Beckhoff First Scan Bit [extra Quality] May 2026

Here are the general steps to use the First Scan Bit:

⚠️ If you use Method 1 in multiple tasks (e.g., a fast cyclic task and a slower periodic task), it will evaluate properly for each task's respective first execution loop. beckhoff first scan bit

Network interfaces, serial buffers, or fieldbus master configurations may contain stale data after a restart. Here are the general steps to use the

VAR_GLOBAL bIsFirstScan : BOOL := TRUE; // Starts TRUE when the PLC runtime begins END_VAR Use code with caution. Copied to clipboard bInit : BOOL := TRUE

PROGRAM MAIN VAR bFirstScan AT %Q* : BOOL; // Not directly. Better: fbFirstScan : F_TRIG; bInit : BOOL := TRUE; END_VAR