Scaler Display program

NSCL DAQ Software Documentation
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CONFIGURATION FILE

The configuration file is a Tcl script with a few command extensions. The extensions provide the ability to associate a name with a scaler channel, and describe how and if that channel should be displayed.

The display is organized into two sections. A tabbed notebook at the top of the user interface provides several pages. Each page is a table containing scaler names, rates, totals and, if appropriate, ratios of rates and totals for a pair of scalers. The lower section is an optional stripchart that shows the time evolution of counting rates in a scaler or the ratio of a pair of scaler rates.

channel

The channel command associates a name with a scaler channel from a data source. The name is then used both to display the channel and to refer to it in other configuration file commands. The form of this command is:

channel ?option...? name channel?.sourceid?

option...

Are options that control how the channel is treated. Legal options are:

-incremental bool: A boolean value which, if true, means that the scaler channel is incremental (cleared after each read). If false, the scaler counts are cumulative over the entire run.
-width nbits: The value is an integer that specifies the width of the scaler channel in bits. All bits in positions higher than this value will be ignored. This is primarily used with some CAMAC scalers read out through some interfaces that put additional bits in positions above bit 23.
-lowlim rate: Specifies a low rate limit for the scaler. If the count rate for this scaler drops below the specfied rate, the channel will show in a low rate alarmed status, if alarms are enabled via the checkbutton on the scaler display screen.
-hilim rate: Specifies a high rate limit for this scaler.

name

Is the name that will be given to the channel.

channel

Is the index into the data source's scaler array in which the counts for this scaler live.

sourceid

If supplied this specifies the source id from which the data comes. If not specified, the source id defaults no source id which is what you get when the data has no body header.

display_single

The display_single command appends a line to a page. The line displays the rates and total counts for a single scaler. The syntax of this command is:

display_single tabname scaler-name

tabname: Is the name of the tab that has the page the line will be added to. Lines are added to the bottom of the page.
scaler-name: The name of the scaler channel (as defined by a channel command) that will be displayed on that line.

display_ratio

The display ratio command adds a line to a page that displays two scalers. In additon the ratio of the rates and totals are displayed. The line is added to the end of the page. The syntax of this command is:

display_ratio tabname numerator-scaler denominator-scaler

tabname: Is the label on the tab that is displaying the page to which this line will be added.
numerator-scaler: Is the name of the scaler that will be the numerator of the ratios.
denominator-scaler: Is the name of the scaler that will be the denominator of the ratios.

blank

Appends a blank line to the specified tab. The syntax of this command is:

blank tabname

stripparam

If no other strip chart traces have been defined, this enables the strip chart. The command also enables the plot of a single trace of the rate of the specified parameter on the strip chart. The syntax of this command is:

stripparam name

stripratio

If no other strip chart traces have been defined, this enables the strip chart. The command enables the plot of a trace that is the ratio of the numerator scaler to the denominator scaler. The scalers are specified by the name they were given in their channel commands. The form of this command is:

stripratio numerator denominator

stripconfig

Sets configuration options for the strip chart. Naturally this is only meaningful if at least one trace is defined via the stripparam or stripratio commands above.

The syntax of this command is:

stripconfig option ?...?

The available options are:

-timeaxis seconds: Number of seconds on the time axis. Note that since the plot is allowed to choose axis labels that are 'natural' you may get slightly something a bit different, for example a value of 1198 will almost certainly be modified to 1200.

EXTENSION POINTS AND API

There are a number of ways to extend the scaler display.

First the scaler configuration file is just a Tcl script with commands added to the interpreter to support defining channels, pages and their contents and strip chart channels. Thus you could add additional functionality via that script.

Second the scaler display program provides for callbacks to user code that is either part of the configuration file or incorporated by the configuration file. A minimal API also allows extensions of that sort to gain information needed for other processing.

Third, variable values can affect the operation and visual display of the program.

Callbacks

There are three callback points defined by the scaler display program. If a user configuration file defines an appropriately named proc it will be called:

UserBeginRun: As the namei implies, this proc, if defined, will be invoked when the scaler program processes begin run ring items.
UserEndRun: Similarly this proc, if defined, is called when the scaler program processes an end of run.
UserUpdate: Called, if defined, when a scaler ring item is processed.

API

A very simple and minimal API provides access to data and objects that make up the scaler program. These are all simple Tcl procs.

getStartTime: Returns the start time [clock seconds] at which the most recent run started.
getElapsedTime: Return the run elapsed time in seconds.
getTitle: Returns the title of the most recently started run.
getRunNumber: Returns the run number of the most recently started run.
getState: Returns the state of the run. This is one of Active or Inactive depending on whether or not the run is in progress. Note that paused runs will appear as Active
getScalerNames: Returns a Tcl list that contains the name of all scaler channels defined.
getRate name: Returns the counting rate of the channel name as of its most recent update.
getTotal name: Returns the total number of counts accumulated in the scaler name as of its most recent update.

VARIABLES

The following variables affect the visual display of the program:

::scalerconfig::normalColor: Background color for channels that are not in the alarmed state. This can be expressed either as a known named color or as an rgb intensity. The default value is white. Note that this and all alarm color definitions must be defined prior to the page definition in which they apply.
::scalerconfig::lowAlarmColor: Background color for channels that are alarming due to a count rate below the -lowlim value. The default value is green. Note that changing the background color of the alarmed channel does not, at this time, affect the tab color for pages containing the channel.
::scalerconfig::highAlarmColor: Background color for channels that are alarming due to a count rate above the hilimi value. The default avale is red. Note that changing the background color of the alarmed channel does not, at this time, affect the tab color for pages containing the channel.