Chromatography Forum

Hi.

I`ve got a problem with setting up a elution profile at a Ultimate 3000. I want to do a multistep gradient with a curve value 8 between 4.0 and 60.0% buffer B. So i write "micropump1.curve = 8" after the 60.0% command. (Time 50.0)

But in the ready check the system tells me, that "all gradient commands must be specified at time 50.000" and "curve must be specified at time 3.0 for gradient commands"

can anybody help me? many thanks.

When you see the message "all gradient commands must be specified at time ..." you need to specify %B (%C, %D if you have them), flow rate, and curve at the time it asked for. Otherwise the time table may be ambiguous at that time. I commonly get this error on the last step of my programs because I forgot something.

If you specify a nonlinear curve (!=5) at any time, you must specify the curve at every earlier time after time zero. Just put "micropump1.curve = 5" at 3.00 minutes (and any intermediate times). Don't put a nonlinear curve command at time zero or earlier.

You may get the errors again with different times, depending on the complexity of your program. Just follow the advice repeatedly until all the errors are eliminated.

Thanks a lot. That fixed the errors...