Measurement Computing DASYLab User Manual - Manual (Page 49)

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5
Controlling Measurements
The data flow and the sequence of the modules in the worksheet determine
the measurement process. You use triggers, input instruments, controllers,
and actions to control the measurement. You use actions to execute module-
specific functions when an event occurs. DASYLab executes these actions in
the background without data channels, unlike other control modules. During
a measurement you can read in, process, and output characteristic values and
text from variables and strings.
A sequence control is a sequence of worksheets that you link via actions. You
use variables and strings to transfer results from one worksheet to the next
worksheet.
Triggering over Control Inputs
Some modules have a control input with which you can trigger
the module or control a function in the module. The control input
is always at the first position in the connection bar of a module
and displays an X with a yellow background.
In the Relay the signal at the control input determines the output of the data
at the inputs. As long as there is a TTL High signal, the relay outputs the data.
The value
0 corresponds to TTL Low and the value 5 corresponds to TTL
High. The threshold between TTL Low and TTL High is 1.5 , which means
that the relay does not output data as long as the value at the control input is
smaller than
1.5 .
The Differentiation/Integration module does not expect a TTL signal at the
control input but evaluates the data signal. You can specify different
conditions for starting and ending mathematical calculations in this module.
Other modules such as Switch, Signal Router, and Select Values use the
signal at the control input as an index to specify the input or the output.