Contemporary Control Systems AI-FR Redundant Fibre Hubs - Manual (Page 7)

TD675300-0ID
7
LED Indicators
There are several LEDs on the AI-FR which indicate network operation and
help problem diagnosis:
ACITIVITY LEDs 1, 2 and 3
Just above the local drop connectors are three numbered LEDs which
indicate ARCNET traffic is being received on the respective ports. (Port
transmissions do not light any LEDs.) The brighter the LED, the greater its
port traffic.
STATUS (green)
Properly powered and connected but with no valid ARCNET activity on any
port, this LED will flash at a periodic rate in the idle condition. When lit
continuously, this LED indicates that ARCNET traffic is being received and
faithfully regenerated to the other ports on the hub.
RECON (yellow)
As nodes enter or leave the network, this LED will flash to report a routine
reconfiguration of the network. Reconfigurations are not sensed, but
assumed when no data has occurred for 82 ms. Reconfiguration takes a
fraction of a second, but the LED glows for one second for ease of viewing.
Occasional flashes are normal as automatic reconfigurations take place, but
a constant or frequently flashing LED could indicate a faulty network
interface module; defective cable; duplicate node IDs; or excessive electrical
interference.
Troubleshooting with LEDS
ACTIVITY LED fails to light: This may indicate the cable is disconnected
or open, the cable is attached to a defective node, or the hub port is bad.
Test the hub port by swapping its cable with another cable attached to a port
known to function properly. If the symptom follows the cable, the port is
good and a node or cable problem is indicated.
ACTIVITY LED glows excessively: A “chattering node” (one with a
defective receiver) causes continuous reconfigurations. The AI-FR indicates
a bad node by a bright ACTIVITY LED (other port ACTIVITY LEDs will
be dim) and a constantly lit RECON LED. Detaching the cable associated
with the bright LED will extinguish the RECON LED and return other port
ACTIVITY LEDs to normal brightness, thereby confirming the defective
node.
STATUS LED fails to light despite receiving valid ARCNET traffic: This
indicates a defective AI-FR hub.