INM 937x-FB2-Px-SS Rev 1
18
6
TROUBLESHOOTING
The Fieldbus Barriers inside the enclosure are fitted with LED indicators to assist the
user in fault identification. Consult the following tables to understand the meaning of
the LED states.
Power LED (Green)
ON
OFF
Trunk power applied
Insufficient or no trunk power
CAUTION!
THE POWER LED WILL NOT LIGHT UNTIL THE VOLTAGE AT THE BARRIER HAS
RISEN TO A VALUE OF AT LEAST 15.7V, BUT COULD REMAIN LIT EVEN AFTER THE
VOLTAGE HAS DROPPED TO AROUND 13.0V. DO NOT ASSUME THE POWER LED
INDICATES A VOLTAGE OF 16V OR MORE.
If the green Power LED is not lit, check:
• the polarity and integrity of the trunk cable connections to the enclosure.
• that the d.c. supply powering the incoming trunk is operating correctly.
Spur LEDs
ON
ON
ON
Green
Steady
Channel powering spur, spur OK
Green
Flashing*
Channel powering spur but spur open circuit
Red
Steady
Short to shield on one or more spurs
Orange
Flashing*
Spur short circuit, or spur in current limit state
* Flashing occurs at a rate of approximately 2 pulses per second.
CAUTION!
937X-FB2 FIELDBUS BARRIER ENCLOSURES ARE DESIGNED TO OPERATE
RELIABLY IN INDUSTRIAL ENVIRONMENTS AND COMPLY WITH INTERNATIONAL
STANDARDS FOR IMMUNITY TO ELECTROMAGNETIC RADIATION. HOWEVER,
DAMAGE MAY OCCUR IF THE APPARATUS IS EXPOSED TO EXTREME LEVELS OF
RADIATED ELECTRICAL NOISE, FOR EXAMPLE FROM “WALKIE-TALKIE” RADIOS,
OR ELECTRIC ARC-WELDING. IF LOCAL WELDING ACTIVITY IS UNAVOIDABLE,
POWER SHOULD FIRST BE REMOVED FROM THE FIELDBUS BARRIER.
