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Elementy systemu domofonowego
2500
8. Abnormal operation of the system.
During many years observation of the installed systems only a few types of incorrect
operations have been noticed by the manufacturer. In most cases incorrect operation
was not caused by faults of the system but resulted from errors made by the wireman
during installation of the system. Typical errors are described below.
8.1. Errors resulting from incorrect installation or programming of the
uniphone.
During the uniphone installation and programming, special attention should be paid
to correct installation of jumpers. When two uniphones are programmed with the
same number selection of this number on the keypad results in simultaneous
response of both uniphones. Both uniphones ring and it is possible to have a talk
from any of these two uniphones.
Irrespective of amplification factors set in the talking circuits, excitation of the cassette
can occur, making impossible to have a talk. Furthermore, especially when both
handsets are removed from their cradles, it is impossible to unlock the catch in the
street-door. This response of the system is correct and does not indicate its fault.
It is troublesome to find uniphone producing interference but
to find it is the only way to restore correct operation of the system.
8.2. Call signal fails to operate.
If the call signal fails to operate and entered number disappears from the display
after 3 seconds, the fault can be caused by interference of unauthorized person in
the system. It sometimes happens that the wireman's personal code becomes
known to an unauthorized person who interferes in
the system, e.g. setting times in procedure P-2 to zero or making unnecessary
range shift. Before replacement of the door phone check always if parameters of
the system operation have been set Êorrectly. The wireman's code must be kept
in secret. Very simple combinations of digits. e.g. 0000 should not be used. After
possibility of redefining the code table using procedure P-6.
The above remarks apply also to the case when the catch fails to operate without
evident reasons for this malfunction.
8.3. Troubles with number input.
If problems with the number input occur, make sure that the keypad is not dirty
(water, paint, etc. spilled on the keypad). Dirty keypad may be a cause for
disappearance of one of infrared beams. To check the keypad operation, enter
procedure P-2-9-4 enabling message ¬Ea to be displayed . In spite of special
program capable of detecting and overcoming such defect, some problems with the
number input may occur, particularly when the keypad is operated slowly. A simple
method for checking operation of the infrared system of the keypad conists in an
attempt to keyüin lock code for number 208. This number activates the greatest
number of the display segments so the operation conditions of the infrared systems
are the most difficult ones (due to the supply voltage drop). This test should be
preferably made in darkness. If number 208 can be entered without any trouble and
then the keypad response to the touch on î is correct (horizontal dashes are displayed),
the infrared system operates correctly. Any troubles with the number entering,
appearance of message Err for a moment or delayed response to the field indicate
faulty keypad.
