No Communication?
- Verify Ethernet cable connected properly (10Base‑T) [g3-fam3tcp | Word]
- Check IP address of PLC and HMI are in same subnet
- Confirm correct port and driver selected
- Ping PLC to confirm network connectivity
- Verify PLC Ethernet module (LE01‑5T or similar) is active
Connection Established but No Data?
- Check correct device/IP address configured
- Confirm correct protocol/driver selected
- Verify PLC memory areas are enabled for access
Intermittent or Dropped Connection?
- Check Ethernet cable condition
- Verify switch/network stability
- Check for IP conflicts on network
- Confirm proper grounding and shielding
Incorrect Data or Values?
- Verify correct prefix (X, Y, I, M, T, C, L, D, B, V, Z, W) [g3-fam3tcp | Word]
- Confirm correct address range
- Check correct data type (bit vs register)
- Validate scaling or engineering units
Timer or Counter Issues?
- Use correct prefixes (TS, TP, TI, CS, CP, CI) [g3-fam3tcp | Word]
- Verify read-only vs read/write fields
- Confirm PLC logic updates values
Write Failures?
- Confirm target register is writable
- Check PLC mode (run/monitor)
- Verify correct data format
- Ensure write permissions are enabled
No Response from PLC?
- Verify PLC powered and running
- Confirm Ethernet module configured correctly
- Check correct IP address entered
- Try alternate network port or cable
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