GBT Status Display

Main

Usage

1. Introduction

The GBT Status Display is a console based display application. It displays various GBT specific parameters, sampled values and computed values. Special care was taken to promote its use for remote observing. It is simple to use; a user need only type "gbtstatus" and the default display will appear in the shell. It can be used as is or it can be tailored for a particular user's needs. A user may remove items or rearrange the items displayed on the screen. This is done by creating a Status section in the .sparrow file in the user's home directory and editing the Status section to suit their needs (See Examples). In the future we hope to allow the user to request the value of any M&C parameter or sampler that may be of interest.

1.1 The Basic design

There are two software programs that comprise the gbt status display system: a daemon and a display program. Both the daemon and the display program are written in python.

The daemon is the workhorse. It queries the M&C system via the Soap interface for the current values of relevant parameters and samplers. It queries FQL to obtain relevant information from FITS files e.g. scan type and scan sequence number. It formats and writes the results to the simple text file /home/gbt/etc/config/gbtstatus.txt.and to the gbtstatus MYSQL database at a 1Hz rate. One daemon sevices all the console display programs.. It runs on the host called "fire". The daemon is started as part of the normal M&C startup procedure. There is no direct interaction between the daemon and the user.

The display program is a lightweight program. This is the program that is started when the user types "gbtstatus". There can be many display sessions running at one time. On start up, the program reads the users .sparrow file and/or sparrow.conf file to determine what items should be displayed in the current gbtstatus console session. It queries the database for the values of these items and displays them at a 1Hz rate.

2. The Default Status Screen

The default status screen displays all of the currently supported items of the gbtstatus program.

2.1 The display items

Title	Origin	Field Name in Sparrow Configuration File
Duration	The scan length as reported by the ScanCoordinator	scan_length
Remaining	The time remaining in the scan as reported by the ScanCoordinator	remaining
Scan	A derived field: comprised of the scan number as reported by the ScanCoordinator, and PROCNAME, PROCSIZE and PROCSEQN from the FITS file	scan_number, scan_sequence, scan_total, scan_type
Scan Start Time	If scan has started it is the scan start time as reported by the ScanCoordinator - if the scan has not started, then it is the countdown for the start of scan	start_time and time_to_start
On Source	"Yes" or displays a countdown until the antenna is on source as reported by the Antenna	time_to_target
Source	The source name as reported by the ScanCoordinator	source
Source Vel	The source velocity as reported by the LO1	source_velocity
Observer	The observer name as recorded in the FITS file	observer
Last Update	The time when the database was last updated by the status daemon	last_update
Operator	Currently there is no place to acquire this information	operator
UTC Time	The UTC time of the last update	utc
UTC Date	The UTC date of the last update	utc_date
Project ID	The data directory of the FITS files as as reported by the ScanCoordinator (project ID)	data_dir
LST	The LST of the last update	lst
MJD	The Modified Julien Date	mjd
Status	The status reported by the ScanCoordinator	status
Time To Set	The time the current source sets	time_to_set
Receiver	The receiver as reported by the ScanCoordinator	receiver
Polarity	The receiver polarity as reported by the Receiver	rcvr_pol
Obs Freq	The observed frequency	freq
Rest Freq	The rest frequency as reported by the LO1	if_rest_freq
Cal State	'ON' if the noise diode was firing during the scan	cal_state
Sw Period	The switch period as reported by the ScanCoordinator	switch_period
Center Freq	The center frequency as reported by the LO1	first_if_freq
Vel Def	The velocity definition as reported by the LO1	velocity_definition
Vel Frame	The velocity frame as reported by the LO1	velocity_frame
Frequency State	The switching type: total power or frequency switching	switch_type
Coordinate Mode	The coordinate mode as reported by the Antenna	epoch
Major Coord	The telescope position in the major current Coordinate Mode as reported by the Antenna	major
Minor Coord	The telescope position in the minor current Coordinate Mode as reported by the Antenna	minor
Major Cmd Coord	The telescope position in the major current commanded Coordinate Mode as reported by the Antenna	major_commanded
Minor Cmd Coord	The telescope position in the minor current commanded Coordinate Mode as reported by the Antenna	minor_commanded
Antenna State	The telescope state as reported by the Antenna	ant_motion
Az commanded	The commanded az position of the telescope as reported by the Antenna	az_commanded
El commanded	The commanded el position of the telescope as reported by the Antenna	el_commanded
Az actual	The actual az position of the telscope as reported by the Antenna	az_actual
El actual	The actual el position of the telsecope as reported by the Antenna	el_actual
Az error	The difference between the commanded and the actual az position of the telscope as reported by the Antenna	az_error
El error	The difference between the commanded and the actual el position of the telsecope as reported by the Antenna	el_error
LPCs Az/XEl/El	The Local Pointing offset as reported by the Antenna	lpcs
DC Az/XEl/El	The Dynamic corrections as reported by the Antenna	dyn_point_cor
AS FEM Model	The state of the FEM correction model by the Antenna	as_fem_model
AS Zernike Model	The state of the Zernike model correction model as reported by the Antenna	as_zernike_model
AS Offsets	The state of the Active surface zero offsets as reported by the Antenna	as_offsets
LFCs (XYZ mm)	The Local Focus offset as reported by the Antenna	focus_offset
LFCs (XYZ deg)	The Local Focus Tilt offset as reported by the Antenna	focus_tilt_offset
DC Focus Y (mm)	The Dynamic correction Y subreflector offset as reported by the Antenna	dyn_focus_cor
Temp	The current temperature as reported by Weather2	ambient_temperature
Wind Vel	The current wind velocity as reported by Weather2	wind_velocity

