This is an eVLBI control parameter. Be warned: eVLBI support is under development. The eVLBI parameters are GRABTO, GRABTIME, GRABGAP, and DATAPATH.
GRABTIME determines which part of a scan will be used for eVLBI. There are 2 arguments. The first gives the duration in seconds of the data to be sent. The second argument gives the seconds before the end of the current scan that the grabbed data will end. Thus the data to be sent are from the interval from GRABTIME(1) + GRABTIME(2) to GRABTIME(2) seconds before the end of the scan.