Specifications

74 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E

S/N Ratio This screen displays the current signal-to-noise ratio in dBm.

Radio Selection This screen is used to set or display the transceiver board selection. When AUTO

is selected automatic switchover is enabled. If a major alarm is detected and a

redundant radio is operational, control will automatically switch to the alternate

radio. The AUTO setting should be used even if there is only one transceiver board

installed. This allows the master station to be easily upgraded at a future date by

simply inserting another transceiver board.

The third line on the display shows which radio transceiver board is currently active.

A selection of A or B forces the active transceiver board to the A or B transceiver

board, and disables standby redundancy. These settings should rarely be used;

they are provided mainly for diagnostic test purposes.

To change the radio selection setting, press the ENTER key, then use the up/down

arrow buttons to select AUTO, A or B. Press ENTER again to make the change.

Transmitter Status This screen displays the transmitter state. “Keyed” means the transmitter is set to

transmit; “dekeyed” means the transmitter is prevented from transmitting. The

transmitter can be keyed or dekeyed by selecting Manual Key from the

Conﬁguration menu (Page 68). This setting is used when working on the radio,

and the radio must be keyed to evaluate transmitter output power.

Show Temperature

and Voltages

This screen displays the radio’s internal temperature and voltages. The input

voltage is the voltage that connects to the transceiver board and is unregulated.

This voltage is essentially the output from the power supply assembly. The output

voltage is read after a 10 Vdc regulator on the transceiver board.

Serial Number This screen displays the serial numbers of the transceiver boards. These numbers

will not match the serial number on the serial number label on the radio. If the radio

is not equipped with a second transceiver board, one of the lines will read “NOT

EQUIPPED.”

Software Revision This screen displays the internal software part number and version number.

SNR, SNR! command, Page 5

RADIO [AUTO/A/B]

command, Page 47

TEMP command, Page 53

SER command, Page 50

SREV command, Page 52