First-scan setup

Load starting values once, then let the program change them.

Step by step

Pick a step. The rungs are drawn by the editor after Core scans the program up to that step.

Global.System_Scan_First

MOV

Source

Dest500

Global.RaisePB

AGlobal.Setpoint500B10DestGlobal.Setpoint500

1. First scan. System_Scan_First is 1, so the MOV loads 500 into Setpoint.

Step	System_Scan_First	RaisePB	Setpoint
1. First scan	1	0	500
2. Scan 2	0	0	500
3. Press RaisePB	0	1	510
4. Release RaisePB	0	0	510

The engine sets System_Scan_First to 1 on the first scan after a reset or a project load, and to 0 on every scan after.
The MOV runs only on that scan, so later changes to Setpoint are kept.

Writing a default every scanWithout System_Scan_First, the MOV puts 500 back every scan and RaisePB seems to do nothing.