DDE data collection manual trigger

[doejohn44]

Hello,

I'm somewhat new to DasyLab and am trying to design a a monitoring and data acquisition program.

• I was planning on using the DDE Output module to write to an excel spreadsheet.
• I would like to start the global DasyLab program without starting the data aquisition
• Once process variables have reached a satisfactory state, I would like to implement an operator actuated switch to begin data collection. How would I implement this switch?

[DASYLAB_Pro_Retired]

I hope that you were able to figure this out. 

Use a Switch/Relay or Trigger Relay combination to control the data flow to the DDE module. 

You need to be able to define your "satisfactory state" in specific values (absolute value or rate of change of a value) to use the Pre/Post Trigger module. The Combi Trigger offers a different set of conditions. You can use triggers in combination to control the signal that actuates the Relay. 

The Switch module is "Operator actuated" and is a reliable control. You may need to configure the Switch module to use the same time base as the data flow, or, configure it to use "Input" for the timing. Then connect the data to the input of the Switch to have the switch module use the same timing as the data flow. 

Note that if you are using a hardware driver, the data acquisition will start when the worksheet starts. You can then control what you do with that data using controls like the Relay or Latch modules.