User`s guide

LONWORKS FTT-10A Transceiver User’s Guide 2-11
FTT-10A
Transceiver
Two-Way
Repeater
Network
Segment
2
Network
Segment
1
FTT-10A
Transceiver
FTT-10A
Transceiver
FTT-10A
Transceiver
FTT-10A
Transceiver
FTT-10A
Transceiver
Network
Segment
1
Network
Segment
2
Network
Segment
3
Network
Segment
N
N-Way
Repeater
Figure 2.5 Two-Way and N-Way Repeaters
A repeater consists of two or more transceivers, a 5MHz clock source, and
miscellaneous components. Figures 2.6 and 2.7 show schematics for two-way and
N-way repeaters, respectively. The clock oscillator requires CMOS output levels,
±200 ppm total accuracy (use only a crystal-controlled oscillator; do not use a
ceramic resonator-controlled oscillator), and duty cycle between 40/60 and 60/40.
The OR gate in figure 2.7 requires CMOS output levels and 100nsec maximum
propagation delay. Different clock sources may be used for each of the FTT-10A
transceivers in a physical layer repeater. However, the clock sources must be
synchronized. No ESD snubber diodes or capacitors are shown in figures 2.6 and
2.7 because the FTT-10A transceivers (without accompanying Neuron Chips) do not
require them. Resistors R1, R2 and capacitor C5 shown in figures 2.6 and 2.7 are
required for proper repeater operation. The operating temperature range of these
circuits is 0 to +85°C.