Many developers prefer a manual method for simplicity or for use in older versions of TwinCAT where system structures might differ. This relies on the initialization value of a boolean variable.
A standard Programmable Logic Controller (PLC) operates on a continuous loop: it reads physical inputs, executes user program logic, and updates physical outputs. beckhoff first scan bit
A "first scan bit" is a special internal flag found in most PLCs (Programmable Logic Controllers). It turns for only the very first execution cycle after the controller is powered on or after it transitions from a stopped state to the run state. Once that first cycle is complete, the flag is automatically set to FALSE for all subsequent cycles. Many developers prefer a manual method for simplicity
a global or local variable: bInitialized : BOOL := FALSE; Logic : A "first scan bit" is a special internal
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.