23
MINUTE IMPULSE Sync System for 2-wire, 3-wire
and Reverse Polarity 1 Minute and 1/2 Minute Impulse
A 24VDC MINUTE IMPULSE Synchronization slave mode may be activated by enabling Function
Fn47
.
SELENA clocks will respond to Minute Pulses within the range of +/- 7 to 30 VDC presented at appropriate inputs.
The current requirement on Line A and Line B inputs are very low and are equivalent to an Input Resistance of 10 Kohm per
input.
Additional functions Fn 11 and Fn 12 can also be set to select a specific protocol for the Minute Pulse sync as follows:
Fn11 Fn12 OPERATION
0
0
58th Minute reference for 2- or 3-Wire system ( Only Line A used by SELENA )
1
0
59th Minute reference for 2- or 3-Wire system ( Only Line A used by SELENA )
0
1
1 Minute Reverse Polarity ( Only Line A used by SELENA )
1
1
1/2 Minute Reverse Polarity ( Only Line A used by SELENA )
Additional Special synch Feature:
Independent of the Fn11 and Fn12 settings, the functions
Fn23
and
Fn13
may also be enabled. This will cause SELENA to
respond to a Negative Synch signal presented on Line B. The protocol will be similar as in the Power Line Carrier Synch
mode. ( see Power Line Carrier synch description ) except that a
Negative DC Signal
is used rather than a specific
Frequency. This may allow the user to independently synch all Selena clocks in the network to the closest hour (58th minute)
and/or to 5:58 if function
Fn14
is enabled and also to 17:58 if
Fn14
is not enabled.
BCD Time Code synchronization Slave / Receiver ( SIMPLEX compatible )
The BCD Time Code Synchronization slave mode may be activated by enabling Function
Fn21
.
SELENA clocks will respond to the signal within the range of +/- 7 to +/-30 VDC presented at appropriate inputs.
The current requirements are very low and are equivalent to an Input Resistance of 10 Kohm.
The input is electrically isolated from all internal electronics via high insulation optocoupler that can withstand high voltage
differences of over 1,500V.
This Sync option can receive BCD Time Code at either 50Hz or 60Hz clock speed and it detects the correct clock
automatically.
MASTER – SLAVE SYNC SIGNAL RANGE EXTENDER – REPEATER
In some installations the sync signal may become deteriorated due to the long distance of wiring or weakening of the RF signal
in RF communication. In such cases SELENA clocks can be set to extend the range by repeating the Master sync signal at
different “Time Slots” than the original Master transmission.
The function
Fn 53
, when enabled, will cause the clock to retransmit the sync signal at various times ( channels ) during each
minute. NOT ALL slaves should be set up with this function enabled. Only a few slaves should have this configuration where
the sync becomes too weak for the slaves farther down the sync path.
The “Repeater” slaves must have the functions
Fn34 and Fn 53
enabled and all other slaves in the system must have the
function Fn 34 enabled only.
To select the retransmission channel the “Repeater” slaves must have the functions Fn54 and Fn 55 enabled as follows:
Fn 54
Fn 55
0
0
sync transmitted at 15th second
1
0
sync transmitted at 25th second
0
1
sync transmitted at 35th second
1
1
sync transmitted at 45th second
NOTE: In the Master – Slave system with Range Extenders the Master MUST NOT transmit all the time. To do that
either the Master PC software must be setup correctly or the Master SELENA clock ( if used ) must have the functions
Fn 32 and Fn 53 enabled and the function Fn 34 disabled. This way the Master will transmit ONLY at the 5th second of
each minute.
