Commissioning
2
0
1
5
-0
5
23
In such arrangements, disconnecting one side of an optical data coupler is not
permitted. Similarly, the light beam must not be obstructed.
Parallel Arrangement with VDM100 Distance Measurement Devices
The optical data coupler and distance measurement devices of type VDM100 can
be arranged in parallel. A minimum distance between the devices is not required.
6.2
Topology
The optical data coupler does not contain any address routing logic (switch). This
means that the distribution of the information must always be controlled by an
external switch. The internal Ethernet adapter is permanently set to 100 MBit full
duplex, as this is the only format that is converted for the optical transmission. Any
adjustments required to connection modes must be made using the external
switch. The pair of optical data couplers effectively replace a cable, the maximum
cable lengths always relate to the distance from the ODC to the appropriate
switch. The signal propagation time, on the other hand, depends on the physical
distance between the two ODCs; it amounts to 3.3 ns for each meter of light path.
Figure 6.8
Topology
VDM
100
F1
F2
Light spot of transmitter
Reflector
F1
F1
F1
F1
F2
F2
F2
F2
Switch
stationary
Vehicles
