Test access module (TAM) is the common and standard name given to a fiber-optic coupling element, which is used in remote testing and monitoring applications to combine the OTDR signal with traffic. The device used to perform this function is typically a coupler. Some are broadband-type, others are WDM-type or wavelength-division multiplexers, which are spectrally sensitive combiners.

Optical test access units (OTAUs) are test access units that are used to programmatically connect a fiber under test to test equipment through an optical switching subsystem. This product can create a temporary and low-insertion loss optical path between the test equipment and the fiber when characterizing, troubleshooting or testing any degradation (monitored). OTAUs are designed to be connected to an OTDR, specifically EXFO’s Fiber Guardian, thus allowing a single instrument to test up to 720 fibers in a very dense capacity.

The Node iOLM provides intelligent test automation in addition to being a specialized OTDR for access network testing. Unlike EXFO’s other portable iOLM solutions, the Node iOLM can define and test point-to-multipoint (P2MP) fibers, as well as test downstream from the node or central office to any passive optical network line type. Essentially, what this means is that the Node iOLM can test before and after splitters. It is a node-based, fixed asset designed to expose test resources as web services so it can serve multiple workflows similarly to how a website supports multiple users.

By querying the test equipment with a topology template of the line, the application can define and run a series of OTDR acquisitions. It then assembles the information into a single XML dataset, merging the queried topological information, test results and quality assessment information associated with the discovered elements.