Starting from Data Viewer V4.0, $DVPATH has to be set to the path where Data Viewer is installed.
To start the Data Viewer, type
e.g. $DVPATH/dataviewer -s 131.215.113.11
This will start the Data Viewer Control:
Clicking the Play button at the upper left part the control panel will start the Xmgr display window. By default, 16 channels will be displayed in real-time mode. Note: some graphs may look blank, which means Y-Axis settings need to be adjusted (see the topic Adjusting & Saving Settings below).
Other options: (type dataviewer -h to see all options)
Data Viewer can also be started by
if frame files are going to be used as data sources instead of a server. See Frame File for the usage.
Changing Signals
To change the signal for a particular channel, first open the
Signal Selection window by clicking
Main on the top
panel and select Signal Select from the pull-down menu.
The area under Group Names shows all of the current
available groups. Clicking on any group name, the Signal Names
will show the list of signal names inside the group.
When Fast Chan. (or Slow Chan.) is selected, only fast
(or slow) channels are shown. Select the desired signal. Then
select the channel number by entering the number at the New signal
selected for Ch. field or using the increasing/decreasing arrow buttons.
Click Select to make the change.
All channels can also be changed at once by using Main->Restore
if there is a pre-saved file.
Adjusting & Saving Settings
To adjust X or Y Axis settings for a channel: First select the channel from the channel select panel which is located at the right side of the control pannel.
X Axis: X-Axis is in seconds. The selection can be made from the pull-down menu X Axis. The maximum is 16 seconds and the default is set to 8. A Delay can be set in 1/16 second of increment.
Y Axis: To adjust Y scales, hand type the range in the Y Scale Min and Max text fields. Different types of Y Scale are also available. See Y Scale Type for details.
Auto:By selecting AUTO, Xmgr will automatically set the proper display Y-range for the selected channel. However it is not recommended to use auto setting for the general display since it may slow down the display. AUTO should be used only for locating the curve and then Y-Axis scale should be set manually.
Global Setting: If Globle Settings (located at the lower
left corner of the control panel) is checked, the adjustment will
affect all channels.
Once all settings are adjusted, you may save them to a file for later
recalls. To save, use Main->Save; to restore, use
Main->Restore from the top
panel.
Display Action
Stop: While in
(Stop), the Xmgr
display is in an interactive mode. You may use any Xmgr menu or buttons.
For the usage of Xmgr, see
Xmgr User
Guide.
Play:
If 
(Play)
is selected, data is displayed in a real-time mode, with possibly a
1-2 second delay from the time it is actually acquired. The display
is in general updated once per second; and for certain cases it could
be updated up to 16 per second (see later topic
Refresh Rate for more details).
Pause:
The 
(Pause)
feature is designed for trend
data display only. Pressing this button will stop the display while
the real-time trend data being recorded. To resume, select Play
again. For non-trend display it works as same as Stop.
Playback
Along with real-time data display, data stored by the Data Server may also be recalled for presentation in Xmgr. Playback produces one or more new Xmgr window(s) and displays all information for the given display period at once. Note: It will not start the display until all of the data information has been read. Thus longer display period and more channels require longer loading time.
To use Playback, select the Playback from the Main menu. This will bring up the Playback control panel. Up to 16 channels can be chosen from the left panel of the Playback control.
- Time Settings for Playback:
- reference time: the first line of the time seting is
the time for starting or ending the display, depending on the choice
of the toggled menu Stop Time/Start Time.
To set it, enter
the year, month, day, hour, minute, and second into the fields at the
first row of Time Settings. To quickly set all fields to the current
time, simply click Quick Set.
duration: the second line of the time setting is the length of time period for playback. Enter the days, hours, minutes, and seconds into the fields at the second row.
There is also a choice of using GPS time instead of UTC time for the setting.
- example:
reference time: 00:09:08:18:58:38
- duration: 0:5:10:15
- in Start Time: The Xmgr will display data starting from the reference time. It will last for the length of the display period, with refreshing for each second increment. e.g. in the above setting, it will display from 18:58:38 until 00:08:52 the next day.
- in Stop Time: The Xmgr will display data of the display period and end by the reference time. Therefore in the above example, it will start from 13:48:23 and play until 18:58:37, refreshing for each second increment.
- example:
- reference time: the first line of the time seting is
the time for starting or ending the display, depending on the choice
of the toggled menu Stop Time/Start Time.
To set it, enter
the year, month, day, hour, minute, and second into the fields at the
first row of Time Settings. To quickly set all fields to the current
time, simply click Quick Set.
