
User Manual
Section 12
GFK-2958L
May 2021
LED Indicators and Troubleshooting
491
Indicator
LED
Status
Recommended action
System Fault
SF
Red: Configuration error, or error in
the network adapter, or error in a
module, or there is a new diagnostic
message
Check that the GSDML file is up-to-date
Check if the configured station setup matches the
actual setup
Read the diagnostic message with the web server
or an engineering tool and determine which
further actions to take
Red flashing: Station in Force mode
Bus Fault
BF
Red: No connection to the fieldbus
Check the fieldbus cable and the PLC
configuration
Red flashing: Configuration error, no
connection to the control unit, or
error in the parameter set
Check the fieldbus parameters and the PLC
configuration
Check that the GSD file is up-to-date
Check if the configured station setup matches the
actual setup
Maintenance
Required
MT
Yellow: Error on the system bus
Check that the modules have been snapped into
place properly
Connection
Link 1
Green: Connection established
between port 1 of the network
adapter and another field device
Off: No connection
Check the connection to the next participant and
the fieldbus cable
Active
ACT 1
Yellow flashing: Data being
exchanged on port 1
Connection
Link 2
Green: Connection established
between port 2 of the network
adapter and another field device
Off: No connection
Check the connection to the next participant and
the fieldbus cable
Active
ACT 2
Yellow flashing: Data being
exchanged on port 2
Input supply
voltage
3.1
Green: Supply voltage for input
current path > 18Vdc
3.2
Red: Supply voltage for input current
path < 18Vdc
Check the supply voltage
3.4
Red: Internal fuse defective
Replace the network adapter
Output supply
voltage
4.1
Green: Supply voltage for output
current path > 18Vdc
4.2
Red: Supply voltage for output
current path < 18Vdc
Check the supply voltage
4.4
Red: Internal fuse defective
Replace the network adapter