TAPESYNC is an obsolete parameter left over from the tape era.
TAPESYNC requests that SCHED try to synchronize tape changes at the stations. This is advisable to avoid slightly staggered tape changes that would naturally result from a subarrayed schedule. Such staggered tape changes can result in lost data because there is a minimum of about 3 minutes per correlator job and a new job is needed when a station changes tape. This is a temporary restriction but was in effect in late 1996.
WARNING: TAPESYNC could cause very strange behavior if used with a schedule in which some stations are being scheduled separately from others. It should only be used when the scans as specified to SCHED are in roughly time order (for subarrays, there can be small deviations from time order and that will be ok). It is only recommended for use in conjunction with the optimization options. For any schedules in which every scan is specified in the input, it would be best to use TAPE to force the tape changes at reasonable times, if necessary.
Also, be sure that any automatically generated tape change requests occur at times with sufficient gaps at single tape stations (all except the VLBA and VLA). See the discussion of TAPE for details.
Note that, with automatic tape allocation, SCHED does not set the tape change times so TAPESYNC will have no effect.