement;

- n is a number of measurment (starting from 1)

- dT is a time interval of measurements. It's a constant.

For example:

If V0= 0, V1= 0, V2= 2, V3= 4, V4= 8, V5=8, V6=4 [m3/h] and dT= 0,1s , then Q0= 0, Q1= 0, Q2= 1/36000, Q3= 1/36000 + 3/36000 = 4/36000 =1/9000, Q4= 4/36000 + 6/36000 = 10/36000 =1/3600, Q5= 10/36000 + 8/36000 = 18/36000 =1/2000, Q6= 18/36000 + 6/36000 = 24/36000 =1/1500 [m3]

Edited by Inntele