Optelecom 9525AY/SM-FC Installation And Operation Manual page 11

The same cable and the Model 9525AY may be installed into the expansion port of any modem along
the trunk in order to establish a single or double branch from that trunk. Additional branches can be
made off of these branches, etc., without limit.
NOTE: IN ALL THESE INSTALLATIONS, THE TX1/RX1 PORT WILL BE CONNECTED TO THE FIBER
GOING UPSTREAM TO THE CONTROLLER AND THE TX2/RX2 PORT WILL BE CONNECTED TO THE
FIBER GOING TOWARDS THE FAR END OF THE TRUNKS OR BRANCHES.
2.1.2 Daisy Chain Mode with Two Master Controllers (Refer to Figure 3)
WARNING
This configuration may not operate in some systems. In this
Configuration each master will be able to receive polls from the
other master. The User's software must be able to recognize
and ignore such polls. If it cannot, use the TKH Security USA Model
9522 or 9526 dual master, drop/insert modem
With this architecture, master controllers lie at each end of one or two main daisy chain trunks. In this
application the local modems in the "daisy chain" trunk operate in Local Fault Tolerant mode because
the daisy chain operates in both directions. In a two-trunk installation, the Model 9525AY operating in
Master Fault Tolerant mode would be used as the master modems.
In this architecture one master transmits down two trunk fibers via both ports, through all modems in
each daisy chain, to the optical ports at the second master modem. The priority select circuitry in the
receiving modem decides which incoming optical signal to select. The local modems on each trunk will
be 9525AYs in Local Fault Tolerant mode. Each modem can receive data from either master and
transmits to both masters at either end of both trunks. If communication is lost to one master the
modem can communicate with the second.
Unlimited daisy chain branches maybe connected to either trunk.
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