Generalised view of
LB-5A PCB Showing
Connection Details
It is strongly recommended that when installing a unit that is configured as described
opposite and is tested using the supplied memory stick which has been loaded with
different audio files in each of the 15 locations. This will help in testing the installation
and diagnosing any wiring problems. It will also prevent the installer being misled
by incorrectly loaded or wrongly named files which the unit will not play and simply
ignore.
If you require any guidance regarding the above or need advice on other
wiring arrangements please contact our Technical Support department on
T. 0115 9770075.
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Operation:
• Full Operation:
This section describes how to configure the LB-5A unit to access all the
audio files in the three different banks, giving a total of 15. This section also
includes sub-sections which describe the set-up and installation additional
features that can be used if required.
The main difference between this section and the last is the configuration of the
switches. In its basic configuration all that is required is a simple contact closure
as the ‘message’ bank is permanently selected by means of a shorting link. In full
operation, however, this bank selection, along with the other two banks, has to be
incorporated into the switching arrangement. There are several ways of achieving
this but the way to be described, and possibly the most flexible, utilises double pole
switches (i.e. each switch has two contact closures, to activate the required file).
A diagram showing this arrangement is shown opposite...
A way of understanding how this works is to visualise the five switches described in the
previous section but replicated two more times to form three banks of five switches.
One bank will be used to activate the files in the Message group, the second the
files in the Tone group and the third those in the Chime group. A single switch from
each bank has one set of its contacts wired to the same set of contacts on the circuit
board, so SW1 will have three switches connected to it, SW2 another three switches,
etc. This wiring arrangement allows one switch from each bank to activate the same
file number from any of the three file groups e.g. Message1, Tone1 or Chime1.
All that remains is for the switch to select which particular file group the file it is to
activate belongs to. For example, one of the three switches connected to the SW1
contacts needs to be able to specify whether it is to activate Message1, Tone1 or
Chime1. This is achieved by using the other set of contacts on the switch. These
contacts on all of the five switches in a particular bank are connected in parallel and
wired back to the required group select contacts on the circuit board, i.e. ‘Message
Select’, ‘Tone Select’ or ‘Chime Select’ as appropriate.
This means that any one switch will carry out two operations when it is pressed. It will
use one set of contacts to select a particular file number by shorting the terminals
on SW1, SW2, etc and it will use its other set of contacts to select a particular file
group by shorting the terminals on ‘Message Select’, ‘Tone Select’ or ‘Chime Select’.
So, for example, if a switch is required to play the file ‘Tone3’ it will have to short out
the terminals on ‘SW3’ and ‘Tone Select’.
The remainder of the connections to the unit for the power supply and audio remain
the same.
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