Non-Linear Sampling on Varian Spectrometers
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This Varian part is not fully tested! 
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The pulse sequences were tested on a Varian Inova500 spectrometer.

Necessary files

1) modified form of the protein pack pulse sequence eg nl_ghncn.c 

2) nl_setup and setnl2d macros in the maclib

3) sampling schedule

 
One could calibrate the pulses (pw, pwN, pwC, compH, compN and compC) and update the probe file using the Manage probe file option in bio pack. Then for example one wants to run a non-linear  hnca this is the sequence of steps. Type them in the vnmr window.

 
1) type ghncn (this should load the library hncn pulse program with the appropriate pulse widths and parameters)

2) type nl_setup. This should create the necessary variables needed for the setnl2d macro

3) type setnl2d("sechdule_name"). Make sure you are executing this command from the directory you have the file "schedule_name". This should create the appropriate arrays.

4) Change the seqfil to the nonlinear version by typing seqfil="nl_ghNcocaNH". THIS IS REALLY IMPORNTANT.

5) Type phase = 1,2 and phase2 = 1,2 in that order. Leave the ni and ni2 at 1. If you type da at this point the size of the array should be 4*(no of points in your sechdule).

6) Choose the appropriate nt and sws.

7) The total evolution time in each dimension is given by the dwell time * max point in that dimension. For experiments with constant time evolution in the Nitrogen dimension, make sure that sw is large enough to accommodate the maximum no of Nitrogen dimension points (the limit is that dw*max < constant time delay, where max is the largest entry in the sampling scheme for the nitrogen dimension)

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Note: the Varian pulse programs and "setnl2d" macro have been updated since Aug 22, 2005.
(This only affects the old parameter sets when using the new pulse programs. 
A new (t1_counter, t2_counter) array must be set up using the new macro.)