YOKOGAWA F3LR02-0N, User Manual

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A4-15
IM 34M06H45-01E 7th Edition : Aug.30, 2019-00
A4.5.2 LED Checks
After installing modules and connecting fiber-optic cables, check that the modules are
properly connected for communications. There should be no cable discontinuity or
improper connection.
Apply power to the units and perform the following checks.

The RDY (green) LED indicator must be lit
If this indicator is not lit, it may be because the Fiber-optic FA-bus module is not properly
mounted to the base module. Turn off the power and attach the module to the base
module correctly.

The ERR LED indicator must be off
When this LED indicator is on, communications is not allowed.
If the power of the destination unit is off, turn on its power and check whether the ERR
indicator turns off. If the ERR indicator is still on, it may be due to a transmission
channel error, such as cable discontinuity.
For troubleshooting information, see Section A8.3, “Troubleshooting when the ERR LED
is L
it.”