Installation manual

Duet2 D2600 / Duet3 D2650 Installation Manual – EU-D2600-D2650-INST/A10/v1 - 13
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12. NVM Programmable Options
Please refer to the Duet’s NVM specifications, being the definitive reference on the NVM programming
details. The maximum call log size, using 93C86 NVM, is 63 events.
13. Engineer Receiver Function
An engineer receiver function exists in the Duet whereby it can receive calls on the GSM network,
handle them as if they came from an alarm control panel, and put them into the NVM for further
processing. (Normally this would be to send them out on either or both of the SMS channels).
The GSM receiver function can be enabled in the NVM System information screen.
Note: If this function is selected, then the corresponding function 5.7 will be disabled.
14. Aerial Siting
The aerial should be mounted vertically at the point of strongest signal. This is usually the highest
point in the building (often the loft area). ALWAYS do a site survey to find the area of strongest signal
before installation.
Large metal structures can affect radio signals. Avoid installing the aerial directly under metal roofs
or within metal-skinned buildings because this will reduce the signal strength and may inhibit
operation completely. If this is unavoidable, the strongest signal will be found away from the metal
roof or close to large external windows or skylights.
Avoid installing the aerial close (2 metres) to cable runs, ducting, structural metalwork, metal pipes,
water tank, electronic equipment, e.g. photocopiers, fax machines etc. These can have similar effects
as metal roofs.
The signal strength LEDs on the Duet (see Fig 1 and 2 and Appendix 1) will give an indication of
signal strength that the unit is receiving from the GSM Network.
Note: These LEDs will not work with GSM and SMS disabled in NVM.
1. Green On High signal strength
2. Red and Green On Medium signal strength
3. Red On Low signal strength
Reliable operation is unlikely with low signal strength. If the LED shows that the signal strength is low,
you should improve the signal strength. This may be achieved by repositioning the aerial. The GSM
aerial lead should not be cut or extended, therefore repositioning the aerial may require that the Duet
is also repositioned.
You can use a Duet, aerial and fully charged battery to survey a proposed site for the point of
strongest signal. Ensure that the Duet is fitted with a SIM Card and NVM and that it is fully operational.
Walk around the site carrying the Duet, aerial and battery observing the signal strength LEDs. When
you have identified the point of the strongest signal, make a note of this point and use it when
installing the aerial.
To identify the best location for the aerial, use the D2366 Test Meter.
You can also use a mobile GSM telephone to show GSM signal strength. The signal strength indicator
is normally a bar or line at the side of the display on the mobile telephone.
Note: The GSM mobile telephone MUST use the same GSM network as the Duet’s SIM card uses. A
portable GSM telephone that uses a different GSM network will NOT show the correct signal strength.
There are often two or more separate GSM networks provided by different Service Providers. In the
UK, GSM networks are operated by Vodafone, O2, Orange and T-mobile.
Remember: It is always easier to find the point of strongest signal before the equipment is fitted to a
wall. Moving aerials, cables, trunking etc... after installation is wasted time and effort.