GMVA Setups

VLBA

RDBE DDC mode with 4x128 MHz bands, dual-pol

DBBC2 Stations (Eb,On,Ys,Mh,Pv)

All DBBC2 stations should use:

• DDC mode (firmware 107 beta3)
• LO=85500
• 2nd Nyquist zone: 512 -1024 MHz
• Use 2 Core-boards

Bitstream setup:

Note: Use astro if IFs are connected to Boards A+B, use astro2 if IFs are connected to boards A+C

• Pv,On,Ef:     dbbcform=astro
• Ys,Mh:        dbbcform=astro2

DBBC3 Stations (Pv)

All DBBC3 stations:

• DDC_U mode (firmware V125)

PV setup:

• 1st LO=92100 (dictated by the DBBC2 IF requirements)
• 2nd LO= 9048 (DBBC3 GComo)
  • Use E90LI IFs (4-9GHz LSB)
  • Baseband: 0-4 GHz USB => 83052 - 87052 sky freq

Bitstream order (fixed for DDC_U mode):

• BBC1-USB, BBC1-LSB, BBC2-USB, BBC2-LSB, ...

Observations can be done with 128MHz or 64 MHz subbands (see tables below)

BBC setup  (DDC_U with 64MHz bands):

BBC setup  (DDC_U with 128MHz bands):

Bandpass shapes @64and 128 MHz

R2DBE Stations (Na, Gl)

• R2DBE stations must manually setup their systems (no vex/drudg support)
• IF setup is flexible as long as the 2GHz band includes the 86012 - 86524 MHz sub-band

KVN

• Bistream order: ?
• IF setup ?

VLBA

VLBA will use tunable mode with the following 4x128 MHz sub-bands:

DBBC3

DBBC3 stations will use DDC mode with 64/32 (TBD) MHz sub-bands.

DBBC2

DBBC2 stations will use the DDC firmware v107 yielding 16x32MHz subbands:

GLT

KVN

In this mode 32 channels of 32 MHz from the PFB will be used. 16 channels for each polarization. To avoid the complications by the tracklist in the flex mode it would be preferred to observe this part using the basic "dbbcform=spol" mode. This requires the IFs to be connected to the last two Core2Boards. As we need this for the ALMA mode below as well this should not be an issue for this test. If necessary at all stations need to recable any how.
The configuration is then quite simple:

DBBC Setup

dbbcform=spol

All data from the last Core2Board (presumably IFD) will be send to VSI1 and all from last-1 (presumably IFC) to VSI2.

Fila10G Setup

splitmode off
inputselect vsi1-2
vsi_samplerate 64000000
reset
vdif_frame 2 32 8000
reset

This will produce a joint 64 bit stream with the first 32 bits from VSI1 and the second half with 32 bits from VSI2. If the correlator prefers to have alternating channels we would also need to command the permutation matrix from below.

regwrite chan_perm 0 0x21200100
regwrite chan_perm 1 0x23220302
regwrite chan_perm 2 0x25240504
regwrite chan_perm 3 0x27260706
regwrite chan_perm 4 0x29280908
regwrite chan_perm 5 0x2B2A0B0A
regwrite chan_perm 6 0x2D2C0D0C
regwrite chan_perm 7 0x2F2E0F0E
regwrite chan_perm 8 0x31301110
regwrite chan_perm 9 0x33321312
regwrite chan_perm 10 0x35341514
regwrite chan_perm 11 0x37361716
regwrite chan_perm 12 0x39381918
regwrite chan_perm 13 0x3B3A1B1A
regwrite chan_perm 14 0x3D3C1D1C
regwrite chan_perm 15 0x3F3E1F1E
reset

After all the settings have been done, the Fila10G needs a timesync from FMSET or in case of an internal GPS a manual fila10g=timesync.

DBBC2 setup

Restart of the DBBC PFB control software is not required unless the DDC mode was used prior to the fullband mode.

The only option to be commanded is

dbbcform=full_auto

FILA10G setup

To combine the both VSI streams it is usually enough to set the Fila10G to:

splitmode off
inputselect vsi1-2
vsi_samplerate 64000000
reset keepsync
vdif_station PV        (<-change to your station code) 
vdif_frame 2 2 5000 ct=off
reset keepsync
regwrite chan_perm 0 0x21200100
regwrite chan_perm 1 0x23220302
regwrite chan_perm 2 0x25240504
regwrite chan_perm 3 0x27260706
regwrite chan_perm 4 0x29280908
regwrite chan_perm 5 0x2B2A0B0A
regwrite chan_perm 6 0x2D2C0D0C
regwrite chan_perm 7 0x2F2E0F0E
regwrite chan_perm 8 0x31301110
regwrite chan_perm 9 0x33321312
regwrite chan_perm 10 0x35341514
regwrite chan_perm 11 0x37361716
regwrite chan_perm 12 0x39381918
regwrite chan_perm 13 0x3B3A1B1A
regwrite chan_perm 14 0x3D3C1D1C
regwrite chan_perm 15 0x3F3E1F1E
reset keepsync
timesync 

Note: the last command "timesync" will only work if your FiLA10G is equipped with a GPS module/antenna. If this is not the case at your station you can do the time syncronization either:

• manually:  timesync  <YYYY>-<MM>-<DD>T<hh>:<mm>:<ss> 

• use the FS fmset command. This must be done prior to executing the above procedure!

IMPORTANT: Do not use FMSET to sync the FILA10G after executing the above procedure as this will partially overwrite the above setting.

Note: The regwrite statements will join the two steams to a single 64 bit stream one after each other VSI1 bit 0-31 and VSI2 bit 32 to 61. The correlator expects to have alternating bits from channel 1 and 2. VSI1 bit 0+1, VSI2 bit2+3, ....

The mode has been succesfully tested at Effelsberg (details).