Beckhoff First Scan Bit |top|

The is a boolean variable that is TRUE only during the very first cycle of the PLC program after transitioning from Stop to Run mode [1, 2]. Immediately after that first cycle completes, the bit automatically turns FALSE and remains that way until the PLC is stopped and restarted [1]. Why Do You Need It?

: This bit usually only triggers when the TwinCAT Runtime is started or restarted. Simply stopping and starting the PLC code with the "Start/Stop" commands in the IDE may not reset this bit. 2. Custom Initialization Variable beckhoff first scan bit

Clearing or setting standard function block triggers (like R_TRIG or F_TRIG ) so they do not falsely fire on startup. The is a boolean variable that is TRUE

This ensures a clean, new log file is created each time the controller starts, without overwriting historical data. : This bit usually only triggers when the