Chromatography Forum

Waters HPLC Alliance shows solvent ratios on monitor screen as 100%A, 0%B, 0%C, 0%D Empower on computer shows 50%A, 0%B, 0%C, 0%D. Sample sets will not run with discrepancy. Should I re-config instrument on software? How can it only add up to 50% on software???

Are you initiating running via Empower, or by using the keypad on the Alliance?

Initialization is through the Empower software.

So you tell it to pump x mL/min, 50%A, 50%B and the Alliance does so and reports doing so on the Alliance display but is fouled up in Empower...

I'm thinking that there may be a firmware issue with the Alliance. Have you recently installed anything new on the Empower server(s)?

If it was working fine until recently, and there have been no changes to the LC or Empower servers, I'd go through the cable connections very carefully, making sure they're all snug and clean.

OK I will check connections. When i tell Empower to set at 100%A it goes 100% A on alliance but 50%A on Empower.
When I tell it 75%A and 25%B in empower, it goes to 37.5%A and 12.5%B (exactly half)

No updates have been done recently to firmware or system. strange....

If checking cables is no help, try writing a new instrument method from scratch and see if that works.

If not, please post a lot more detail about your Empower setup and Alliance.

Thanks for your help. I took the instrument offline and then online again. I re-booted the alliance and now it works fine! It must be a bug when they updated the server.