CANOGA PERKINS 3240S SNMP Managed Fiber Optic Multiplexer - Manual (Page 83)

3240S F I B E R O P T I C M U L T I P L E X E R
3240S Fiber Optic Multiplexer
Chapter 5 - 3240S Troubleshooting and Repair
5.1 Types of Malfunctions
This section is devoted to troubleshooting failures that could occur when operating a Canoga Perkins 3240S multiplexed data
communications link. If a malfunction occurs, there are normally four possible defective components to consider:
1. Data Sources (i.e., CPUs or peripherals)
2. I/O Cabling
3. Fiber Optic Cables
4. Multiplexers
The intent then, is to isolate the fault to one of these four components. To simplify troubleshooting the communications
system, the four components can be split into two groups:
1. I/O Cabling and Data Sources
2. Fiber Optic Cables and Multiplexers
Typical symptoms that may be observed with I/O cabling or data source malfunctions are data errors on a single channel. It
is unlikely that multi-channel failures could be caused by cabling or data. In the event that multi-channel failures should
occur, refer to the troubleshooting flowchart Figure 5-1a, 5-1b, and 5-1c, to help isolate the problem. Refer to Chapter 2 for the
setting of loopbacks, and Chapter 4 for setting loopbacks via the NMS on managed systems.
To isolate the problem to I/O cabling or a data source failure, the following steps should be taken:
1. Identify the channel with the failure.
2. Interchange the cabling and data sources of the failing channel with a known good channel at each multiplexer (i.e., if
channels one and two are swapped at the local 3240S, swap channels one and two on the remote link as well).
3. If the failures follow the suspected bad channel cable, the errors are caused by the I/O cabling or the data sources. The
exact cause of the failure can be found by further substitution of the cables and data sources. If the failures do not follow
the suspected bad channel, the failure is caused by the multiplexers. If the multiplexers are identified as the cause of the
failures, refer to the troubleshooting flowchart, Figure 5-1a, 5-1b and 5-1c, to determine the defective component.
The second category of failures observed can be caused by multiplexer or fiber malfunctions. Fiber optic cable failures will
cause all channels to malfunction, and failures of either multiplexer can cause partial or complete system failure.
The troubleshooting flowchart is provided for isolating multiplexer and fiber failures. The following equipment is required to
perform all of the tests:
1. Optical Power Meter
2. Fiber Optic Jumper Cable
3. Data Source
The data source may be a test signal that is transmitted and received through the multiplexer, or a bit error rate tester that
generates and receives a test pattern.
5-1