Functional Description - Optelecom 9522A Installation And Operation Manual

Functional Description

The TKH Security USA Model 9522A is an RS232, RS422, and RS485 compatible fiber optic standalone modem
with dual electrical I/O ports and dual optics for drop and insert applications that can be configured in a wide
range of poll/response network architectures. The unit operates using only one fiber for transmit and receive
in the upstream direction and a second fiber in the downstream direction. This results in the formation of a
single fiber daisy chain or loop.
The units have four switch-selectable modes of operation: Master Fault Tolerant mode (MFT), Local Fault
Tolerant mode (LFT), Master Daisy Chain mode (MDC), and Local Daisy Chain mode (LDC). See the
Installation section for a complete description of these modes of operation.
Each modem has two full function data I/O ports (Primary and Secondary), allowing it to serve two terminal
units at a single location without the need for a second modem. Each of these ports can also interface with
another modem to establish branches off the main trunks or even off other branches. The modem has a
unique feature in that it is able to tag data originating from it when operating in local mode and separately tag
the data from master and local modems. The result of this feature, which identifies the data source, is that the
master only receives data from the locals and the local only receive the data from the master.
The units have ten LED indicators. Power and various fault and status indicators provide information on the
electrical status of the I/O ports, fiber status, redundant ring status, and other possible conditions. A built-in,
offline Bit Error Rate Test (BERT) with indicator LED can help troubleshoot the system. Six of the indicators
serve dual functions as selected by the SELECT switch. In one position the LEDs indicate electrical side signal
activity and CTS status. In the other position the LEDs indicate fiber port activity as well as the active fiber
input port as chosen by the priority select circuitry.
Dipswitches allow the user to select one of the four operating modes (BERT test enable, the communications
interface for each data I/O port, and the timeouts for the optical and electrical side anti-streaming), the fiber
activity CTS inhibit (RS232 mode), the Priority Select Timeout, the electrical Ring Propagation delay, Echo
Cancel, and the "Data Tagging" selective routing feature. These are explained in the Installation section.
The unit operates on 6VDC supplied from the chassis backplane and is compatible with the Network
Management System software for monitoring and troubleshooting TKH Security USA fiber optic transport
systems.
The 9522A modem is optically compatible with the Models 9526A and 9525A standalone drop/insert modems.
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