Vortex

The refurbished Vortex PC is able to be used as a VSI recorder with a maximum data rate of 512 Mbps (limit is set by the PCI interface speed). All of the usual evlbi recording software is installed on this PC in the ~vlbi/evlbi/ subdirectory. Vortex has a large RAID (~9.1 TB) which can be used for recording to. It is mounted as /exports/vortex_internal/. Be aware that this RAID is also used for temporary storage of IVS data for e-transfer and does not cope well with simultaneous high-speed access.

The recorder is best controlled via the command line (cdisko2.pl is available but unconfigured, and missing some perl libraries). The commands to control the recorder are summarised below.

As vlbi@vortex

~/evlbi/vsib_multi/vsib_record -t 30s -w 16 -m 2 -o GRB_Ho

SwitchUse
-tSets recording duration
-wSets bandwidth (MHz)
-mMode. 0 => 16 channels, 2=>8 channels, 3=>4 channels
-oSets base file name
-xSets rounded start
-fSets output file size. Normally, would use -f 1m or -f 1s for fringe-checking.
-rSets VSI clock rate in MHz. Defaults to 32 MHz
-cCompression mode. Cryptic syntax, but apparently able to channel-drop. Defaults to xxxx (all channels recorded)