The dashed step line is the basal profile: the hourly rates programmed in the pump. The filled steps are the basal actually delivered. Where the fill rises above the dashed line, the loop raised the rate with a temporary basal; where it drops below it or to zero, delivery was reduced or suspended.
The COB line is the loop’s estimate of absorbable carbohydrate still active in the body. It is reported with each device-status update, so breaks in the line indicate missing loop-status data rather than zero carbs.
Boluses (triangles, units) and carbs (circles, grams) sit on the same time axis as the readings, with a guide line down into the glucose lane. Glucose is green inside the 3.9–10 mmol/L target band, red above it and blue below it.