All of the VLA parameters are, at temporarily, out of use. The old VLA system has been turned off and the EVLA is not yet doing VLBI. The control scheme may change with the EVLA.
VLAINTEG is used to set non-standard integration times in VLA schedules. This would be useful mainly to influence the speed with which the system phases up. The argument is in seconds. The default is 10 seconds. SCHED generates //DS cards for all scans after a VLAINTEG is specified.