PCEVN's adventures in Oz

1
PC-EVN's adventures in Oz
Woof Woof
2
Cables connection is everything
Cabling options available with the current systems
Could it be more boring? And covered yesterday
All sites have a DAS and a S2 recorder, so what
can we achieve?

• In parallel with the S2
• With two DAS's, S2-like
• At maximum rate
• With two DAS's, flat stick

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Fringe checker i.e. Addition to the S2
DATA in on the C1 port. Formated DATA out on the
C2a port. BUT it is mangled into a Mk3-ish
pin order. We have a cable which will fix this.
Bpass recorded off the C2a using BG2
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To Titan Toto!
5
Give me everything!
Now called BG3
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Plenty of mouth any trousers?
I.e. does it work?
Bpass recorded off the CORR using BG3
Bpass recorded off the C2a using BG2 during S2
record
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But does it REALLY work
But does it work at Parkes?
Write time to XRAID disks time dd if/dev/zero
of/export/xraid1/me bs8196k count77 0.010u
1.790s 006.57
Write time to NFS XRAID disks time dd
if/dev/zero of/import/cpsr2/me bs1024k
count610 0.010u 1.410s 009.02
Can do ½ Gbs with the current setup BUT there was
the occasional hiccup 1 Gbs is going to be harder
Xraid0 8.6 /-0.4 CPSR1 10 /-0.3 Xraid1
22.4/-7
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Does it really really work?
But does it work at Parkes?

• The killer test Cross correlation between CPSR2
  PC-EVN
• However Cables are only just finished (100!
  10158).
• In the mean time we have done some speed tests.
• Tests with wr across the network
• write local, copy via NFS Usually works, but
  not reliable
• write local, copy via ???
• write via NFS Usually works,
  but there are issues

Interestingly the data lost seems to be whole
seconds What to do? Other copies with less
overhead? Network off the PCI? The new nforce3
250 chipset (MSI K8)?
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PC-EVN's adventures in Oz

• Record S2 data off the S2 formatter. I.e. Fringe
  check
• Replace the S2 on the S2 connector (limited to 8
  BS or 4x 16)
• Can, if we wish record 2x 32 (still on 8 BS).

• Using the Hygens cable ( 2 DAS) we can record
  MkV like 8x16.

By replacing the S2 connector with two

• Using the Trinity cable, we can record the
  entire input to the DAS.

BUT

• We have reached the DATA limit of the PC-EVN
  the DAS

• Can we be more sophisticated? 8X16 Mhz?
  Only inside the DAS input kind of pointless

Time for a new system the FPGA poly-wolly-watizit
10
Give me more!
From Ferris et al URSI 2002
2 Ghz
4096 Channels
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PC-EVN's adventures in Oz

• Fringe Checker
• XF or FX mode ( correlate then rotate or vice
  versa)
• Japanese version of CALC (which works under
  Linux) or ATELIB
• FITs or RPF output? Only if it is taken forward.

Needs access to the data to be tested. Also
checks the data quality at the station Bpass,
1PPS, stats
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PC-EVN's adventures elsewhere
Fringe checker maybe used on the narrow band
K5 system.
If I can get a FITS writer working. Budget
application for another set of PC-EVN cards a
new MB to see if I can get the speed