PROGRAM Example VAR FirstScan : BOOL; END_VAR
BEGIN IF FirstScan THEN // Execute initialization code here // e.g., set default values, initialize variables FirstScan := FALSE; END_IF beckhoff first scan bit
In TwinCAT 3, the First Scan Bit is represented by the system variable FirstScan . Here's an example of how to use it in a simple PLC program: PROGRAM Example VAR FirstScan : BOOL; END_VAR BEGIN
The First Scan Bit, also known as the "First Cycle Bit" or "Initialization Bit," is a special bit in Beckhoff PLCs that indicates when the PLC is executing its first scan cycle. In other words, it signals that the PLC is starting up and executing its program for the first time. PROGRAM Example VAR FirstScan : BOOL