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--- operations:documentation:lba_dbbc_config [2013/03/28 04:12]
Jim Lovell
+++ operations:documentation:lba_dbbc_config [2013/03/28 05:18]
Jim Lovell [S-band, dual polarisation - 4 channels maximum]
@@ Line 25: / Line 25: @@
 </code>
+As the notes on [[hardware:dbbc.routing|how signals are routed through a DBBC]] describe, we only need one CoMo as there's a common input IF and all frequencies are in the band of Filter 1 (512 - 1024 MHz). So we can drop ''ifb'' and ''lo=lob...''. The input IF is X-band RCP which in input 1 and we want automatic gain control. The input power level for Ke in CoMo A [[operations:currentissues|should be 38000]]. So ''ifd01'' should be edited to look like this:
+<code>
+define  ifd01         13073035822x
+ifa=1,agc,1,38000
+lo=
+lo=loa,7600.00,usb,rcp,off
+enddef
+</code>
+Drudg produced a ''dbbc01d'' procedure that looked like this:
 <code>
@@ Line 36: / Line 46: @@
 </code>
+The LO frequencies are correct but we want to use BBCs 01 to 04 and CoMo A. So the revised version looks like this:
+<code>
+define  dbbc01d       13073035822x
+bbc01=809.00,a,16.00
+bbc02=825.00,a,16.00
+bbc03=841.00,a,16.00
+bbc04=857.00,a,16.00
+enddef
+</code>
+Lastly, in ''setup01'' the mark5 mode needs checking. We start with
+<code>
+mk5b_mode=ext,0x0000CCCC,0
+</code>
-''dbbc01d'' and ''ifd01'' procedures to get the input bands, BBC channels etc configured correctly.
+However, we want to pass through all bits from the first 4 BBCs, so it needs to be changed to this:
+<code>
+mk5b_mode=ext,0x000000ff,1
+</code>
+===== X-band, dual polarisation =====
+As an example, here's how V465b has it's frequencies set up according to the LBA wiki:
+{{:operations:documentation:screenshot_28_03_13_3_32_pm.png|V465b frequency setup}}
+Running ''drudg'' on the VEX file produces the following IF setup for Ke (note you may get some warning messages, just persist and produce the files anyway):
+<code>
+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
+</code>
+As the notes on [[hardware:dbbc.routing|how signals are routed through a DBBC]] describe, we need two CoMos, one for X RCP and one for X LCP. The first four BBCs will need to be one polarisation (RCP) and the second four (from CoMo B) LCP. A note to the correlator and whoever is running fringe checks should be sent.
+The input IF for CoMo A is X-band RCP which in input 1, and for CoMo B X LCP is on input 1, and we want automatic gain control. The input power level for Ke in CoMos A and B [[operations:currentissues|should be 38000 and 33000]] respectively. Lastly, we might as well make the ''lo'' settings correct (although they don't actually do anything to the DBBC). So ''ifd01'' should be edited to look like this:
+<code>
+define  ifd01         13075124605x
+ifa=1,agc,1,38000
+ifb=1,agc,1,33000
+lo=
+lo=loa,7600.00,usb,rcp,off
+lo=lob,7600.00,usb,lcp,off
+enddef
+</code>
+Drudg produced a ''dbbc01d'' procedure that looked like this:
+<code>
+define  dbbc01d       00000000000x
+bbc02=793.00,a,16.00
+bbc04=809.00,a,16.00
+bbc06=825.00,b,16.00
+bbc08=841.00,b,16.00
+bbc01=793.00,a,16.00
+bbc03=809.00,a,16.00
+bbc05=825.00,b,16.00
+bbc07=841.00,b,16.00
+enddef
+</code>
+The LO frequencies are correct but we want to use BBCs 01 to 04 and CoMo A for the RCP frequencies and BBCs 05 to 07 and CoMo B for LCP. So the revised version looks like this:
+<code>
+define  dbbc01d       13075124605x
+bbc01=793.00,a,16.00
+bbc02=809.00,a,16.00
+bbc03=825.00,a,16.00
+bbc04=841.00,a,16.00
+bbc05=793.00,b,16.00
+bbc06=809.00,b,16.00
+bbc07=825.00,b,16.00
+bbc08=841.00,b,16.00
+enddef
+</code>
+Lastly, in ''setup01'' the mark5 mode needs checking. We start with
+<code>
+mk5b_mode=ext,0x0000FFFF,1
+</code>
+This is correct in this case as we haven't changed which BBCs we're passing through, just their frequency and polarisation assignments.
+===== S-band, single polarisation =====
+The setup here is essentially the same as for X-band single polarisation except the [[hardware:dbbc.routing|IF inputs]] and LO frequencies will differ.
+===== 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 note the [[hardware:dbbc.routing|IF inputs]] and LO frequencies will differ.
+If not re-cabling, then read on...
+In this case the [[hardware:dbbc.routing|IF inputs]] setup dictates that you will have S-band LCP through CoMo A input 4, and S-band RCP through CoMo C, input 2.
-** 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 [[http://www.atnf.csiro.au/vlbi/wiki/index.php?n=LBAApr2012.V271K|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.
@@ Line 137: / Line 198: @@
 * %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@@.

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