A. Acquire a 1-dimensional spectrum of the sample. Fourier transform and phase the data. From this spectrum determine the value of O1 and SW that will include all the peaks with the minimum acceptable spectral width. This is most easily done using the EP subroutine and CTRL O which will set SW and O1 to acquire data in the region currently displayed. Acquire a 1-D spectrum based on these values for SW and O1. Fourier transform and phase the data and set the reference. Note the value of SR after the reference has been properly set. Set CY=MAXY=any reasonable value. Store this spectrum using WR filename return. This file will contain the data just acquired plus all 1-dimensional acquisition and processing parameters. If the 2-D experiment to be performed is heteronuclear, e.g. proton carbon shift correlation, switch to another job and repeat this process with the other nucleus involved in the experiment. The rest of the 2-D set-up will be in the job that contains the spectrum of the nucleus to be observed directly.

B. Set SI to obtain as crude a digital resolution as will be acceptable to obtain the information you need. The digital resolution is the number of Hz/pt and is displayed in the first parameter block past the data when the right arrow is pressed. Setting the digital resolution to be too fine will vastly increase the amount of spectrometer time required to obtain the data. For a fast COSY of an organic compound, 6-10 Hz/pt is adequate.

C. Next set the parameters NE, ND0, and MC2. Guidance for setting these parameters is given in the comments of all microprograms. If MC2 is not mentioned in the comments, the default value of M is to be used. It is strongly advised that you have a hard copy of your own of the microprogram that you plan to use. Make sure the printer is on and type the command TYPE followed by a return. When input is requested, type the name of the microprogram to be used.

D. You !!MUST!! have set appropriate values for SW, O1, SI, NE, ND0, and MC2 before proceeding any further. (If later in your acquisition set-up you decide to change one of these parameters, you must come back to this step and start over.) Once these parameters are set properly, type ST2D to set up the DEFAULT 2-D parameter block. Next, set I2D or SW1. These parameters are not independent; changing one will change the other. Set I2D for homonuclear experiments; set SW1 for heteronuclear experiments. Guidance for reasonable values will be given in the comments of the microprogram that you plan to use.

E. For a heteronuclear 2-D data set, O2 must be set to the value for O1 used to obtain the proton 1-D spectrum stored above. This is because the proton irradiation is obtained via the decoupler channel in the 2-D experiment. The decoupler power, DP or one of the Sn parameters depending on the microprogram, must also be set appropriately. Note the digital resolution (i.e. Hz/pt) in the F1 dimension. If it is finer than required, spectrometer time will be wasted.

F. It is convenient to set a few 2-D processing parameters and store the 2-D parameter block at this point. For homonuclear experiments, set SR=SR1=SR2. Ignore the messages about not being an SMX file. For heteronuclear experiments, set SF1=frequency of the F1 dimension (usually the 1H frequency), O11=O2, SR2=SR in the X-nucleus 1-D spectrum, and SR1=SR in the proton 1-D spectrum. (It appears to be necessary to set O11 prior to setting SR1.) If you know what apodization parameters you plan to use for processing, you may set them now. Store the 2-D parameters using the command WJ2D filename return. If you do not store the 2-D parameters at this time, you will have to go back to ST2D at the time of processing. Particularly in the case of heteronuclear experiments, you will find that you will have to reset a number of parameters that you thought you had already set. It is a good idea to get in the habit of storing this 2-D parameter block at the time of acquisition to avoid later confusion and enormous quantities of wasted time and effort.

G. Next set the values of pulses, delays, etc. that are unique to the fact that you are going to acquire the data using a microprogram. It is assumed that you know the values for the pulses you need for the particular microprogram, e.g. 90 degree pulses, etc. If not, you must either determine them before you start, or if you have tuned the probe properly, the values given in the notebook will be at least reasonable for samples in organic solvents. Type AS microprogram name return. This will put the text of the microprogram on the CRT. In some cases it will stop and require that you input returns to finish displaying all the text. Once the text is finished, all parameters that are unique to the microprogram will be output for change or confirmation. The microprogram comments will give guidance in the setting of these parameters. If you make any mistakes during this part of the setup, it is a good idea to repeat the entire pass through the AS routine until you have confirmed that all parameters are correct.

H. Consider the value of NS. The time required for acquisition of the entire 2-D data set will be determined by NE times the time required for experiment (i.e. the acquisition of each summed free induction decay). There will be a minimum number of scans that will be required to obtain at least the crudest phase cycling necessary to obtain the 2-D data for a given type of experiment. If more scans are needed due to the small quantity of sample, you will be wasting spectrometer time if you could fairly readily use more sample. This decision will of course be determined by the chemistry but you should not forget to consider the possibility of making a more concentrated sample if possible.

