The DTA desk call station consists of the following components:
o The three-part grey-white desk housing made of ABS
o The aluminium mounting plate
o The electrical components:
- Gooseneck microphone (standard part for call station with call signal,
mounted in top)
- 4 W/6 W loudspeaker (mounted on aluminium plate)
Motherboard with 4 W call station amplifier (mounted in housing base)
-
-
Keypad circuit board with 30 keys (mounted on aluminium plate)
- Keypad circuit board with 18/36/54 keys (mounted on aluminium plate)
Included with the product are:
-
DTA connecting cable 2.5 m
- Wall connection socket
A 4NSA module is required in the system in order to connect the call stations to the
DVS-21.
The analogue interface module 4NSA is connected to the wall connection socket by
4 or 6-wire cable and configured there according to the corresponding plug contacts.
The DTA connecting cable is plugged into the 15-pin D-sub connector of the DTA
and configured according to the corresponding plug contacts of the wall connection
socket.
The following describes the functionality of the DTA purely as malfunction alert panel,
i.e. without PA/intercom functionality:
Programming is done with the help of the ICS software.
For this a block of keys (the start and end keys of the block are inputted) is
established, which handles a line-on and line-off frame differently than normal line
keys.
If a special model of the DTA is used as malfunction alert panel then the physical start and end
keys can be different than those of the standard model. If a basis housing has more than 30 keys
then it is always a case of a special model. Thus the following applies
(with 36-54 keys in the basis housing): Start key = 31, end key = 66 ... 84
All status changes inside this block (on → off as well as off → on) are indicated
optically by different blinking lights on the associated line key. Also an audio signal
sounds with every status change.
The blinking line keys and the audio signal are a request to the user to acknowledge
the status change event by pressing the respective line key. After acknowledging, the
way the line key is illuminated changes to correspond to the current status of the
change.
If all status changes have been acknowledged then the audio signal goes silent and
is switched on again only when the next status change occurs.
All line keys in a defined block work independently of one another and can be used at
the same time. The audio signal sounds as soon as a status change occurs which
has not yet been acknowledged.
Only when all status changes have been acknowledged does the audio signal go
silent.
All line keys of the DTA call station can be operated simultaneously and
independently of one another and also be evaluated in the DVS-21 central system
simultaneously and independently of one another.
Manual check and self-test:
To check all optical and audio elements a separate key can be defined as lamp and
signal test key.
When the lamp test is activated all LEDs of the line keys are turned on to manually
check the proper functioning of the display elements.
The switching on or off of the display elements using the lamp test only has an effect on the
regular condition of the display elements during the active lamp test function.
It overrides the LED illumination only for test purposes and switches all display elements back to
their original condition after the lamp test is deactivated.
After the call station operating voltage is switched on or after a reset of the DVS-21
central system (at the soonest 7 sec. after switching on) the call station illumination
shows the availability of the key processors in use for 3 seconds.
The number of illuminated LEDs shows here the respective number and the start key
of the keypad block allocated to each processor.
After 3 seconds the motherboard of the DTA call station carries out a preliminary
initialization of all keys. When this happens the illumination of the call station keys,
which indicates availability goes off, and all keys in use are queried in sequence for
100 ms and tested. If this test is not completed successfully or if the start illumination
does not go off then the call station is defective and should be exchanged.
Application example:
Original condition: illumination of all the line keys is in inactive condition
(switched off).
When a status change occurs (on) the LED of the respective line key begins to blink
with a quick rhythm and the audio signal sounds.
The change Off → On is indicated by quick blinking and an audio signal.
The operator acknowledges this incoming signal by pressing the blinking line key.
After that the audio signal goes off and the line key takes on the active status.
The acknowledged line key is now continuously lit and the audio signal is off.
When a status change occurs again (switching off of the previously switched-on line
key) the LED of the line key begins to blink with a slow rhythm and the audio signal
sounds again.
The change Off → On is indicated by slow blinking and an audio signal.
The operator acknowledges this incoming signal again by pressing the blinking line
key. After that the audio signal goes off and the line key takes on the active status.
The acknowledged line key is now not illuminated and the audio signal is off.
All line keys in a defined block work independently of one another and can be used at
the same time. The audio signal sounds as soon as a status change occurs which
has not yet been acknowledged. Only when all status changes have been
acknowledged does the audio signal go silent.
To check all optical and audio elements a separate key can be defined as lamp and
signal test key.