Scaling of Battery Current using FX3u32Mt and FX2N 8Adc

[praty 0]

Hello Everyone,

I am using Fx3u-32MT with extension FX2N-8AD,GOT 1000 HMi Mitsubishi.

I am  using two point scaling for scaling the battery current as follow:-

X0=0 

Y0=-80 

X1=16385 

Y1=80

 And scl function

The only problem I am facing is if I scale the battery current on HMI according to actual current meter (which is showing actual current flowing through it ) in Morning and in evening when I monitor the current in HMI and compare with actual current flow through battery are varying in large percentage.

For example Current Meterr showing 6.1A HMI showing 4.9A.

Can anybody suggest or recrecommend any alternative idea.

Thank you

[Bryll 31]

First of all, how do you measure the current ?

Are you detecting the voltage drop over a fixed resistor and calculate the current from resistor value and voltage drop ?

 

[praty 0]

I am measuring current through shunt of 0 to 75mV which is given to  

0to 100mV to 0to 10V transducer to ADC

[Bryll 31]

Let's check if I understand your setup

Your shunt will give you 75mV at maximum current flow.

Then you have a transducer that will give you 7,5 V at the 0-10V ADC input.

What resolution have you set at the ADC, 4000, 10000 or 16000 as max converted input value ?

Could you please supply a drawing how it's connected ?