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LEDR Series I/O Guide
MDS 05-3627A01, Rev. D
remote—
EIA-530 Operation: Instructs the radio at the other end of the
link to “echo” all of the data it receives. This is an effective way of
testing the entire communications system, including the transmission
path over the air. (In the event of a communications failure with the
remote radio, the message “Remote Error” is displayed, and no loop-
back mode is selected.
T1/E1 Operation: The
remote
subcommand mimics the
ior
subcommand
described below.
rf
—Enables an RF loopback mode. This mode allows testing of the local
radio transceiver’s transmit and receive chain. The receiver is rechan-
neled to the transmitter frequency.
NOTE:
RF loopback testing is a valuable diagnostic tool, but it should
not be considered an exhaustive test of the transceiver. In some
cases, interaction between the transmit and receive
phase-locked loops (PLLs) can occur, causing erroneous
results during testing. Changing the transceiver’s RF output
setting may resolve these problems. Also, in some configura-
tions, insufficient signal strength for RF loopback testing may
exist.
In addition, on all LEDR radios except the LEDR 1400 Series,
the transmit and receive frequencies must be within the same
subband for RF loopback to function.
Variables:
ior—
An abbreviation for “I/O remote”, refers to the remote line loop-
back. Remote loopback port selection is relative to the local port. The
radio link will translate any line mapping to select the correct physical
remote port to loop back, based on the selected local port.
linelist—
Represents a list of local line interfaces. It can consist of a single
line number or line name, a comma-separated list of line numbers or line
names, a range of line numbers (i.e., 1–4), or if linelist is not given all
lines. See
for a list of line numbers.
timeout—
The
timeout
variable may be set between 0 minutes (never time
out) and 60 minutes.
Usage 2:
loopback [inb|outb] [linelist] [on|off] [-u <code>] [-d <code>]
Usage 2 (E1) subcommands:
inb
—Refers to the inband loopback configuration.
outb
—Refers to the outband Extended Super Frame (ESF) loopback
configuration.
FT1