UTAS Radio Astronomy Group | Main / VLBI Observing Using the DBBC Amp Mark 5 C

You must first power up the DBBC, Mark5C and Glapper using the Internet power switch (ipscd.phys.utas.edu.au).

After booting, log in first to the DBBC with vncviewer dbbccd:0 and start the python SerialServer program and then DBBC Control program DBBC2 ControlDDB v104_2.exe, allowing it to configure itself as per usual.

Set up the IFs, frequencies and bandwidths as per usual (issue setup01 or setup02 command in pcfs) and run pps_sync

Check the clkoff reading of the DBBC with the FS command dbbcdelay and also run maserdelay. These two should give similar results (differ by approximately 0.1 - 0.2 microseconds). If they differ by more than that you should restart the DBBC control program on dbbccd

Run fila10g_double.bat [in C:\DBBC\bin\] to set up the Fila10G with appropriate network settings, etc. To communicate with the Fila10G, use PuTTY. Check that the time is correct - you may have to set it manually as the default procedure is usually out by a few [integer] seconds. This can be fixed at the correlator but it’s far better to fix it at the beginning. To see the current time, use tick in the PuTTY terminal to see the current time printed out ~once per second. I think it’s the RTC time that should be sync’d up to the GPS tick.

You can now start up with the mark5C. Make sure that the modules have been conditioned in the mark5C before starting the recording softwar (using SSERase).

Start drs -m0 and then in a separate terminal, run ./Mark5C.Init.sh@@ to set the personality, MAC lists etc. You’ll be prompted to erase the disks - appending recordings does work though (sometimes).

To start a recording, using the drs_client to send the command record=on:scan_name:experiment:station (or use nc on port 2620 and add a semicolon at the end of the line). NB - neither scan_check nor disk2file works and will crash the mark5C if attempted. The only way of accessing the data is via fuseMk5.

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DBBCCD - 2 Gbps PFB mode

Start DBBC Control PFB v14.exe and allow it to configure itself.

Select IFs as needed

To record the PFB output of IFA, choose dbbcform=spol. To record IFB, choose dbbcform=copy. This is because the VSI input to the Fila10G is from VSI2

Set threshold=on

Notes: In PFB mode one channel is always NBG as the bandpass folds the −16→+16 MHz data over.

If using filter 1 [512–1024] note that all all channels are LSB. For filter 2 [0–512] or 3 [1024–1536] all channels are USB

If recording to Mark5B, remember to set the clock rate to 64 MHz with clock_set=64:ext:64