Pulsar Instruments

Make sure that the S220 switch in the right-hand room (main rack, second from the left, bottom) is switched from VLBA mode to Normal mode.

Check DFB is cabled into the correct beam and correct reciever.

1. Use astrobone or another X11 enabled PC. Log into DFB system
2. ssh -X corr@134.104.64.137 (psw: h1pass.no)
3. At the prompt, type:

dfbcontrol

A few windows will appear. In the DFBcontrol window hit return to start tkDs (command gui) and read in setup for the receiver.

In the DFBcontrol window type:

@setup7beam.dfb

Note: You can make any file you want and read it with "@filename"

Wait until the config window programs. If there is an error instead of loading properly in the DFB control winow stop and restart (dfbcontrol) again:

 > kill
 > quit

Sometimes you have to kill and restart more than one times until it programs properly

On dfb control window select the source. In most cases it needs full declination DDDD:

> psr RRRR+/-DD 

Open a new file. It is good to use the following style:

> fo EFF_SOURCE_SCANnumber.fits

start observing:

> go

Until you want to stop. Wait until the state goes to stopped, it takes around 20 seconds:

> stop 

Close the file:

> fc

Notes: In the part of the observation (go) you might get some problems and error messages:

• The one in red saying SYNCCC:Correlator CONFIG BAND 1BW=256.00 is normal so don't worry about it.
• If there are messages in blue letters like "XFER error from l-bcc11" then you have to stop, close the file and try again by opening a new file. If you get it again kill and restart.
• If there is a message "PSREPHEM-entry DM2(or P4 or…) not in table" "CORDAT:Error writing SUBINT to FITS file" then it cannot read properly this pulsar, so for now just change source.
• If there is a message "SYNCCC:CLIENT DISCONNECTED" (the status will also be waiting for connection) then kill and restart.

On the DFB window prefix while observing the spd commands can be used to check different displays

• select displayed channels 70-230:

> spd chan 70,230

• display bandpass

> spd sel aa,bb
> spd sel bi

* display profile
> spd sel dp

* starts averaging
> spd avg

• stops averaging

> spd noavg

Remember: When you change pulsar and in the previous you where using spd avg, it will continue adding the pulses in the previous display. So execute the following:

>spd noavg
>spd avg

First configure the DFB with a search config file: e.g. In the DFBcontrol window enter

> @search7beam.dfb

Note: the configuration file should, in principle, set all the necessary parameters, like Obs Type (pull-down menu) —> "WBPSR"

> ssamt <sampling time in seconds> (Min. suggested sample rate 50 us)
> snbits <number of bits per sample>
> snprod <recording mode> 

The modes are "1" for just the total flux, "2" for the two pol channels and "4" for all four Stokes. All of the above parameters can still be changed after configuring by entering the respective command in either the tkDs window (at the bottom) or in the DFBcontrol window. Example: For 4.8 GHz observations, you can change the observing frequency by entering

> freq 4850 (Warning: the frequency is always entered in MHz)

Before you start recording search data, the DFB must set the levels for the region in the sky you are pointing the telescope. Note that no file is needed for this operation. And, again any command can be entered in either the tkDs or the DFBcontrol

> sset

> go

wait for ~ 30sec and then

> stop

Now, you can start searching properly. In the tkDs

> search

> fo <filename>
> go 
> stop 
> fc

The data can be found in: corr@134.104.64.137:/DATA1/PDFB4_1/