Beckhoff First Scan Bit File

If you perform an "Online Change" (modify code without full download), the first scan bit does trigger. Your initialization code will not run. To force reinitialization, use Reset or Reset Cold from the TwinCAT runtime.

// 1. Set global output safe state GVL.bEmergencyStop := FALSE; GVL.nMotorSpeed := 0;

: Setting non-persistent variables to a known starting state. beckhoff first scan bit

: Triggering initial requests for external fieldbus devices like EtherNet/IP Beckhoff Information System Function Block Diagram

IF FirstScan THEN // Force all digital outputs OFF myDigitalOutput := FALSE; // Set analog output to 0V/0mA myAnalogOutput := 0; If you perform an "Online Change" (modify code

Have a tricky Beckhoff initialization issue? Share your experience in the comments or contact your local Beckhoff automation partner.

// Last line of the program bFirstScan := FALSE; Use code with caution. Copied to clipboard Why use a First Scan Bit? Initialization Share your experience in the comments or contact

Name the method exactly FB_init . TwinCAT will automatically populate it with the necessary input parameters:

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