Operation; Normal Operation - Fermax MDS-2H Manual De Instrucciones

Decoder MDS-2H
Decoder MDS-2H

OPERATION

• Normal Operation

Once the decoder and the 2-wire telephones connected to it have been programmed the decoder detects the
programmed addresses from among all those circulating in the decoder bus. If this occurs, it will retransmit the command
to the telephone bus, adapting the protocol of both buses. Likewise, it will also transmit to the decoder bus the data
streams that the 2-wire devices send to an MDS Panel or Central.
In standby mode, the decoders isolate the audio from the 2-wire segment connected to it. When a call is made from
the outdoor Panel or Guard Unit to a house with a 2-wire telephone whose address forms part of the set of addresses
programmed in the decoder, it connects the audio to the Panel, setting up communication in this way.
The 2-wire decoder saves at all times the address of the guard unit and the panic call unit where present (both can
physically be one and the same). Note that in order to take full advantage of the potential of the alarm managment
system it is convenient to have a guard unit configured in panic mode. A panic guard unit sets the decoder in day panic
mode, so that the decoder redirects the alarm and tamper warnings to the panic guard unit, where they may be viewed
on the display of said guard unit. If the system is in night panic mode the decoder does not retransmit the alarm and
tamper warnings to the decoder bus. The decoder takes the one set in day mode to be the active guard unit.
• Terminal Number Programming
The decoder is a device that must be programmed. Programming a 2-wire decoder is similar to that of
a conventional audio decoder, the only difference being that the 2-wire device and decoder line are
programmed simultaneously. In this system, the address/number of each 2-wire terminal can be any within
the range 0 - 9999. From this, we can deduce that the maximum number of terminals depending on a
single MDS central unit is 10,000.
It is possible to program a 2-wire decoder-telephone set by means of an MDS digital with display, an MDS City
panel or using DecoWin (See compatibilities table). After programming the decoder, it starts up a cycle programming
the devices connected to it (in this state, the DL1 LED blinks rapidly) and sends the addresses/numbers assigned by
each output. This programs each terminal with its corresponding address. For programming using DecoWin, the
decoder has a 4-way Molex connector, to connect the PC decoder programming Module (Referencia 2466).
If the installer wishes, the 2-wire decoders can be programmed in their workshop, with no telephones connected
(using an outdoor panel or DecoWin), to be installed later, along with the unprogrammed telephones (monitors).
In this case, when a few seconds have elapsed after the power supply has been turned on, all the decoder outputs
(that have been programmed) will be disabled (red LEDs beside the telephone connection terminals ON). At this point,
the decoder can be set to transfer the addresses to the connected telephones, simply by pressing the decoder PGM
button, twice. This makes the decoder start up a programming cycle as described above.
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