I. The command EXPT may be used to determine the amount of time that a given experiment will require for acquisition. It doesn't take into account any loops that are due to VC lists in the microprogram.

J. Alternatively, if you have previously stored a 2-D data set and a 2-D parameter file and you expect to use the same acquisition parameters as for this previous experiment, you can read in all parameters with the following set of commands (where the file names of this example are as defined in section II A below):

K. The receiver gain must still be set. This can be done by running a microprogram that is exactly like the one you plan to use except that the GO command has been replaced by RGA and the writing of files and looping for multiple acquisitions have been commented out. Some "RGA" microprograms are available on the disk. Run a microprogram with RGA by typing AU microprogram name return.

L. Finally, start the 2-D acquisition by typing AU microprogram name return using the name of the original microprogram containing the GO command. For the case of COSY, the sequence of microprograms to be used in steps G., K., and L. is:

M. The filename where the 2-D raw data will be stored will be requested at the start of acquisition. It must have the extension .SER. The data system checks that adequate disk space is available after acquisition of the first experiment of the series is complete. If adequate disk space is not available when the first data set is stored, an error message will be output. If you plan to leave the spectrometer while the 2D data set is acquired, make sure that you stay until this first experiment is stored or you may be disappointed upon your return.

N. Data acquisition may be terminated prematurely, i.e. prior to the completion of NE experiments. In this case, you must determine how many experiments were completed. This number is essential to proper processing. If you plan to symmetrize the transformed data, do not terminate the acquisition prior to completion of at least half the number of experiments set with NE.

A. Processing data where all steps described under ACQUISITION above were completed correctly requires the following steps where it is assumed that the raw 2-dimensional data were stored in the file "RAW2D.SER", the 2-dimensional parameters were stored in "PAR2D.001", and the transformed 1-dimensional spectra to be used for projections were stored in the files "PROJ1.001" (F1 dimension) and "PROJ2.001" (F2 dimension).

B. The transformed data may be viewed in contour by typing AP2D return. Use the + and - buttons to the left of the keyboard to set the level of the contours to remove unnecessary noise, yet display the peaks of interest. To obtain an expansion of a region of the contour, type L and a box will appear on the screen which may be moved around with the knobs. Type X to make that box full scale on the display. Type ESC X (ESC followed by X, not simultaneously typed) to exit from AP2D. The level and limits of the display at the time you exit from AP2D will be used for the contour plot.

C. Type DPO to set the plotter options. Note that this is where you set the tick marks for the Y-axis. Usually you will want to set the offset = 0. Set CX and CY to appropriate values. Start the plot of the contour with projections on both axes with CP2P return. The names of the files containing the spectra to be used for the projections will be requested. (For homonuclear experiments, the projection filename is the same for both dimensions.)

D. If you want to simply replot or expand a contour plot and the file RAW2D.SMX is already on the disk from previous processing, read in all the data, 1-D, and 2-D parameters with the following sequence:

E. Processing when not all steps described in the ACQUISITION section were completed:

F. If you do not plan to archive the data, delete all the files associated with this data, i.e. RAW2D.SER, RAW2D.SMX (created by XFB), RAW2D.SMX0 (created by AP2D if you displayed the contour plot), RAW2D.SMX1 (created by AP2D if you displayed an expanded contour plot), PAR2D.001, PROJ1.001, and PROJ2.001.

A. It is not necessary to archive the .SMX file. If an appropriate 2-D parameter file is stored with the .SER file, the transformed data can be readily obtained as in step A. under PROCESSING above. If you changed any 2-D parameters during your processing (e.g. apodization parameters, tick marks on the Y-axis, etc.), you can re-write the 2-D parameter file with those new parameters with WJ2D PAR2D.001. If you did not store a 2-D parameter file at the time of acquisition, do so now with the WJ2D command. Make sure you do this from the job where you were doing the 2-D processing and that you have not read in any other data or parameters in this job since then. Delete RAW2D.SMX, RAW2D.SMX0, and RAW2D.SMX1 from the disk.

B. If there were 1-D parameters that you changed while processing (e.g. tick marks on the X-axis, offset, etc.), you can store them in the .SER file now while you have them in mind with the following sequence:

C. Transfer the data to be archived to tape on the VAX via Ethernet and delete the files from the disk as soon as possible since 2-D data sets use a fair amount of disk space.