There are two steps to setting up the DBBC - the first is the working out which IFs are needed and then setting the channels appropriately. The setups below list the most common setups and how to get them working. Specific examples from previous experiments are shown where possible. These should work for 16 MHz bandwidth observations with either 4 or 8 channels. Anything different from this needs much more work…

In general though, DRUDG should have calculated the IF frequencies correctly. You can check by comparing the with the frequencies on the LBA wiki and using LOs of 1900 MHz for S-band and 8600 MHz for X-band.

See these notes on how signals are routed through a DBBC for some background info before reading further.

As an example, here's how V252ai has it's frequencies set up according to the LBA wiki:

Running drudg on the VEX file produces the following IF setup for Ke:

define  ifd01         00000000000x            
ifa=1,agc,1
ifb=4,agc,1
lo=
lo=loa,7600.00,usb,rcp,off
lo=lob,7600.00,usb,rcp,off
enddef

define  dbbc01d       00000000000x            
bbc02=809.00,a,16.00
bbc04=825.00,a,16.00
bbc06=841.00,b,16.00
bbc08=857.00,b,16.00
enddef

dbbc01d and ifd01 procedures to get the input bands, BBC channels etc configured correctly.

Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-7600). Using v271k as an example, channel 1's lower band edge is 8200 MHz. The first line in the @@dbbc_config_file_v271k.txt@@ is then @@1 dbbc2.bit 600.00 16@@. Repeat for all needed channels and leave unused channels alone. * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v271k.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red%Set up the IF inputs. I've assumed that the observing frequencies for X-band are between 8112 and 8624 MHz which is normal for the LBA. %red%If using XRCP, send these commands:
%red%@@dbbcifa=1,agc,1@@
%red%@@dbbcifb=4,agc,1@@
%red%@@pps_sync@@ %red%If using XLCP, send these commands:
%red%@@dbbcifa=2,agc,1@@
%red%@@dbbcifb=1,agc,1@@
%red%@@pps_sync@@ * %red%Confirm that the crossover switches are in the direct position. It's easiest to do this by starting up a system monitor. Connect to ops4 with @@shh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches” * Check the mk5b_mode line in the @@/usr2/proc/v271kke.prc@@ file. For 4 channels only, it should read as @@mk5b_mode=ext,0x000000FF,0@@ while for 8 it should be @@mk5b_mode=ext,0x0000FFFF,1@@. !!!X-band, dual polarisation * Create a new configuration file in @@C:\DBBC_CONF@@ of dbbcke if needed. If the experiment shares a configuration with a previous experiment (same frequencies, polarisations, channel order) then you should be able to use that. Otherwise, read on. Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Put all of the channels at one polarisation in lines 1-4 and have lines 5-8 for the other polarisation. If the schedule shows the channels as alternating between RCP and LCP, tell the LBA chat (Cormac and Chris by email) that the recorded channel ordering will be different. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-7600). As an example, if channel 1's lower band edge is 8200 MHz then the first line in the @@dbbc_config_file_v999a.txt@@ is then @@1 dbbc2.bit 600.00 16@@. Repeat for all needed channels and leave unused channels alone. * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v999a.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red% up the IF inputs. I've assumed that the observing frequencies for X-band are between 8112 and 8624 MHz which is normal for the LBA. %red%If using XRCP, XLCP, send these commands:
%red%@@dbbcifa=1,agc,1@@
%red%@@dbbcifb=1,agc,1@@
%red%@@pps_sync@@ %red%If using XLCP, XRCP send these commands:
%red%@@dbbcifa=2,agc,1@@
%red%@@dbbcifb=4,agc,1@@
%red%@@pps_sync@@ * %red%Confirm that the crossover switches are in the direct position. It's easiest to do this by starting up a system monitor. Connect to ops4 with @@shh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches” * Check the mk5b_mode line in the @@/usr2/proc/v999ake.prc@@ file. For 4 channels only, it should read as @@mk5b_mode=ext,0x000000FF,0@@ while for 8 it should be @@mk5b_mode=ext,0x0000FFFF,1@@. !!!S-band, single polarisation * Create a new configuration file in @@C:\DBBC_CONF@@ of dbbcke if needed. If the experiment shares a configuration with a previous experiment (same frequencies, polarisations, channel order) then you should be able to use that. Otherwise, read on. Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-1900). As an example, channel 1's lower band edge is 2209 MHz then the first line in the @@dbbc_config_file_v999a.txt@@ is then @@1 dbbc2.bit 309.00 16@@. Repeat for all needed channels and leave unused channels alone. * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v999a.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red%Set up the IF inputs. %red%For either single S-band polarisation, use
%red%@@dbbcifa=4,agc,2@@
%red%@@dbbcifb=2,agc,2@@
%red%@@pps_sync@@ * %red%Confirm that the crossover switches are in the correct position. For SLCP, the switches should be direct, while SRCP you need to have the switches crossed. If you do change this, please leave a note for the next observer!. To check the status, it's easiest to do this by starting up a system monitor. Connect to ops4 with @@shh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches” * Check the mk5b_mode line in the @@/usr2/proc/v999ake.prc@@ file. For 4 channels only, it should read as @@mk5b_mode=ext,0x000000FF,0@@ while for 8 it should be @@mk5b_mode=ext,0x0000FFFF,1@@. !!!S-band, dual polarisation - 4 channels maximum This is the configuration that is most fraught with hazard. It requires either physical recabling of the dbbc to put the correct S-band inputs into CoMos A and B, or requires the following (untested) procedure. If you use recabling, follow the X-band notes but use 1900 when working out dbbc frequencies. * Create a new configuration file in @@C:\DBBC_CONF@@ of dbbcke if needed. If the experiment shares a configuration with a previous experiment (same frequencies, polarisations, channel order) then you should be able to use that. Otherwise, read on. Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Put all of the channels at one frequency in lines 1-4 and have lines 9-12 for the other polarisation. If the schedule shows the channels as alternating between RCP and LCP, tell the LBA chat (Cormac and Chris by email) that the recorded channel ordering will be different. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-1900). As an example, if channel 1's lower band edge is 2209 MHz then the first line in the @@dbbc_config_file_v999a.txt@@ is then @@1 dbbc2.bit 309.00 16@@ as is the ninth line. If channel 2's lower band edge is 2225 MHz then the second and tenth lines will be @@1 dbbc2.bit 325.00 16@@. * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v999a.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red%Set up the IF inputs. %red%Send these commands:
%red%@@dbbcifa=4,agc,2@@
%red%@@dbbcifc=2,agc,2@@
%red%@@pps_sync@@ * %red%Confirm that the crossover switches are in the correct position. For SLCP/SRCP, the switches should be direct, while for SRCP/SLCP you need to have the switches crossed. If you do change this, please leave a note for the next observer!. To check the status, it's easiest to do this by starting up a system monitor. Connect to ops4 with @@shh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches” * Edit the mk5b_mode line in the @@/usr2/proc/v999ake.prc@@ file. For 4 channels only, it should read as @@mk5b_mode=ext,0x00F0000F,1@@.

