Plura RUBIDIUM Series, Руководство пользователя

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Page 24 Functional Description and Specifications RUB SW
2.3 Word Clock Changeover
SW monitors signals received from two word
clock sources.
With the default set-
up (‘ Factory Settings ’ ), the
module operates in the automatic mode , i.e. in
case of any major fault of the active source a
changeover will occur to the other source.
Latching relays are used to switch the 2 x 4
word clock signals, so the signal path does not
change if the module looses power.
'Primary'
Source
'Back-Up'
Source
Changeover
CLOCK
OUT
1
CLOCK
IN 1
- 4
- 3
- 2
- 1
- 4
- 3
- 2
- 1
CLOCK
IN 2
2
3
4
Utilizing one of the configuration tools, you can choose an automatic or manual changeover
operating mode: ‘ Changeover = Automatic ’ or ‘ Changeover = Manual ’ (please refer to
chapter ‘Switcher’: Set -Up the Monitoring and Changeover ).
RUB1 modules offer keys which enable to do a manual changeover at either operating mode.
Two functions are provided (please refer to chapter ‘Keys’: Keys and Lamps, LEDs and GPI ):
•
‘ Changeover to Primary ’ : Changeover to the primary source CLOCK IN 1 . This is the
recommended function, because it avoids any unintentional changeover to the back-up
source.
•
‘ Changeover Toggle ’ : Changeover between sources CLOCK IN 1
↔
CLOCK IN 2 .
Difference between automatic and manual operating mode:
Automatic Manual
Automatic changeover Enabled Disabled
Function of a key:
‘ Changeover Toggle ’
or
‘ Changeover to Primary ’
Failure and error status checked
before a manual changeover:
Changeover only, if the currently
inactive source has not more failures
than the currently active source.
Changeover forced by a
keystroke occurs regard-
less of any errors or
failures.
In the automatic mode, the module tries to output “good” signal s while avoiding any un-
necessary changeover. This leads to a sophisticated changeover characteristic. All the major
errors will be considered. In brief, a changeover to the back-up signal occurs if the primary
input
•
have more ‘ signal loss ’ errors than the back-up signals,
• have errors and the back-up signals have not.
Changeover from the back-up signal to the primary signal works in the same way.
The changeover characteristic
can be modified by setting the ‘ disabled ’ bit for individual major
errors. An error which is not enabled to become a failure will be ignored for the changeover.
This allows you to adapt the changeover characteristic to your application.