Westermo LD-64F - Manual (Page 3)

13 6073-2001
Description LD-64F
LD-64F offers redundant fibre optic communication on RS-422/485 in a multi-drop
network. LD-64F is a high-speed version of LD-64 and data rates from 500 kbit/s
up to 1.5 Mbit/s is possible.
Both multi mode and single mode fibre versions are available. All fibre optic connections
are of the ST-type. Plastic fibre can be used for very short distances (<20 meters).
The maximum transmission distance is calculated from the available power budget of
the modems and the attenuation of the cable, splice joints and connectors. Distances
up to 25 km can be reached using single mode fibres.
The LD-64F is arranged in a master slave configuration with the fibre both starting and
finishing at the master unit. Only one master can be configured on a loop at any time.
There are two F/O channels on each unit, each with a separate transmitter and receiver.
The front cover has 7 LED’s to indicate the state of the various communication paths.
The LD-64F is equipped with a redundant logic system which will control the flow of the
data during fault conditions. If a break is detected on a fibre or a pair of fibres the data
will be re-routed through channel 2. This operation will take approximately 4 ms.
All data in this 4 ms will be lost and will need to be resent.
As with all other Westermo products the LD-64F provides a high level of galvanic
isolation on the power supply side through transformers and also on the alarm side
through optocouplers.
All the operating parameters are set-up via DIP switches located under the lid on the
top of the unit.
Indication and alarm outputs are provided at the master and at the slaves either side of
the fault. the indication and alarm outputs will continue to operate as long as the fault
persists.
The LD-64F is available in a variety of supply voltage in both AC and DC.