A cloning or sequencing chip is read in exact channel batches. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Read channels batch addresses
The chip has 20 addresses and 4 active readout channels, so one repeat needs 5 passes.
Npasses=420=5
Repeat reads multiply scheduled passes
With 3 repeat reads per address, the schedule has 15 passes. Clone identity and base calling are outside this count.