ATCA Users Guide: 3.3 Monitoring and Trouble Shooting

3.3 Monitoring and Trouble Shooting

3.3.1 Stop Start Problem

When CAOBS is first started, it is possible for the correlator and CAOBS to be out of sync. In this case, there will be no update of data in SPD or VIS and the correlator XXX window will have a new message every cycle reporting:

correlator error message

The solution is to issue a stop, then restart observing.

3.3.2 No Correlation

There are a number of problems that may result in loss of correlation.

3.3.2.1 Conversion System Out of Lock

It is possible to loose lock in the conversion system. Check the following in MONICA. Currently there isn’t a standard page with these in it and you have to create your own pages in MONICA (see below)

CL1F1 PLL Lock is locked
CL1F1 Expected Reference Frequency (the freq the module is expecte to tune to)

To create a new page in MONICA that monitors the CABB conversion system

In MONICA choose

Window

==> New Window

==>Setup

==> Add panel

==> Time Series

This brings up the page for setting up a time series

Choose 12 hours
Choose CABB in the Select Items window

Optical Power Photodiode biases need to be a reasonable value (if < 0.1mA will lead to loss of lock *nomially 0.2 mA)

Won’t get any sync errors, correlator will look ok, but no correlation because tuned to the wrong frequency

/1./	The Australia Telescope Compact Array
/1.1/	The Australia Telescope National Facility
/1.2/	Overview of the ATCA
/1.3/	Planning a proposal
/1.4/	Centimetre Observations (20–3 cm bands)
/1.5/	Millimetre-wave observations (12mm–3mm)
/1.6/	Choosing an Observing Frequency
/1.7/	Choosing Angular and Frequency Resolution
/1.8/	Additional Observing Notes and Techniques
/1.9/	High Time Resolution, Pulsars, Planets and VLBI
/1.10/	Other Things to Consider
/1.11/	Submitting a proposal
/1.12/	Successful Proposals

/2./	Preparing for Observations
/2.1/	How to Prepare a Schedule File
/2.2/	How to Prepare a Mosaic File
/2.3/	Scheduling Strategy
/2.4/	Observation Requirements
/2.5/	Pre-observation Checklist

/3./	Observing
/3.1/	Continuum Observations
/3.2/	Zoom Modes
/3.3/	Monitoring and Trouble Shooting
/3.4/	cm Observing Startup Checklist
/3.5/	mm Observing Startup Checklist

/4./	After your Observations
/4.1/	Archiving Your Data
/4.2/	Report Your Experiences
/4.3/	Data Analysis
/4.4/	Publishing Results