Meinberg FDM509 - Manual (Page 7)

7
Mains Socket Power Line (optional)
The power line frequency to be monitored may be connected to the module via this
optional power socket in the front panel instead of the rear VG edge connector. The
power supply for the FDM509 occurs not via this applied mains voltage but via the
rear edge connector (+5V). To detect the mains frequency of 45 ... 65 Hz correctly the
voltage of the connected mains must be in the range of 70V ... 270V AC. This input is
protected by a 200mA slow blowing fuse.
Installation FDM509
Power Supply
FDM509 requests only one single supply voltage of +5V, connected via the rear edge
connector of the module. The current consumption is about 180mA.
Input Signals
For operation of the frequency deviation monitor FDM509 the following input si-
gnals, provided by a preconnected reference, are necessary:
a) 10MHz oscillator clock, TTL level, rear edge connector pin Z12
b) pulse per second PPS, TTL level, rear edge connector pin D6
c) time string (RS232), rear edge connector pin B10
A GPS receiver GPS167 or a DCF77 radio clock PZF509 can be used as a reference,
for example.
Powering Up the System
If all the input signals, the power supply and the power line to be monitored have been
connected, the system is ready to operate. The Fail LED as well as the REF Time LED
and the PL Time LED are switched on after power up reset. FDM509 waits for the
incoming serial time string via COM1 to initialize the internal system time (REF
time). After this is done the PL time is also initialized with the REF time. From now
on the REF time is incremented with the PPS applied while the PL time is incremented
by a certain number of recorded mains frequency periods (50 or 60). The REF Time
LED and the PL Time LED start toggling once per second corresponding to their time
base. The Fail LED is switched off.