Robert C. Byrd Green Bank Telescope

NRAO Green Bank

Toney Minter

21st March 2002
GBT Software Project Note 19.3

GO Switching Signals Implementation

PDF Version

Abstract:

This document describes how GO has implemented switching signal schemes. The switching signals can be set either by a single button - the GO switching signal keyword - or by setting each individual YGOR parameter. This document will be primarily concerned with the interaction of these two methods of setting the switching signals.

N.B. GO does not currently implement polarization switching. Polarization switching is included in this document to provide a rough outline of how it might be implemented in the future.

History

4th February 2002

Initial version.

7th March 2002

Add warning in abstract that GO does not currently have an implementation of polarization switching. Add the history section. Added switchDeltas and xferState to list of YGOR switching signal parameters. Changed the list of possible switch_mode values: added information on beam and polarization switching; added GO FITS keyword values; removed ``Switching'',``Switching, No Cal.'', ``Symmetric Switching'', ``Sym. Switching, No Cal'' and ``Symmetric Total Power''; added ``Freq Switch, 01'', ``Freq Switch, 12'',``Freq Switch, 0102'', ``Freq Switch, User Def.'', ``Beam Switch'', ``Beam Switch, User Def.'', ``Pol. Switch'', ``Pol. Switch, User Def.'', ``Freq Switch, 01, No Cal'', ``Freq Switch, 12, No Cal'',``Freq Switch, 0102, No Cal'', ``Beam Switch, No Cal'' and ``Pol. Switch, No Cal''. Added information on GO's setting values of additional YGOR switching signal parameters. GO not longer determines the switch_mode at startup but assumes that it is ``User Defined''. Add information of what happens to GO's switching scheme if YGOR managers are reset. Remove section on ``Beam, Frequency and Polarization Switching.''

14th March 2002

Add section on position switching and when LASTON and LASTOFF are reset. Also add section on what keywords are changed when switch_mode is changed.

21st March 2002

Added the forgotten ``Total Power With Cal, Spectral Processor'' mode. Fixed errors with the cal_ctrl switch being omitted from the mode definitions.