Observations: EHT with R2DBE

Prerequists

• Go through the setup instructions and verify that the system is up and running.

R2DBE-Procedure

• on each of the recorders restart the dplane/cplane daemons:

m6service_restart

wait for the cplane and dplane log windows to appear. If the windows don't appear log-out of the recorder and log back in with the -X option.

• Prepare the Mark6 machines (recorder1 to recorder4) for recording. Instructions.

Note: instead of defining and commiting the input_streams in da-client you can use (on the recoder as user oper):

m6_addstreams_eht

• Download the vex-schedules (typically found on the EHT wiki) and copy them to /home/oper/shared/schedules on the control computer.

1. Download from the EHT-wiki to mrt-vlbi or mrt-vlbi2
2. on mrt-vlbi or mrt-vlbi2: scp {vex-files} oper@vlbicc:/home/oper/shared/schedules

• Translate the vex schedule

on any of the recorders (as user oper):

cd /home/oper/shared/schedules
vex2xml.py -f {vex-file} -s {code}

NOTE: the two letter code given as {code} must match exactly (case-sensitive!) the code assigned to Pico by the vex file. Normally it is Pv. If in doubt  open the vex-file and check the $STATION section.

This will create an output file named like the vex file but with an .xml extension (hereafter {schedule.xml})

Open the created {schedule.xml} file and verify that it is not empty. If it is empty check again the two letter station code you have given in the last step.

• Start the schedules:

on all 4 recorders:

cd /home/oper/shared/schedules
M6_CC -f {schedule.xml}

Note: starting the schedules can be done at any point prior to the session.

•  Start the automatic gain control:

on the control computer (as user oper):

start_eht.py  /home/oper/shared/schedules/{schedule.xml}

Field System

The field system is used for driving the telescope and to log information relevant to the observations

• Download the schedules and copy it to /usr2/sched on mrt-vlbi (the standard VLBI PC).
• Log into mrt-vlbi as user oper
• create field system files from the vex schedule

cd /usr2/sched
drudg {vexfile}
    select station code (typically Pv)
    select option 3 (=make snap) <enter>
    select option 0 (quit)

This will create a  file:

/usr2/sched/schedulename.snp

where schedulename is the name of the vex-schedule + pv (e.g. e17j28pv)

• start the field system. On mrt-vlbi go to the "Field System" desktop. Click on the "Field System" icon.
• Ignore any errors concerning dbbc or mk5
• In the oprin terminal issue:

schedule=schedulename

Troubleshooting

Restarting daemons: need new input_streams, m6service