The network can be wired as either a Loop or a Radial. If Booster devices are used the system must
be run as a Radial
The maximum cable length before Boosters are used is 1000m.
The Terminator resistors are fitted across the network to smooth out the signal. The network requires
51ohms across pos & neg when checked at any card on the network, this can be achieved by cutting
off or soldering on resistors as required. (See Figs 39, 41, 42 & 43)
On the later version network card this process has been improved by selecting the switches provided
on the PCB for loop topology or radial (bus) and terminator in or out.
NOTE Connection details on the terminal block are not polarity sensitive.
Cable Types
The recommended cable for the network connection between panels is an enhanced cable
manufactured by Draka Cables (Pt No 910234). Screen continuity must be maintained throughout the
entire network circuit including each junction point. This can be achieved in 2 ways,
1. Link the screens through using connector block at each node and drain the screen down to
one point only, generally this method would be used in one building with older Network cards
(fig 36).
2. Connect the screen to the terminal block on the Network card (fig 46) which has a
capacitor/resistor filter circuit. Where the network passes between buildings, screen continuity
should not be maintained from building to building. The screen should be connected to the
earth of one panel in each building.
Where the total network length is greater than 1000m or Network errors are encountered then a
booster device can be used. This means that the network must be wired as a radial and the
terminator resistors set correctly (figs 41 & 42) The Booster works on a supply voltage of 9-35 v DC.
This means that the Easicheck or DF6000 panel external 24v output can power this device.
The Booster has two modes of operation ‘Smart Switch mode’ and ‘Configured Router’, for all
applications we use the former mode. In this mode the device automatically detects the bit-rates of
the connected channel, copies the information detected on the network and forwards it to the next
network card.
Configurations
Network configuration without Boosters - Radial
Fig 43
To Next Page
Loading...
