Cable Ledger — how the math works

The app is a planning and tracking tool. Each section below gives the rule, the defaults and the standard it follows, so you can check any result by hand and know where a real job may differ.

Cable length

The run length is what you measure or read off the plan, from the panel to the outlet. The cable length adds a routing allowance for the up, over and around the plan doesn't show, and the slack left at each end. The outlet slack is the fiber value for fiber cable and the copper value for everything else. A drop with no run length has no cable length: it's left out of the footage and listed in Checks as "No length yet".

Project specs often ask for more slack than the defaults; change them under Job settings → Lengths. Every length is kept in meters and shown in the job's unit: feet as whole numbers, meters to one decimal, rounded half away from zero.

The 90 m check

Under TIA-568, horizontal cable (the permanent link) is at most 90 m (295 ft); the channel can be 100 m, which includes the patch cords. The app checks the cable length, because the slack loops are part of the cable between the terminations.

Only copper is checked: fiber, coax and other cables never are. The check shows on the drop's row, in the editor, in Checks, on the pull sheet PDF and in the as-built CSV's "Length check" column. Example: a 300 ft run with the defaults is 300 × 1.1 + 10 + 1 = 341 ft (104 m), over; a 240 ft run is 275 ft (84 m), near.

Cable to order

For each cable product, the app counts the drops that have a length and shows the number of drops, the total cable length, the longest drop and the boxes. Boxes are packed by first-fit decreasing: sort the drops' cable lengths from longest to shortest, put each in the first box that still has enough cable, and open a new box when none has. Each drop is one piece of cable, so a drop never comes from two boxes.

• A drop longer than a box can't be packed. It's listed under "Longer than a box": it needs a bigger reel. It still counts in the footage, not in the boxes.
• A product with no box length is ordered "Cut to length", with no box count. Fiber is cut to length by default; Cat5e, Cat6, Cat6A and RG6 come in 1,000 ft (305 m) boxes by default, which you can change under Job settings → Cables.
• What's left in each box, and the total, is shown and never goes below zero.

Example: seven Cat6 drops at 1,408 ft of cable in all pack into 2 boxes of 1,000 ft with 592 ft left over. It's a planning number: crews who pull from several boxes at once end up with different leftovers.

Labels

Each drop gets one label, for both ends of its cable: the outlet and the panel port. TIA-606 has each end of a cable marked. A label is built from a template of text and tokens:

{port:3}, {drop:N} and {seq:N} pad to at least N digits (1 to 6): D{seq:3} gives D007. For {port} the width is the larger of N and the panel's own, so every port on a panel has the same width.

TIA-606-A's horizontal link identifier is fs-an: f the floor, s the letter of the telecom space, a the patch panel (one or two characters) and n the port (two to four digits), so 2B-B23 is panel B, port 23, in telecom room B on floor 2. Later editions add rack and cabinet identifiers for bigger systems, and real project specs vary (one city's spec marks outlets 110-1A01: room 110, rack 1, panel A, port 01), which is why the template can be edited.

• A label is missing (shown as "—", listed in Checks with the reason) when the template reads a port and the drop has none, when it reads a closet and none can be found, or when the template is empty.
• An unknown token, such as a typo, stays in the label as typed, and the scheme editor says so.
• A drop's own label replaces the scheme's label for that drop.
• Duplicates (the same label on two or more drops, ignoring case and outer spaces) are marked in red and counted in Checks.
• Labels never change by themselves. Drop numbers and sequence numbers are given once, only go up, and are never reused. A label changes only when you change something it reads. When a label differs from the one recorded as printed (by a labels CSV share you confirmed, or by marking the drop Labeled), Checks lists it under "Labels changed since printing".

Progress

Each drop has five steps: pulled, panel end, outlet end, labeled, and tested (which counts only when the test is Pass). A drop is done when all five are.

A job with no drops shows 0 percent. Rooms show "4 of 6 done"; steps show "Pulled 48 of 60". A failed test marks the row red, and the drop stays not done.

Checks

Checks is a list of eight lines, each with a count and each a tap away from its drops; a line at zero is hidden, and when every count is zero the job says "All clear". The Job screen's Checks row counts the drops behind at least one line.

1. Over 90 m
2. Within 10 percent of 90 m
3. No label yet (with the reason: no port, or no closet)
4. Duplicate labels
5. Labels changed since printing
6. Failed tests
7. No length yet
8. Longer than a box

The files

Pull sheet PDF. By room: a heading per room ("101 · served from 1A · 4 of 6 done") and a table of Label, Location, Cable, Length, Port and the steps, with empty boxes for the crew to tick and ticked boxes for steps done; lengths over 90 m print in red with ▲ and near ones in orange with △, so neither relies on color alone. By closet: every port of every panel in order, empty ones included, then the drops with no port. Letter or A4, in the language you pick, with "Page 2 of 5 · Cable Ledger" on every page.

As-built CSV. One row per drop in room order: Label, Room, Location, Cable, Kind, Run length, Cable length, Length check, Closet, Rack, Panel, Port, the five steps as Yes or No, Test, Tested length and Notes. The headers are always English, so one spreadsheet fits every job; numbers use "." for decimals and no grouping; the file is UTF-8 with a byte-order mark, CRLF line endings and RFC 4180 quoting, and a cell that starts with =, +, - or @ gets a leading apostrophe so a spreadsheet doesn't run it as a formula.

Labels CSV. Label, End (Panel or Outlet), Room, Location, Cable, Closet, Panel, Port: one row per label end, or one per drop. Drops with no label are left out and the sheet says how many. No formula guard, because label software would print the apostrophe.

Every export is named for the job, the export and the app ("Suite 200 - Labels - Cable Ledger.csv"), so no two overwrite each other.

Where the real world differs

• Lengths: a run measured off the plan misses what the ceiling hides; the allowance covers the usual, not the surprise. Measure along the route when you can, and set the allowance to 0.
• The 90 m check is a planning figure on the cable length. The certifier's permanent-link test is the word.
• Boxes: the count assumes one drop per cut and no waste at the box's end; a crew pulling from several boxes at once lands elsewhere.
• Labels: the app follows TIA-606's style, not every edition's every rule. Match your project's spec with the template.

Sources

• TIA-568: the permanent link (90 m) and channel (100 m) limits for horizontal cabling.
• TIA-606-A and later editions: the horizontal link identifier fs-an and the rack and cabinet identifiers.
• BICSI Telecommunications Distribution Methods Manual (TDMM): the slack recommendations in the telecom room and at the outlet.