Acquire or re-acquire a configured field. Fiducial objects defined in the  configuration file <field>.CFG are used with the mobile autoguider probe to calculate the field shift and rotation to be applied to the telescope to optimise the accuracy of the projected fibre placement on the sky.  AFACQUIRE advises the maximum number of fiducial objects available for acquisition. The user supplies the autoguider integration time, the number of centroids to be made for each fiducial object and the number fiducial objects to be used for acquisition. Users may choose any number of objects to be used in the measurement, subject to the minimum needed  for the fit (using SLA_FITXY) and the maximum number available.