OH3 Transform usage

I’m trying to understand what the best way is to migrate from OH2.5 to OH3. I have a question about the syntax for transform. The below is not working. What is wrong?

I’m using the below in OH2.5 and is working.
Thing data SMA_Vandaag “SMA_Input_Vandaag” [ readStart=“30535”, readValueType=“uint32”, readTransform=“JS(smalimit.js)”

(function(i) {
if(i < 0) return “0”;
return parseFloat(i) / 1000;

I assume you have installed the JS Transormation?

Are there any error’s in the log

Thanks James. Working fine now.