
Appendix B Troubleshooting
© National Instruments Corporation B-5 FBUS-HSE/H1 LD User Manual
Standby state indicates the linking device has passed all self tests and is 
ready to operate. However, it is not functioning because no active Ethernet 
segment is configured.
Operational state indicates the linking device has left standby state because 
the necessary network configuration (if any) has occurred.
H1 Network Status LEDsEach Fieldbus (H1 Network) port on the linking device has an LED to 
indicate the functional states of the port. TableB-3 describes each state.
Flashing red Major recoverable fault
Solid red Major unrecoverable fault
Table B-3.  Description of Fieldbus Network Status LED States
LED State Meaning
Off Fieldbus port is not receiving packets.
Steady green Fieldbus port is alive as Link Active Scheduler.
Flashing green Fieldbus port is not alive as Link Active Scheduler.
Flashing red 
and green
Fieldbus port is seeing traffic, but is at a default or 
visitor address.
Flashing red Fieldbus port encountered a transient, nonfatal 
network error.
Steady red Fieldbus port encountered fatal network error.
Table B-2.  Interpretation of FBUS-HSE/H1 LD Module STATUS LED (Continued) 
LED State Meaning