We deployed the DAC1955 v3r3 firmware on the 3 DAC1955 boards used  for the SDB2 bench local controls

• SBE: DAC1955_SN22 located in the DBOX_SN27-slot2 and managed by the SDB_EDB_dbox_rack server 
• LC: 
  • LVDT_in: DAC1955_SN69 located in the DBOX_SN106-slot2 and managed by the SDB2_dbox_bench server
  • LVDT_out:  DAC1955_SN19 located in the DBOX_SN28-slot3 qand managed by the  SDB_EDB_dbox_rack server 
• these DAC1955 boards are now running at 400KHz instead of 100KHz with new facilties for the channel management (see  DaqBox DAC1955 documentation for the details ). The DAC1955 anti-image filter is  a 3rd order with a FCut at 20KHz

The related DBox servers have been updated with the v17r9  the 2026-05-13 and then with v17r10 release the 2026-05-15

These plots show the trend of the relevant signals from the 2026-05-10 to the 2026-05-21 for

•  SBE_SDB2  x,y,z and act1,act2,act3,act4  channels
•  SDB2_LC txyz and txyz_corr channels 

The operations have been done over 1 week, from the 2026-05-12 to the 2026-05-20 

• 2026-05-12-09h57m47-UTC  to 2026-05-12-15h33m36-UTC 

  • DAC1955 v3r3 firmware installation on the related DAC1955 mezzanines
  • Use DBox server  v17r9  release for SDB_EDB_dbox_rack and SDB2_dbox_bench servers
  • the DAC1955 data reception  was set in asynchronous mode and the data policy extension is set to use the zero policy for this version of the DBox server
  • SDB2_SBE and SDB2_LC configuration files update 
    • for SBE and  LC_LVDT_out , the DAC1955 channels are built at 10KHz
    • for the LC_LVDT_in  the DAC1955 channels are built at 50KHz
  • During the operations , we faced with some issues due to the DBOX server compatibility. As consequence all the DBoxes managed by the SDB_EDB_dbox_rack and SDB2_dbox_bench servers were reconfigured.
  • At the end the SDB2_LC loops were successfully closed and the SDB2_SBE ones too with the tracking disabled
• 2026-05-15-04h53m01-UTC to 2026-05-15-05h37m55-UTC
  • Looking at the FFT of LVDT_in and LVDT_out channels; one can see a new line around 36Hz  only on most of the LVDT_out channels  and the presence of the 10KHz line on all the LVDT_out channels
  • This line come from the beating of the FL_H-BR-V line at 9964.3Hz and the 10KHz line due the use of the zero extension policy.
  • Today one way to fix this issue, was to generate the LVDT_out at 50KHz ( LVDTs plots 0Hz-1KHz, 9.6KHz-10KHz ) :
    • SDB2_LC configuration updated to build the LVDT_out DAC channels at 50KHz 
    • LVDT_out DAC1955 reconfiguration to use the new TolmPacket 
  • To avoid the same issue for the SBE DAC channels, they are build at 50KHz too
  • At the end the SDB2_LC loops were successfully closed and the SDB2_SBE ones too with the tracking enabled this time,as it s the default
• 2026-05-20-07h18m46-UTC  to 2026-05-20-08h39m34-UTC
  • Enable the use of the synchronous mode for  the 3 DAC1955 used for the SDB2 SBE and LC control loops
  • the related parts of the DBox servers, SDB_EDB_dbox_rack and SDB2_dbox_bench, have been updated  by adding for the  DBOX_DAC1955_INPUT_PACKET keyword  "sync" and a "delay value" measured using the command /virgoApp/DaqBox/v17r10/Linux-x86_64-CL7-4.14.111-hal-3-rtai-5.2/DaqBoxCtl.exe -s -m   -e 
  • After these operations,  the SDB2_LC loops were successfully closed and the SDB2_SBE ones too with the tracking enable

Note: the DAC1955 synchronous mode has been deployed  to NCAL NE and WE   DAC1955 boards too :

• WEB NCAL: operations performed between  2026-05-20-09h15m36-UTC and 2026-05-20-09h31m13-UTC, the phase loops were successfully closed after these modifications
• NEB NCAL: operatios performed between 2026-05-20-18h38m05-UTC and 2026-05-20-18h45m18-UTC