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I have pulse programs which work great on our varian INOVA instruments, but when I transfer them to varian VNMRS I get error messages and/or decreased signal. Have any of you encountered this problem? I would really appreciate any ideas of what needs to be changed in the pulse program to make it VNMRS compatible. Thank you in advance!

asked Oct 19 '11 at 14:29

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mikaelastewart
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The only significant change in going from INOVA to VNMRS (really from Sun to Linux) is that Linux requires psg_abort instead of abort. Just replace all abort statements with psg_abort and the sequences should compile. BioPack sequences work on Unity plus, INOVA and VNMRS (as well as the new DD2).

Performance should be identical, but since you are comparing different consoles it is likely that the difference lies in calibrations.

George Gray, Agilent Technologies

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answered Oct 23 '11 at 10:01

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updated Oct 23 '11 at 15:06

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Looks like the emailer or something removed the underscore in psg_abort. Replace all "abort" statements with "psg_abort". Make sure an underscore is between psg and abort. -George Gray - georgeg (Oct 23 '11 at 10:02)

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To follow up a bit on George's answer, I've had problems in the past with calibrations. In my experience, the single most important parameters to calibrate for BioPack or any other sequence that calculates pulses "on the fly", aside from having good "hard" 90 degree pulses, are the amplifier compression factors on 1H (comp/compH) and 13C (compC). If these aren't good, your shaped pulses and decoupling will be off. Also, make sure you optimize you gradient pairs if the experiments are gradient selected. A seemingly small mismatch can cause severe attenuation. I just array gzlvl2 in a range a couple hundred units to either side of gzlvl1 and pick the strongest signal. Both of these are hardware rather than software dependent.

Also, as George said, if these are your own or third party sequences, changing abort to psg_abort should let the sequence compile. There are a few other commands you should update, but I've never had a sequence not run with the old syntax. In particular, any statements involving TODEV, DODEV, etc. should be updated, e.g. rlpower(tpwr, TODEV) should be changed to obspower(tpwr).

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answered Oct 26 '11 at 07:46

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Andrew Fowler
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I traced the error message to the need for explicit blank and unblank statements for a carbon decoupling pulse. The pulse sequences would compile and run but returned an error message when ran. The signal to noise issue was likely a hardware issue related to 2H decoupling that I found with George's help. Thank you for your answers.

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answered Nov 02 '11 at 08:15

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mikaelastewart
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