ESME-HVAC(M172) set/reset instruction on ST

[StevenCho]

Hi, all🙂

I am looking for set/reset expression on ST language.

I found that machine expert(previously Somachine) support set/reset instruction.

( s= / r= )

But it seems that it is not the ST but ExST.

So I reached this conclusion. "ESME-HVAC don't support set/reset on ST".

Is there any other way to use set/reset instruction on ST?

even similar expression will be helpful.

Thank you! 

[Bastian_Schmitz]

Hello,

Codesys offer this enhancement of the language ST. Regarding to this the most codesys based softwares like ESME or SOM offer also this feature. ESME HVAC is not based on codesys. And it offers in my personal expirence not this feature and not this language extension.

But I did not understand the use case or the advantag of this expression.

[FedericoM]

Hello,

some alternatives to Set/Reset functions in ST are:

Set:

IF <Set condition> THEN

xVar :=TRUE;

END_IF;

or

xVar := SEL(<Set Condiftion>,xVar,TRUE);

or 

SR RS bistable function blocks (Basic Library)

For Reset:

IF <Set condition> THEN

xVar :=FALSE;

END_IF;

or

xVar := SEL(<Set Condiftion>,FALSE,xVar);

or 

SR RS bistable function blocks (Basic Library)