PLC Splitter Specifications: What to Put in Your RFQ

A specification for plc splitters is only useful if it is unambiguous to someone who cannot see your project. Most disputes on this product do not come from bad manufacturing — they come from a drawing that could reasonably be read two ways, where the supplier read it the cheap way and the buyer read it the expensive way.

This is a practical specification checklist, written around what the standards actually require.

The three specification families you will meet

Suppliers will quote against whichever family your market uses, and the part can usually be built to any of them:

• IEC 61300 — Fibre optic interconnecting devices and passive components.
• Telcordia GR-1209 — Generic requirements for passive optical components.

The mistake is to specify a standard reference without specifying the class or grade within it. If you write only the standard number, the supplier will quote the lowest class that satisfies it. Write the standard and the level you want.

Dimensional data that has to be on the drawing

For this product the critical dimensions are: 1×2 to 1×64 and 2×2 to 2×64, bare fibre, steel tube or cassette format.

Three rules that prevent most dimensional disputes:

1. Give tolerances on every functional dimension, not just the nominal values. A nominal dimension with no tolerance is legally “as the supplier chooses”.
2. Say which dimensions are functional and which are cosmetic. Suppliers prioritise what you prioritise, and they cannot guess.
3. State the gauge or measuring method where a dimension is critical. Two inspectors with different methods will disagree about the same part.

Material and grade

The base specification is silica waveguide chip in a metal or plastic housing with a fibre pigtail. Grades commonly offered include:

• standard grade for access networks
• low-loss grade for long-reach PON
• steel tube housing
• ABS module housing

Ask the supplier to state the grade on the quotation, not on an assumption. Grade substitution is the single most common silent cost reduction, and it is usually invisible in the finished part — a 201 stainless component looks exactly like a 304 one until the second winter.

Surface treatment

The usual finish for this product is not applicable; the quality is in the chip and the coupling, and the housing protects both.

Two points worth writing into the order:

• A measured requirement, not a process name. “Hot-dip galvanised” is a process; “70 µm minimum, tested by coating mass on three parts per batch” is a requirement.
• What happens at cut edges and drilled holes, if any. These are where coatings are habitually broken and where corrosion starts.

Type tests and routine tests

These are different things and are frequently confused in quotations:

• Type tests qualify the design once. On this product: insertion loss per port; uniformity across ports; polarisation dependent loss.
• Routine tests are run on every batch: return loss; temperature cycling.

Specify which type-test reports you want supplied as documents, and which routine test results must accompany each shipment. On a first order, ask for the type-test report before you place it.

The failure modes your specification should be closing

• One port with high loss — a coupling defect on a single channel — a whole-batch average can hide it, so insist on per-port data
• Pigtail breakage at the housing entry — no strain relief where the fibre leaves the package

Each of these can be turned into one line in the specification. That is the real purpose of writing it out: not bureaucracy, but making the specific failure you are worried about somebody’s explicit responsibility.

A specification skeleton you can reuse

1. Scope: PLC Splitter to be supplied as planar lightwave circuit splitter, optical splitter, passive splitter.
2. Dimensions and tolerances: 1×2 to 1×64 and 2×2 to 2×64, bare fibre, steel tube or cassette format.
3. Material: silica waveguide chip in a metal or plastic housing with a fibre pigtail; grade standard grade for access networks or better.
4. Standard: IEC 61300 — Fibre optic interconnecting devices and passive components; Telcordia GR-1209 — Generic requirements for passive optical components.
5. Finish: not applicable; the quality is in the chip and the coupling, and the housing protects both.
6. Tests: insertion loss per port; uniformity across ports; polarisation dependent loss; return loss; temperature cycling.
7. Marking and packing: per-piece bag with test data label; cartons of 20–50 pcs.
8. Inspection: pre-shipment, against this specification, with photo evidence and test records.

Related: the plc splitter quality inspection checklist turns this specification into an inspection plan you can hand to a third-party inspector.