Technical Overview: Fanuc 21i Control
The Fanuc 21i CNC control is a standard-setting system valued for its robust architecture and precision machining capabilities. Achieving reliable RS232 DNC communication and drip-feeding requires strict adherence to asynchronous serial port protocols. Common troubleshooting involves verifying baud rate synchronization, matching stop bits, and resolving handshaking conflicts between XON/XOFF (software) and RTS/CTS (hardware) flow control methods. Mismatched parity settings or improper cable shielding often lead to framing errors or buffer overflows. Our configuration guide streamlines the setup of parameters 0000 through 0103, ensuring a stable, high-integrity data link between your workstation and the machine controller. By aligning your EasyDNC communication settings with these specific parameters, you can eliminate intermittent transmission drops and maintain consistent operational throughput during complex, high-memory drip-feed cycles.
More information about the RS232-Port and the ALARM 086 (DR SIGNAL OFF / READER NOT READY) can be found here
More information about the ALARM 087 (Buffer Overflow) can be found here
| Parameter | Value | Comments |
|---|---|---|
| 0000 | 00000010 | |
| 0020 | 0 | |
| 0100 | 00100000 | |
| 0101 | 10000001 | |
| 0102 | 0 | |
| 0103 | 9 (BaudRate 2400) | |
| 6 = 300 / 7 = 600 / 8 = 1200 / 9 = 2400 / 10 = 4800 / 11 = 9600 | ||
| TV Check | 0 = Disabled | |
| Punch Code | 1 = ISO | |
| Tape Format | 0 | |
| I/O Channel | 0 | |
| Drip Feed: Select TAPE mode on the controller, press 'Cycle Start', and then send the program from your computer. | ||
| Ensure EasyDNC settings match the baud rate, parity, data bits, and stop bits of the control. Mode: 'Auto' or 'Fanuc'. | ||
Cabling and Connection
The cable diagram shown above is the industry standard, supporting XON/XOFF (DC1/DC3) software flow control. If your CNC machine is configured for RTS/CTS (hardware) flow control, please refer to the alternative diagram below, which is designed to accommodate both communication protocols effectively.
