Read Completeness Is a Timing Budget

Read Completeness Is a Timing Budget

Ada re-derives this chapter’s own numbers step by step, at full precision

ADA · CALCULATION AUDIT

Read Completeness Is a Timing Budget

A dock-door portal must confirm when a tagged pallet crosses from staging into a truck, and its release test logs both raw observations and the accepted event: 47 raw reads from antenna A, 39 from antenna B, resolving to exactly 1 accepted crossing. The chapter times a forklift moving at 1.2 m/s through the 2 m read zone against a reader that completes one inventory cycle every 120 ms. This audit asks the question that timing budget invites: how many inventory chances does that pallet get before it leaves the field, and how far does that number fall if the forklift speeds up?

Companion to the chapter RFID Hardware Integration — every number here comes from that chapter.

See the relationship before changing it

The figure reads from left to right. The blue card is forklift speed. The middle card applies this page's rule. The green card is inventory chances. Walk the arrows once: set the input, apply the rule, then read the result with its unit.

The retained audit below checks several chapter fixtures. This model keeps those stated values fixed and changes only forklift speed, so the numeric fixture does not switch without explanation.

Walk the arrows. A faster pallet spends less time in the read field and gets fewer inventory chances.

Derive the baseline in four named moves

1. 1

   Name the input. The chapter baseline is 1.2 m/s.

2. 2

   Name the relationship. chances = 2 m zone / speed / 0.12 s cycle

3. 3

   Substitute with units. 2 / 1.2 / 0.12 = 13.9 rounds

4. 4

   Read the result. Keep the unit beside the value. Use it only inside the technical boundary on this page.

Predict, then change forklift speed

Try Predict the direction of chances = 2 m zone / speed / 0.12 s cycle. Test another forklift speed, then compare inventory chances.

Forklift speed

1.2 m/s

Chapter baseline

Inventory chances

Observe A faster pallet spends less time in the read field and gets fewer inventory chances. Reset forklift speed to 1.2 and compare inventory chances.

Explain A faster pallet spends less time in the read field and gets fewer inventory chances.

Check yourself

What should you do before trusting a moved-control result?

Answer: Predict its direction, apply the shown relationship, keep the units, and reset to the worked baseline.

What does this small model leave out?

Answer: Only forklift speed moves here. Field effects named in the technical boundary stay fixed.

Honesty note. This teaching model changes only forklift speed. It is not a field prediction.

TryRecompute Dwell time: a forklift at 1.2 m/s crossing a 2 m read zone keeps a pallet in the field for 2 / 1.2 = 1.667 s.

ObserveTrack Inventory chances: at one useful cycle every 120 ms, that is 1.667 / 0.12 = 13.9, about 13 chances to see each tag — enough for a sparse pallet.

ExplainExplain Now double the forklift speed to 2.4 m/s: dwell halves to 2 / 2.4 = 0.833 s, and chances fall to 0.833 / 0.12 = 6.9, about 6 to 7. One operational change quietly cut the read budget.

Ready: use the stated baseline inputs, then compare each displayed result.

Ada: The chapter’s timing budget decides whether a portal is usable, so let me re-run it and then push the one variable that matters most.

• Dwell time: a forklift at 1.2 m/s crossing a 2 m read zone keeps a pallet in the field for 2 / 1.2 = 1.667 s.
• Inventory chances: at one useful cycle every 120 ms, that is 1.667 / 0.12 = 13.9, about 13 chances to see each tag — enough for a sparse pallet.
• Now double the forklift speed to 2.4 m/s: dwell halves to 2 / 2.4 = 0.833 s, and chances fall to 0.833 / 0.12 = 6.9, about 6 to 7. One operational change quietly cut the read budget nearly in half.

The audit conclusion is that read completeness is not a hardware property but a timing budget, and item speed is its dominant lever — which is exactly why the release record must store the raw read count beside the accepted event (for example 47 and 39 raw observations resolving to 1 crossing), and why a speed change is a hardware-integration retest trigger, not a middleware tweak.

Every number above is taken from the chapter’s own material and re-derived step by step.

Technical boundaries. This RFID audit deliberately does not simulate coupling fields, tag orientation, collision protocols, or reader detuning. It applies the chapter's fixed range, read-rate, power, and integration-budget assumptions.