A Mini-Compuiter Based Digital RF Control System for the ZGS

The systen includes a h igh-resolut ion, f ield-dependent RF frequency program generator, an optically coupled digital-to-frequency converter, and a fast-sampling frequency monitoring section. The frequency program originates as a 500 point field-indexed table of frequencies. Off-set, gain, non-linearity correct ion, and operator control are provided by software. Linear interpolation between break-points is accomplished by dedicated arithmetic logic to provide frequency updates as often as every 20?? s. An optically coupled digital-to-analog, (D-A) converter controls the 4 to 14 MHz output of the RF section. The output frequency is monitored by a fast sampling, high accuracy logic system, whose output is fed back to the computer for comparison to the desired program.