How to calibrate load cell using Delta PLC

Hi guys,

I am using LCSoft the calibrate load cell, the LCSoft send a specific value to PLC then i can use it and scale or calibrate in PLC Delta and showing the result in HMI.

I have to oust a two numbers the first one is the weight and the second one is the digital value.

For example: if i use 10kg weight and set the scale on LCSoft 1000 and the digital value is 1000 also so when the load cell read 10kg it will send a value of 1000 to PLC then by dividing by 100 i get the value.

If i have 125000kg load cell how to calibrate it? the same way? does it matter one word or two?

thanks,

I'm a little confused, I assume that the system you have sends data via coms to the PLC, (if it was analogue via a analogue card A/D then the max resolution would be +/- 10kg giving a max A/D count of 32767).
If the value being sent is 125000 then this probably takes up two registers i.e. longint. then the scaling would still be the same. if you convert the longint to a real (float) then you can scale in the same way as 0-10kg but with greater accuracy than using integers.
If it is coms then why do you need to scale it as a loadcell system that reads from 0-125,000 kg is the true value ? There are two reasons for scaling one for analogue cards i.e. 0-32767 where the value is a representation of the real weight, however, on coms then it would be assumed the load cell controller sends the correct weight (if scaled correctly on the LC controller).

parky said:

I'm a little confused, I assume that the system you have sends data via coms to the PLC, (if it was analogue via a analogue card A/D then the max resolution would be +/- 10kg giving a max A/D count of 32767).
If the value being sent is 125000 then this probably takes up two registers i.e. longint. then the scaling would still be the same. if you convert the longint to a real (float) then you can scale in the same way as 0-10kg but with greater accuracy than using integers.
If it is coms then why do you need to scale it as a loadcell system that reads from 0-125,000 kg is the true value ? There are two reasons for scaling one for analogue cards i.e. 0-32767 where the value is a representation of the real weight, however, on coms then it would be assumed the load cell controller sends the correct weight (if scaled correctly on the LC controller).

Click to expand...

I am using load cell module and the income value depends in how much do you to represent this weight, for example i want every 50kg send me one digital bit then i convert this digit

We really need more information. Is it into an analogue card or are you reading the values through some communication card. it makes a lot of difference as I explained before.
Give us the type of PLC, the Type of card (analogue or communication), The load cell info if possible. and the range for example 0-1500kg, is it 4-20ma or coms e.g. modbus, ethernet etc. You do not use digital bits as such. for example communication will normally be ASCII chars like 02,1,5,000,CR
or a value of between 0-32767. if on an analogue A/D card.

parky said:

We really need more information. Is it into an analogue card or are you reading the values through some communication card. it makes a lot of difference as I explained before.
Give us the type of PLC, the Type of card (analogue or communication), The load cell info if possible. and the range for example 0-1500kg, is it 4-20ma or coms e.g. modbus, ethernet etc. You do not use digital bits as such. for example communication will normally be ASCII chars like 02,1,5,000,CR
or a value of between 0-32767. if on an analogue A/D card.

Click to expand...

i am using load cell module or card, special module for load cell. it is using for calibration a LCSoft software and the software send a didital value to PLC.
i am using delta plc brand.

load cell module is DVPLC201SL-LC

Google does not recognise that part number, however there is an LCA20 type indicator, I have used these before These give out an analogue signal 4-20ma (I believe they also have other types of output and probably communication. however, assuming you are using 4-20ma or 0-10v then to calibrate the the loadcell amplifier you need to read the instructions but basically you put it into configure mode, this gives you options. I do remember when you get to CALL (Calibration low you set the value i.e. 0000 (assuming you are calibrating the low value normally 0, this takes the weight of the vessel that sits on the loadcells and by accepting this zeros the weigh indicator for example if the weigh table/vessel sits on a load cell or cells and the weight of the table/vessel was 200kg, setting zero on the CALL (Cal Low) zeros the system so 4ma = 0kg.
You then Accept, got to CALH (Calibration high), add a known load say 1500kg then set the display to 1500 and accept this then sets the 20ma level to 1500kg. providing the card on the PLC is calibrated for 4ma = 0 and 20ma = 1500 then this is the calibration done. I do not understand your comment that says the unit gives you a digital output ? what do you mean.
It may have a relay contact but that is often used for batching or over range etc.
If you need the current weight in the PLC then this is either analogue value from the analogue card or a string of characters from communications.