1756-PM003H-EN-E, SFC and ST Programming Languages ...

4-42 Design a Sequential Function Chart
SFC_STOP Structure
Each stop uses a tag to provide information about the stop element:
If you want to:
determine when the SFC is at
the stop
determine the target of an SFC
Reset (SFR) instruction
determine how many times a
stop has become active
use one tag for the various
status bits of this stop
Then check or set
this member:
Data type:
Details:
X BOOL • When the SFC reaches the stop, the X bit turns on.
• The X bit clears if you configure the SFCs to restart at the
initial step and the controller changes from program to run
mode.
• In a nested SFC, the X bit also clears if you configure the
SFCs for automatic reset and the SFC leaves the step that
calls the nested SFC.
Reset BOOL An SFC Reset (SFR) instruction resets the SFC to a step or stop
that the instruction specifies.
• The Reset bit indicates to which step or stop the SFC will
go to begin executing again.
• Once the SFC executes, the Reset bit clears.
Count DINT This is not a count of scans of the stop.
• The count increments each time the stop becomes active.
• It increments again only after the stop goes inactive and
then active again.
• The count resets only if you configure the SFC to restart at
the initial step. With that configuration, it resets when the
controller changes from program mode to run mode.
Status DINT For this member: Use this bit:
Reset 22
X 31
Publication 1756-PM003H-EN-E (excerpt from 1756-PM001H-EN-P) - August 2005