Can a DFB be disabled in Concept


Thread Starter

Steve Trupiano

I have written testing simulation DFB's with structured text. One of these does an initialation, which afterwords I want the MMI to be able to write to the tags. The DFB seems to continuously over write with the last state even though the structured text inside skips over it all.

Can I disable the DFB like one would enable /disable a function block?


Jonathan P Blanchard

Like any other function block in Concept a DFB can also be disabled. Double click on the DFB while it is placed in your Concept project. A screen will appear displaying the properties of the DFB. One of the options is to check "Show EN/ENO". Check this option and click OK. The DFB will now have a EN pin on the input side of the DFB and a ENO pin on the output side of the DFB. When the EN pin is a logical 1, the DFB will execute. Otherwise it will not solve in logic. The ENO pin simply mirrors the state of the EN pin.

John Fuhrman

Yes. You can do it in exactly the same way. In Concept (not ConceptDFB), locate the dfb and double-click on it. From the dialog box that appears, check the "show EN/ENO" box. After you click on OK, The EN input will be at the top of your black and the DFB will only process while that input is on. Want more? You can also place the dfb in its own section (or along with other logic) and then use logic in a different section to turn on the "sectionname.disable" variable to diable the entire section--turn it back on to re-enable the section.