2.1.1 The IF Path Information

The IF paths in use are always displayed in the last section of the gbt status screen. An example screen is shown below.

Each line represents the IF path for 1 polarization path from the IFRack to the backend. Each line contains only the devices in use for the listed path. A path may include a subset of the devices and values listed in the table below. For IF paths containing the Spectrometer, the path will be displayed in "RED" when the duty cycle varies 2.5 db from the optimal value. The nomenclature used is:

Label	Value
IF #	The # displayed is the number corresponding to the IFRack switch in use. The value displayed is the RF power coming out of the IFRack
CM #	The # displayed is the number corresponding to the Converter Module in use. The value displayed is the RF power coming out of the Converter Module after the mixer and before the Converter Module filters
CF #	The # displayed is the number corresponding to the Analog Filter in use. The value displayed is the RF power coming out of the Analog Filter Rack after all filters have been applied (used with 100MHz Converters
SG #	The # displayed is the number corresponding to the Analog Filter in use. The value displayed is the RF power coming out of the Analog Filter Rack after all filters have been applied (used with 1.6Ghz Samplers
ACS-Port #	The # displayed is the number corresponding to the port of the Spectrometer in use. The value displayed is the duty cycle in db
SPP-Port #	The # displayed is the number corresponding to the port of the SpectrarlProcessor? in use. The value displayed is the power level in db
GASP-Port #	The # displayed is the number corresponding to the port of the GASP in use
BCPM-Port #	The # displayed is the number corresponding to the port of the BCPM in use
CGSR-Port #	The # displayed is the number corresponding to the port of the CGSR in use
Radar-Port #	The # displayed is the number corresponding to the port of the Radar in use
DCR-Port #	The # displayed is the bank and number corresponding to the port of the DCR in use. The value displayed is the total power
backendIF	The value displayed is the frequency of the doppler track rest frequency as seen by the backend
TSYS #	The # displayed is the number corresponding DCR port in use. The value displayed is the system temperature as reported by the DCR

2.2 Resizing and Navigating in the Display

An auto-page scroller is also provided. To use thils -lrt ~s feature type 'a'. The auto-scroller will beging to scroll the page at a 2 second interval. Typing 'a' again sets the auto-scroller to 5 seconds, another 'a' sets the auto-scroller to 10 seconds. To return to the non -auto-scrolling mode, type 'a' from the 10 second auto-scroller mode. The user may hit the spacebar at any time to view the next page.

The display can be resized by grabbing any edge with the mouse and stretching/shrinking it to the desired size. The gbtstatus screen will recalculate the number of pages required and reformat the current page appropriately.

The display was set up to maixmize screen space. A two column approach wa used. It is possible that the display may not be wide enough to display all field values. In the snapshot below the Scan field can not be fully displayed with the current width of the window. When this occurs, a red line will appear on the vertical right edge of the screen. The user may resize the window or continue with the current screen size.

2.2.1 How do I make the font size bigger?

before

xterm -fn 10x20

3. Customizing the Display

The gbtstatus program uses the .sparrow file in the users home directory to locate the items that should be displayed. If the file does not exist or the .sparrow file does not contain a [Status] section, the gbtstatus screen uses the default sparrow.conf file located in the /home/sparrow/release directory. The user can edit the Status section of his .sparrow file in order to remove items that he is not interested in. The order in which items are displayed can easily be modified and separating lines can be added. These examples show how different .sparrow files are displayed by the status screen.

4. Known Issues

It is required that the display be set to a reasonable size. If the display is set to a very small size the program exits. A fix is in place and can be patched in at any time.

After initially receiving data from the M&C interface, there is not an obvious indication to the user that this interface is not working properly.

The daemon may not consistently update at a 1Hz rate. Early tests (before some optimizations were performed) show that the approximate loss is, on average, one one-second sample every 265 samples (4.45 minutes). The losses usually occur in clusters, due to slow response times from the M&C interface, FQL or file I/O. The FQL and text file issue appears to be an NFS issue. The M&C interface issue is most likely caused by managers being "busy" and not promptly responding to requests by Grail.

5. Core Team

Scientific Sponsor:	KarenONeil
Technical Leads:	MelindaMello
Project Scientist:	KarenONeil

-- MelindaMello - 15 Nov 2004

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