A variable is a symbol that holds and represents a value. Variable symbols are names such as x, MyVariable, or lcd.backlight. Variables can hold numbers (such as 3 or 12.7) or strings (such as Hello World).

CueServer uses two different kinds of variables: User Variables and System Variables. User variables can be any combination of printable letters, numbers, the underscore (_) or hyphen (-). System variables are similar, but must contain a dot (.) character. The dot character is how the CueServer distinguishes between User and System variables.

Assigning Values to Variables

There are two ways to assign a value to a variable. The first is with the Assign command. Here are a few examples:

"x" = 3
"MyVariable" = 42
"Message" = "Hello World"
"y" = ('x' + 3)
"caption" = "Press " + 'y' + " to Start"

The first line assigns the number 3 to the variable x. The second assigns the number 42 to the variable MyVariable. The third assigns the string Hello World to the variable Message. The fourth assigns the result of the expression ‘x’+3 to the variable y. The last example assigns a string made of several smaller strings (“Press “, followed by the value of variable ‘y’, followed by “ to Start”) into the variable caption.

The second way to assign a value to a variable is with the Set command. Here are a few examples:

Set x 3
Set MyVariable 42
Set Message "Hello World"
Set y ('x' + 3)
Set caption ("Press " + 'y' + " to Start")

These examples are the same as above, except that the Set command is used instead of using the Assign command.

Using Variable Values

To use variables in CueScript commands, enclose the variable name in single quotes ( 'MyVariable' ).

For example, using the variable values set from above, the following variable substitutions would be made:

Cue 'x' Go Executes Cue 3
Macro 'MyVariable' Runs Macro 42
Set lcd.top 'Message' Displays “Hello World” on the top line of the LCD
Log 'y' Writes “6” to the System Log
WRITE COM1 'caption' Sends “Press 6 to Start” to the RS-232 port

Using Variable Values as Commands

To use variables values in CueScript as commands, enclose the variable name in accent quotes ( `myCommand` ).

The following example script shows how to assign a string that happens to be valid CueScript to the variable myCommand. On the second line of script, if the variable x is greater than 3, then the commands in myCommand will be executed.

"myCommand" = "Cue 1 Go"
If ('x' > 3) Then `myCommand`

Using System Variables

Special System Variables are used to set the properties of hardware devices, or to change internal behaviors of the CueServer. All system variables include a dot ( . ) in their name, for example lcd.backlight, or universe.priority.

See the section on System Variables for a description of how to use these built-in variables.