FANUC Alarm PRIO-493 — Modbus Socket Error
FANUC PRIO-493 (“Modbus Socket Error”): The Modbus TCP Server was not able to open and use a TCP network socket. First check: This alarm generally implies that the Ethernet or TCP/IP interface is not set up correctly.
Updated 2026-09-17 · LogrobotLM reference
Description
The Modbus TCP Server was not able to open and use a TCP network socket.
Remedy
This alarm generally implies that the Ethernet or TCP/IP interface is not set up correctly. For example, if no IP address is defined, then the TCP/IP stack cannot initialize. Verify network connectivity using the ping utility (on the robot, and also on the local PC).
Related codes
Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →