or outputs illegible
characters.
configuration software.
The serial port is not configured
correctly.
Check that the parameter configuration of the serial
port matches that specified in the instructions.
The RJ45 port is not in
connectivity or it is
erroneous in
receiving/transmitting
frames.
The connected twisted pair cable is
faulty.
The length of the cable exceeds 100 m.
The port has special configuration that
has no common working mode with the
connected switch.
Replace the twisted pair cable.
Check that the port configuration has the common
working mode with the connected switch.
The fiber port cannot
be connected.
The Rx and Tx ends are connected
reversely.
The interconnected optical module type
does not match.
The fiber type is not correct.
The length of the optical fiber exceeds
that rated of the optical module.
Switch the Rx and Tx ends of the optical fiber.
Replace the optical module with one of the
matched type.
Replace the optical fiber with one of the
appropriate type.
Replace the optical fiber with one of the
appropriate length.
