Different behaviour of the binary FBoxes "set high"/"set low" in PG5 2.0.150

FAQ #101489

 

Short summary

• The behaviour of a Fupla program using "Binary set high" and "Binary set Low" FBoxes can be different when built with PG5 2.0.150 compared to the same program built with any other PG5 version (e.g. 2.0.110).
  In order to avoid this problem, please update the SFup Base library to version 2.6.154 or later. This FBox version is available on the support site.
• In order to avoid unwanted behaviour at startup, do not use the "Binary set high" and "Binary set Low" FBoxes to connect to FBoxes containing an initialization part (e.g. the Heavac Init FBox, the "Sasi Extended" or any other "black" FBox). Use a connector with "0" or "1" instead (see screenshot below).

Detailed description
Some years ago the FBoxes "Binary set high" and "Binary set low" have been added to the standard FBox library. These FBoxes have been added for the visualisation of constant definitions of binary values. The aim was to create an identical behaviour of the "Binary Set" FBox and connectors with constant values inside:

• Binary low FBox (not recommended as the FBox "S-Bus IP Ex" contains an initialization part)
  
• Value written to 0 with connector:
  

Differences between the FBox version 2.6.150 (installed with PG5 2.0.150) and other versions

• All PG5 versions other than 2.0.150
  In some special cases it was found that the FBox for initializing had a different behaviour that the connector with a constant inside. This case is during start-up of the PCD. In case the FBox which is connected to the "L" or "H" FBox contains an initialization part (which is executed in the XOB 16), it was possible that the inizialization was not executed correctly (because it was possible that the related flag written to the output of the binary FBox has not yet been written, as the Fupla page is only executed in COBs).
   
• In PG5 2.0.150 (with SFup Base FBox library 2.6.150) 
  A modification was implemented (writing the output of the "High" or "Low" FBox in the XOB 16, to. Unfortunately by implementing this modification another problem arised:
  As the "H" and "L" FBoxes do write their state to the connected Flags during the start-up block, it is possible that e.g. flags which should only be written in sepcific cases (e.g. in a Graftec Step) are written during the start-up of the PCD.
  As this creates different behaviour of programs written e.g. in PG5 1.4.300, it was decided to undo this modification in the SFup base libraray 2.6.154 (and all later versions).
  It is recommended to use the FBox libaray 2.6.154 as this library behaves the same way as e.g. PG5 1.4.300 or 2.0.110.