13
The power supply unit generates stabilized voltages (± 12 V, 5 V, 3.3 V) needed
to power the device units from the 220 V AC. It also switches to backup DC power
source with (22–30) V voltage.
The power supply unit has a AC 220 V indicator
("POWER"
), an external DC
(22–30) V power supply indicator
("
22 ... 30 V, 35 W"
) indicator and a power
supply unit normal operation indicator ("
NORM"
) which shows the presence of all
output stabilized voltages of the power module.
The front panel group of indicators shows simultaneous presence of signals on
the inputs "
fx
", "
fy
" for each of the eight frequency comparators
("
CHANNEL 1
" - "
CHANNEL 8
"). The indicators are green LEDs turning on and off
at a frequency of about 1 Hz. The front panel also contains the AC 220 V power
indicator and the external DC source indicator.
Indication signal driver generates indication signals and sends them to the front
panel indicators by the processor command.
Power supply and internal information exchange between the device units are
carried out via the signals and power bus. The device units are connected to it in
parallel through the connecting plugs.
3.5.3
Remote control and monitoring
The device is controlled from PC using the special program via RS-232
interface, USB or LAN (Windows only).
The following functions are implemented in the program:
−
receiving and automatic saving of measurement data from the comparator;
−
calculation of statistical functions characterizing the frequency difference
between two signals;
