TwinCAT Structured Text Programing (LOOP)

Hello Everyone:

I have been able to read value via canopen interface using ADS protocol.
Actually my Structured Text Programming is weak. I can read the value only when I toogle 'Read' in the ADS. I want the READ the value automatically whenever I write a new value. But instead I have to toogle the READ everytime I write the a new value.

Can somebody send me the code in structured text of LOOP that I have to implement to READ so that it goes on automatically whenever I write a new value.

How to perform a loop on 'READ' in structured text? 'READ' is just a toogle bit. Please reply

if value != oldvalue
then oldvalue=value;
read=true
else read=false
end_if

Thanks Shooter.

Do I need to write the physical value here?

What is the value and old value here?

and yes you have to read the ADS on reguklar basis as you dont know when value is changed.

Hi Shooter. I have tried these 2 codes. But they are not working. Actually i want that whenever I write a new value the read toogle bit automatically becomes true.
In the first case scVoltage is the scaled voltage that I get after writing the value. But the read toogle bit does not go False and it remains True.

IF scVoltage>=1THEN
fbADSREAD.READ:=TRUE;
ELSE
fbADSREAD.READ:=FALSE;
END_IF

In this case whenever my write goes true my read goes true but the problem is that it reads the previous value.

IF fbADSWRITE.WRITE=TRUE
THEN
fbADSREAD.READ:=TRUE;
ELSE
fbADSREAD.READ:=FALSE;
END_IF

So what will be the code then in such a way that whenever I write a new value I automatically read the value.I dont have to toogle the bit by pressing
cntrl+f7.
Thanks
Regrds

IF scVoltage <> oldvoltage THEN
fbADSREAD.READ:=TRUE;
put here also to fill the array with the newvalues.
oldvoltage=scVoltage;
ELSE
fbADSREAD.READ:=FALSE;
END_IF