Specifications

MDS 05-3438A01, Rev. E MDS 4790/9790 Series I/O Guide 51
Show Selected
Parameters
SHOW [DC/PWR/CURRENT/RADIO]
The SHOW command discloses different types of radio information,
depending on the command parameter entered. These are:
•
DC—Displays DC input/output voltages.
• PWR—Displays the actual (measured) RF power output in dBm.
Unlike the
PWR command, this command shows the actual level
being measured, not the programmed RF power setting.
•
CURRENT—Shows the low noise amplifier and total board cur-
rent.
•
RADIO—Shows the currently active radio (A or B).
Signal-to-Noise
Ratio
SNR, SNR!
These commands display the signal-to-noise ratio in dB. MDS’ defini-
tion of signal-to-noise is based upon the signal level following equaliza-
tion, for valid data frames only. A valid frame is defined as containing
no more than one bit-error, and belonging to a packet addressed for the
receiving radio. SNR is updated and latched for each valid packet
received. A filter in the DSP tempers the effect of any sudden changes
in the value.
Output ranges from 10 dB to 33 dB. A value of 10 dB represents a weak
or no signal. A value of 24 dB represents a very strong signal.
The
SNR command causes the diagnostic port to enter an SNR update
mode. The
DIAGNOSTIC PORT will display an updated SNR output line
at roughly a 2 second interval refresh rate. The diagnostic port will stay
in this mode until the Enter key is pressed at the PC.
The
SNR! command is a “computer friendly” version of SNR. It provides
a one-time reading and display of SNR at the diagnostic port.
Command Input Response
SHOW DC DC IN xx.x V
DC OUT x.x V
SHOW PWR RF POWER xx dBm
SHOW CURRENT LNA xxx mA
TOTAL xxx mA
SHOW RADIO B RADIO IS ACTIVE
A RADIO IS [INACTIVE|NOT
EQUIPPED]
S/N Ratio screen,
Page 74
A
B