- Playback Options:
- Decimation: Data decimation can be chosen as full data, second trend, minute trend, 10-minute trend, or hour trend. The default is set as the following:
Decimation Display Period full data less than or equal to 10 seconds second trend between 10 seconds and 1 hour minute trend between 1 and 60 hours 10-minute trend 60 hours to 30 days hour trend more than 30 days
- X-Axis Format: There are two types of X-Axis formats can be chosen for trend data display: The Date/Time choice will show X-Axis in yy-mm-dd hh:mm:ss format. And the Total Time shows the X-Axis in seconds (if the period is shorter than 60 minutes) or minutes.
- Graph Mode: Standard displays selected channels in one Xmgr window, with each channel in a separated graph. Multiple display all selected channels in the same graph. Multiple Xmgr opens a new Xmgr window for each selected channel.
- More Options: You may choose to show the maximum, minimum, or/and mean values. It will display Mean if none of them is chosen or if more than one is chosen for the multiple case. You may choose to show or hide the X and Y Grid. You may also connect to a different server rather than the server which is used at the starting of the main control panel by typing the server IP and port number into the corresponding fields.
- Decimation: Data decimation can be chosen as full data, second trend, minute trend, 10-minute trend, or hour trend. The default is set as the following:
- Play Frame Files:
Playback can also display data from frame files. See Other Main Menu Items: Frame Files for how to open frame files. Quick Set button will set the maximum time range for the available data in the frame files.
Display Type
Two display types can be chosen from the pull-down menu Display Type. The selected display type is indicated on the display type field as shown in the figure. Full Data: It displays full data in time domain.
The X-Axis shows time in seconds and Y-Axis is in ADC counts. Up to 16
seconds
of data are plotted in each graph. The larger graph at the left upper
corner will show the plots for the selected channel which can be changed
from the channel select panel.
Trend Data: Trend data (maximum, minimum,
and mean values) can be viewed in real-time.
- Settings: The X-Axis shows the length of the time period (in seconds) of trend being displayed. It resets itself to zero every 12 hours (43200 seconds). While resetting, all Xmgr sets will be saved automatically to a .save file with the time stamp as its name.
1. The larger graph at the left upper corner can be turned on/off.
2. The real-time trend display can be paused by clicking Pause button. Use Play to resume. Some data may get lost if being paused for long time.
3.Off-line data playback should be viewed by Playback.
Display Mode
Standard displays up to
17 graphs. The larger graph at the upper left corner shows the plot
for the selected channel. Other graphs can show up to 16 channels,
with channel number 1 at the lower left and increasing to the upper right.
Note: the larger graph at the upper left corner
can be turned on/off by checking/unchecking the Show Sel. box.
Multiple displays up to
16 channels in the same graph.
Other Display Options
No. of Channels: It is the total number of the channels to be displayed. The default is set to 16.
Resolution: The resolution of
full data display is adjustable.
Each channel will be displayed at the chosen resolution or the data sampling
rate of the signal, whatever is smaller. The default is 128 Hertz and the
maximum is 16384.
- Note: In order to keep up the display speed, an limit is set
for the number of points appeared in a graph. Thus choosing higher
resolution may result in
reducing the total display time (X-Axis range). Here is the chart:
Resolution Maximum Time 128 16 sec 256 8 sec 512 4 sec 1024 2 sec 2048 above 1 sec
Refresh Rate: In general, the refresh rate for graphing is once per second. It is adjustable up to 16 times per second by using the pull down menu Refresh Rate.
Filter: Moving Average Filter can be applied to the signals by selecting the Filter check box. Average is computed over 9 point intervals.
Y Scale Type: Four types of Y-Axis scale for each channel are available: Linear, Exp, Log, or Ln. The default is Linear. To change Y scale type for a particular channel, first select the channel number from the channel select panel, then use the pull down menu Scale which is located at the right side of the control panel to select the scale type.
Selected Signal On/Off:
There is a check box next to Show Sel. (shown in the picture).
This gives an option to turn on/off the large graph at the upper left corner
which shows the selected channel in standard display.
Color Selection: There are 6 choices
under the color selection:
green, white, red, blue, yellow, and multiple.
Trigger
Trigger Control is located at the lower right
part of the main control panel:
Other Main Menu Items
Frame File
One of the features added since Version 4 is to view data from Frame
files or Toc files. Under the menu Main->Frame Files there
are three options:
Make TOC File: Point to the directory which contains
ONLY Frame files to generate a Toc file. The generated Toc file
will be placed in the same directory under the name "outtoc".