!!!S-band, dual polarisation - 8 channels maximum This is the configuration that is most fraught with hazard. It requires either physical recabling of the dbbc to put the correct S-band inputs into CoMos A and B, or requires the following (untested) procedure. If you use recabling, follow the X-band notes but use 1900 when working out dbbc frequencies.

* Create a new configuration file in @@C:\DBBC_CONF@@ of dbbcke if needed. If the experiment shares a configuration with a previous experiment (same frequencies, polarisations, channel order) then you should be able to use that one in the next step. Otherwise, read on. Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Put all of the channels at one polarisation in lines 1-4 and have lines 9-12 for the other polarisation. If the schedule shows the channels as alternating between RCP and LCP, tell the LBA chat (Cormac and Chris by email) that the recorded channel ordering will be different. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-1900). Using v444b as an example, channel 1's lower band edge is 2244 MHz. The first line in the @@dbbc_config_file_v444b.txt@@ is then @@1 dbbc2.bit 344.00 16@@. The second RCP channel has a lower band edge of 2260 MHz and so the second line is @@1 dbbc2.bit 360.00 16@@. Lines 9-12 in the file are the same as lines 1-4 (as this sets these channels to matched frequencies) * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v444b.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red%Set up the IF inputs. %red%Send these commands:
%red%@@dbbcifa=4,agc,2@@
%red%@@dbbcifc=2,agc,2@@
%red%@@pps_sync@@ * %red%Confirm that the crossover switches are in the correct position. For SLCP/SRCP, the switches should be direct, while SRCP/SLCP you need to have the switches crossed. If you do change this, please leave a note for the next observer!. To check the status, it's easiest to do this by starting up a system monitor. Connect to ops4 with @@shh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches” * Edit the mk5b_mode line in the @@/usr2/proc/v999ake.prc@@ file to read @@mk5b_mode=ext,0x0FF000FF,1@@ !!!S/X-band, single polarisation * Create a new configuration file in @@C:\DBBC_CONF@@ of dbbcke if needed. If the experiment shares a configuration with a previous experiment (same frequencies, polarisations, channel order) then you should be able to use that. Otherwise, read on. Copy the basic layout from @@dbbc_config_file_lba.txt@@ to your new file and then edit the frequencies. Start by checking the listed frequencies of each channel on the ATNF Wiki. In the corresponding entry in your experiment's config file change the frequency to (lower band edge-7600). Using v469a as an example, channel 1's lower band edge is 8409 MHz. The first line in the @@dbbc_config_file_v469a.txt@@ is then @@1 dbbc2.bit 809.00 16@@. Repeat for all needed channels and leave unused channels alone. * %red%Load the configuration into the DBBC with the @@DBBC Client@@ command @@load=dbbc_config_file_v469a.txt@@ * %red%Reconfigure the DBBC with @@reconfig@@ * %red%Use the @@DBBC Client@@ to send the command @@dbbcform=geo@@ * %red%Set up the IF inputs. I've assumed that the observing frequencies for X-band are between 8112 and 8624 MHz which is normal for the LBA. ** %red%Send these commands:
%red%@@dbbcifa=1,agc,1@@
%red%@@dbbcifc=2,agc,2@@
%red%@@pps_sync@@ * %red%For RCP, confirm that the crossover switches are in the direct position. It's easiest to do this by starting up a system monitor. Connect to ops4 with @@ssh -X observer@ops4@@ and run @@monitor_system.pl@@. Select the relevant telescope & check the settings of the “Cross-over switches”. For LCP, the crossover switches should be crossed. * Check the mk5b_mode line in the @@/usr2/proc/v469ake.prc@@ file. For 8 channels it should be @@mk5b_mode=ext,0x0FF000FF,1@@.