How to find the PON port on a box-type optical splitter

The PON port on a box-type optical splitter is the single input fiber that connects to the OLT, usually labeled as "PON," "Input," or "IN," and is often distinguished from multiple output ports leading to subscribers.

Identifying the PON Port

1. Check the Labeling: Most ABS or LGX box-type splitters have clear labels. The PON port is typically marked as "PON," "IN," or "Input", while the output ports are labeled numerically (e.g., 1–8, 1–16) for subscriber connections .
2. Port Quantity: The PON port is usually a single fiber input, whereas the outputs are multiple fibers corresponding to the splitter ratio (e.g., 1×8, 1×16, 1×32), . The input fiber carries the signal from the OLT, and the outputs distribute it to Optical Network Terminals (ONTs) at user premises .
3. Connector Type: Standard PON ports often use SC/APC connectors, which are green and angled, to minimize back reflection. Output ports may use the same connector type but are usually grouped and numbered .
4. Physical Position: In many box-type splitters, the PON input is positioned separately from the output ports, often on one side of the box, while the outputs are arranged in a row or cluster .
5. Documentation or OEM Markings: If the splitter is from a manufacturer like HOLIGHT or FS, the unit may include a port map or diagram showing which port is the PON input and which are outputs .

Practical Tips

• Trace the Fiber: Follow the fiber coming from the OLT; it should connect to the PON port.
• Avoid Confusion: Do not connect the OLT fiber to an output port, as this can cause signal loss or network issues.
• Testing: Use an OTDR or optical power meter to verify the input port if labels are missing or unclear. The PON port will show the highest optical power from the OLT side . By combining label inspection, connector type, port position, and fiber tracing, you can reliably identify the PON port on a box-type optical splitter and ensure correct network connections.