代码 5311: FSSB: ILLEGAL CONNECTION
问题描述与安全警告
Fanuc 16i/18i/21i CNC 触发了严重的 FSSB: ILLEGAL CONNECTION 警报。需要由合格的操作员或维修技师立即处理，以防止在制造周期中对设备造成二次损坏或导致零件报废。在接触电气控制箱之前，请务必确保遵循标准安全和停机挂牌 (LOTO) 程序。
官方故障排除步骤
1. This alarm is issued if, in a pair of axes in which one axis has an odd servo axis number (parameter No. 1023) and the other has an even servo axis number that is adjacent to the odd servo axis number, one of the axes is assigned to an amplifier connected to an FSSB in a system different from that for the other axis. 2. This alarm is issued if the system does not satisfy a constraint for performing high–speed HRV control, current control periods for two FSSBs are different, and it is specified that pulse modules connected to an FSSB in different paths are to be used. ??? BP/S alarm BP/S alarm occurs in the same number as the P/S alarm that occurs in ordinary program edit. (P/S alarm No. 070, 071, 072, 073, 074, 085 to 087) Modify the program.
Source: Fanuc Series 16i/18i/21i-B Operator's Manual, Appendix G Alarm List (B-63864EN/03)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
关于 Fanuc 16i/18i/21i CNC 警报
由 Fanuc 制造的工业控制器具有广泛的诊断系统，用于保护内部电路和机械连杆。当 16i/18i/21i CNC 出现类似 5311 的错误代码时，通常表示指令值与实际传感器反馈之间存在不匹配。
完整报警清单: 360 Fanuc 16i/18i/21i CNC 代码s.
Have a better solution?
Help the industrial community by sharing your repair experience for code 5311.
Need a searchable reference for more Fanuc 16i/18i/21i CNC manuals?
We structure equipment manuals into searchable code, title, cause, solution, safety note, and source-reference data. Send a PDF and example searched codes when you need public pages, private search, or structured exports.
Space reserved for Google AdSense / Industrial Affiliate Links
Monetization target for 2026