Why might a STEP FOUR mill not move even though the software shows it milling?

In this case, a CNC mill STEP-FOUR Basic 540 or Basic 1000 was used, connected to the manufacturer’s milling software “STEP-FOUR Frässoftware V4”. This software would show the milling process, but the mill did not move at all. I found multiple reasons that can cause this:

• One reason can be that “simulation” mode is chosen in the software. When using the application “STEP-FOUR Frässoftware V4”, this can be recognized by a green blinking field in the program status bar.
• The second possible reason is that the LPT mode configuration of the computer is set to a mode not accepted by the STEP-FOUR motor controller box. To fix this: go into the computer BIOS and set LPT mode to “Unidirectional”, “Standard” or “SPP”.
• The third possible reason is that the parallel port is disabled altogether in BIOS.
• The fourth possible reason is that the I/O address of the parallel port is set to a different value in BIOS than in your milling software (this time, EMC2, not STEP-FOUR Frässoftware V4 as above). At least in EMC2, you need to configure the I/O address in the software. If you use EMC2, set the address to 0x0378 in BIOS, as this is the default used in EMC2 as of EMC2 2.4.3 [source].