Leigh

Unfortunately the version if Citect is usually determined by the client, unless its a completely new project. If you dont mind, throw up your cicode so we can have a look for the problem.

Also last time i checked, the PIC driver doesn't like SP3 on XP.

You could take a sample say every 15 sec (or any length of time you want,) Get the difference in weight between samples and then multiply that number by 4 (4*15sec = 60sec) Sample 1: 15kg Wait 15 sec Sample2: 12kg 15-12 = 3kg 3*4 = 12kg/min Just make sure your sample updates fast enough for your PID loop. Feel free to comment, as i haven't been doing this for very long