Acquisition Loops and Data Storage

Loops and acquisition commands are often related. Two typical applications of loops are the execution of a time averaging experiment and the measurement of a series of spectra to generate a two dimensional matrix during a 2D experiment. Both examples implement data acquisition and data storage in a specific way. The acquisition commands used in NMR-SIM pulse programs have to be structured to be consistent with the pulse programs used on BRUKER NMR spectrometers. 

In contrast to a ID experiment, at the beginning of a 2D experiment a serial file containing a fixed number of blank FID data files is generated in persistent memory. The two dimensional matrix consists of tdl files, with a size of TD with each file corresponding to one time increment in the 2D matrix. A pointer is used to instruct the computer to transfer the accumulated data for each time increment from temporary memory to the correct persistent file. The pointer is then incremented for the next element. This whole procedure is executed by the pointer command if 0. The zd command occurs after the if 0 command and deletes the buffer contents. The 2D loop is closed by the command lo to label. In this instance label is a number or a string that is entered in the first position of the line where the next time increment in the 2D matrix will be started. 

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