Note: Toc file could be generated without using
Data Viewer. Run
It is assumed the Frame file directory contains only the Frame files.
Open TOC File: Point to the Toc file which will be displayed, then click Apply.
Sometimes it is impossible to generate the TOC file because the file size could be too big. In this case you may open Frame files directly.
Open Frame Files Directory: Point to the directory which contains ONLY Frame files and click Apply. ( Note: as the current version, the display time period will not be selectable while playing trend data from a Frame file directory.)
After open a Toc file or a Frame files directory, use Playback to display the data.
Printing
Print to printer: You may use the Print feature from Xmgr.
First stop the display. Then click on File located at
upper left corner of the Xmgr window. Choose Print from the pull-down
menu and the picture will be sent to the default printer.
Print to ps file: Select Main->Print to File. The current display will be saved as a .ps file with the time stamp as the file name, i.e., 99-9-15-18-24-19.ps . Note that you do not have to stop the display to use this feature.
New Connection
This will set the existing (if any)
Xmgr window free from the Data Viewer Control. The Xmgr may be closed
in the same manner of closing a X-term. The basic settings are
saved and will be restored automatically and another new Xmgr window
will be opened.
New Configuration
This feature is used when there is anything changed in the
configuration file or when data server is re-started.
Exit
Choosing Main->Exit will exit the Data Viewer program. If you
need to save the current settings, use Main->Save before
exiting.
Other Tips
Note: Make sure the Xmgr is in an interactive mode (Stopped) before applying any of the followings.
- data status: Xmgr allows user to view data information for each graph. Click on the graph you want to look at. Then select Data->Status from the pull-down menu of the Xmgr window. A status window will pop up and the information such as X and Y maximum/minimum is displayed. This is a convenient way to find out the the proper display range. Thus Y-axis range can be set accordingly.
- save Xmgr file: the current plots can be saved as a Xmgr file and reopen by Xmgr. Use the pull-down menu File->Save as and type in a file name. To reopen, use File->Open.
- adjust scales: X and Y scales are adjustable from Xmgr directly. Use Plot->World scaling.
Status Report/Debugging Information: Status report and debugging information are shown at the special status report window if using $DVPATH/dataviewer, or at the terminal window where the Data Viewer Control is started if using $DVPATH/dataviewer0. It shows the general display information, user's selections, warnings and error messages. While data being displayed, it shows the time stamp of the data and indicates any block drop as well. It is advised to check the message window whenever you experience something 'weird'.
Note: Always check the status messages first. It may help you to target the problem sooner.
- problem: can not start the Data Viewer Control.
possible causes:
1. the variable $DVPATH is not set.
2. no data server is available.
suggestions:
1. set the variable $DVPATH to the directory where Data Viewer is installed.
2. make sure the server IP address is typed correctly and the server is running.
- problem: Data Viewer hangs.
possible cause: too many message queues are running on the current machine.
suggestion: check the list of message queue (ipcs -b) and kill the ones which are not in use (ipcrm -q < Queue ID >)
- problem: real-time Xmgr display doesn't keep up the speed.
suggestions:
1. set smaller X-Axis range.
2. do not use AUTO setting for display.
3. display less channels, especially when higher refresh rate is used.
4. reduce the resolution.
5. reduce the refresh rate.
- problem: unexpected Xmgr display interuption.
possible causes:
1. the display is triggered.
2. the selected channel number is larger than the total channel number.
suggestions:
1. see if the Trigger Enable box is checked and check the status report.
2. select larger number for the total number of channels; or move the signal to a channel with smaller channel number.
- problem: no action being taken after a selection.
possible cause: the connection between control and display is not established; this could be caused by a network error.
suggestion: check the status messages on the message window. The linemessg received *************************
should appear after each selection. If not, select Main->New Connection to quit the current Xmgr display and start a new one.
- problem: graphs flash in Xmgr display.
possible cause: AUTO settings are being used for two or more channels.
suggestion: unckeck Auto and manually set Y Axis ranges for all channels. see the Usage of AUTO Setting under the topic Adjusting/Saving Settings.
- problem: Playback doesn't show all the data requested.
possible cause: there is no enough data stored by the Data Server.
Back to Main Page
The latest version is set at http://www.ligo.caltech.edu/~hding/Dataviewer/help.html
Contact: Hongyu Jane Ding <hding@ligo.caltech.edu>
Last modified: Tue September 18 2001