Fanuc Fapt Ladder -
It is vital to understand that Fanuc Fapt Ladder is extinct. Modern Fanuc controls (31i, 32i, 0i-D) use Fanuc Ladder III software on a PC. Here is the comparison:
| Feature | Fanuc Fapt Ladder | Fanuc Ladder III (Modern) | | :--- | :--- | :--- | | Interface | Green monochrome CRT, keyboard arrow keys | Windows 10/11 GUI, Mouse driven | | Editor | On-board CNC only | PC software (upload via PCMCIA or Ethernet) | | Search function | Slow, limited to 1 address at a time | Full text search, cross-reference tables | | Backup format | .TF or .FD binary | .LAD or .LPC (convertible to PDF) | | Current status | Obsolete (1995) | Active, supported | Fanuc Fapt Ladder
If you are upgrading a machine, you must convert the old Fapt Ladder .FD file to a modern PMC format. This requires a specialized conversion service or an ancient DOS computer running FAPT LADDER-III (DOS version). It is vital to understand that Fanuc Fapt Ladder is extinct
Older FAPT Ladder versions allow editing directly on the CNC’s LCD using the MDI keyboard. Newer practice uses a PC running FANUC Ladder Editor, which connects to the CNC via memory card or Ethernet. This prevents accidental on-shop-floor changes. This requires a specialized conversion service or an
The term "Fapt Ladder" actually refers to a hybrid concept. FAPT stands for Fanuc Automatic Programming Tool. It was Fanuc’s proprietary conversational programming language and software interface, designed to run on older Fanuc CNC controls (specifically the System 6, 11, 15, and 16 series).
The "Ladder" aspect refers to Ladder Logic, the graphical programming language used to program Programmable Logic Controllers (PLCs). Inside a Fanuc CNC, the PMC (Programmable Machine Controller) uses Ladder Logic to handle M-codes, T-codes, safety interlocks, and coolant control.
Fanuc Fapt Ladder is not actually a software you can buy today. It is a specific environment within the legacy Fanuc FAPT software where the programmer could visualize and edit the sequence programs—the ladder logic that told the machine how to behave outside of the G-code movements.