TChart Configuration

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Chart Options
EPICS Environment
Configuration File Options
Global Configuration File Options

TChart maintains a configuration file in the user's home directory. In addition a "global" configuration directory can be specified via command line switch -c.

TChart reads the specified configuration file on startup and updates some sections of the file whenever configuration parameters are changed via the File >> Preferences dialog.
It is therefore not advisable to manually edit the configuration file.

The File >> Preferences dialog shows the following sections and items:

Chart Options

Note:
These options can be changed with the configuration dialog (
File >> Preferences).
Changing the options listed in this section by editing the configuration file is not recommended. They will be overwritten by changes to the File >> Preferences dialog.

Look and Feel

Background
The chart background can be switched between black and white.

Data connect line / step
If "line" is selected, consecutive data points are connected by a straight line.
If "step" is selected, a horizontal line is drawn from the previous data point to the x-coordinate of the next data point. Then a vertical line is drawn from to the y-coordinate of the next data point. This shows the correct data value vs. time.

Motion jump / scroll

Legend
The legend can be positioned in the top/left, top/right, bottom/left, or bottom/right location of the plot.
Visiblility of the legend can be toggled using the "L" shortcut key.

Strip chart width (sec)
The initial, unzoomed width of the strip-chart viewport.

Display update (sec)
This parameter determinies how often the Strip-chart display is refreshed. Fractions of a second may be entered.

Zoom/Pan Options

X-zoom / Y-zoom
These parameters determine the viewport fraction by which a zoom command reduces or enlarges the viewport. A small value makes zooming less "jumpy", but more zoom commands are needed to achieve a given zoom factor.

X-pan / Y-pan
These parameters determine the viewport fraction by which a pan command moves the viewport. A small value makes panning less "jumpy", but more pan commands are needed to move the viewport  by a given time interval.

X-empty
This parameter determines the size of the empty screen fraction after an X-jump occurs.

Strip update (msec)
This update time determines how often the chart is refreshed (and how often data are written to file) if there are no monitors received for the traces. If the stip-charted PVs are "quiet", i.e. don't change very often, a larger value of this parameter can be used to allow a longer time interval to be displayed before the trace buffer is trimmed and/or to reduce the size of the data file.

Pan/Zoom
By changing this radio-button selection, the x-pan and zoom behaviour can be selected.

Y-Zoom mode
By changing this radio-button selection, the Y-zoom and pan mode can be selected.
If the common axis is shown (white on black background or balck on white background)  all graphs respond to zoom/pan operations.

Miscellaneous

PV Case
A convenience parameter for PV input. This parameter allows the selection of the case for PV names. If "upper" or "lower" are selected, TChart converts PV names entered in text fields to the selected case irrespective of the user input.

Y-Auto Range
This radio group controls the auto-range calculations. The auto ranges can be set to +/- 120%, the nearest power of 2, or the nearest power of 10 of the min/max values of the traces.

Start with unconnected PVs
If this check-box is checked, any PVs which are not connecting when a strip-chart is started will be ignored and the strip will be started.
If this check-box is not checked then PVs which are not connecting prevent a strip from starting. The user is prompted to correct the PV list.

New traces empty
If this check-box is checked the PV text fields in the traces dialog will start empty.
If this check-box is not checked the PV text fields in the traces dialog will be preset with the values from the previous strip.


EPICS Environment

EPICS parameters are retrieved from the environment variables  EPICS_CA_SERVER_PORT, EPICS_CA_REPEATER_PORT,  EPICS_CA_ADDR_LIST and EPICS_CA_AUTO_ADDR_LIST.

If the EPICS parameters are not defined, TChart runs only in "demo" mode.

In addition, the environment variable LD_LIBRARY_PATH must include the direcory where the Channel Access client libraries are located.

If the Channel Access client libraries are not founc, TChart will not start.

Configuration File Options

Note: The configuration file must be manually edited to change these options. They cannot be changed with the configuration dialog (File >> Preferences). 

Archive Directory

TChart uses the Environment variable TRAR_ARCHIVE_DIRECTORY to find the directory where archive files are stored.

Request Directory

TChart uses the Environment variable TRAR_REQUEST_DIRECTORY to find the directory where archive request files are stored.

Data Directories

TChart uses
The user's home directory is the default for all these directories. They can be overridden by editing the configuration file, but not via the File >> Preferences dialog.

Global Configuration File Options


If  a global configuration directory is specified on the command line (see section on Running TChart), the file "tchart_global.cfg" in the global configuration directory is searched for directives to specify the "csv directory",  "registered PV directory", and the "PV case". These global definitions for the csv and registered PV directories  take precedence over the entries in the user's configuration file.
If  a "PV case" is specified, the corresponding radio buttons on the Preferences Dialog will be disabled.

Example of a global configuration file dir.cfg:
# tchart_global.cfg
#
# Global configuration file for TChart.
# The following options are recognized:
#
# global_cvs_directory:
# If present, all saved .csv files are stored there.
# This option overrides the option cvs_directory in the
#   local configuration file.
#
global_cvs_directory c:\tchart
#
# global_registered_pv_directory:
# If present, all saved .pvchart files are stored there.
# This option overrides the option registered_pv_directory in the
#   local configuration file.
#
global_registered_pv_directory c:\tchart
#
# global_pv_case:
# If set to upper or lower will convert PV
# names to the selected case. Any other setting will maintain
# the PV case.
# If this option is present, the corresponding radio buttons
# on the Preferences Dialog will be disabled.
#
global_pv_case upper
#