AverageValueCheck

AverageValueCheck measures the true average of a signal over a fixed duration, on demand, and compares that average against four levels.

Use it for a bounded test rather than continuous supervision: sample a pressure for two seconds after a valve closes, or a torque after a move settles, and decide whether the result is acceptable.

flowchart LR
    i1(["input"]) --> B["AverageValueCheck"]
    i2(["activate"]) --> B
    p1(["duration"]) --> B
    p2(["tooLow, low, high, tooHigh"]) --> B
    B --> o1(["average"])
    B --> o2(["sum"])
    B --> o3(["counter"])
    B --> o4(["busy"])
    B --> o5(["isTooLow, isLow, isHigh, isTooHigh"])

The average is exact, not filtered — every sample over the window carries equal weight. sum and counter are published so you can check the arithmetic yourself.

All four levels default to 0. Until you set them, isHigh and isTooHigh are true for any positive average. Set all four before reading any flag.

The result persists after the measurement ends, which is what makes the block useful — but the flags are also computed before any measurement has run, from an average of zero. Read counter alongside them: a counter of 0 means no measurement has happened.

Signals

Inputs

Outputs

Parameters

All are persistent and survive a controller restart. Nothing checks that the four levels are in order. No parameters exist below this block.

The bands are nested: with the intended ordering, an error also raises its warning. For “warning but not error”, test isLow and not isTooLow.

Setup

1. Connect the signal you want to measure to input.
2. Set duration to how long you want to sample for.
3. Set all four levels. They default to 0, and until you set them the flags are meaningless.
4. Bring the machine to the state you want to measure.
5. Raise activate from false to true and confirm busy goes true.
6. Lower activate again. The block will not clear it for you, and a second measurement needs a fresh rising edge.
7. Wait for busy to fall, then read average and counter. Confirm counter matches the duration divided by your task period.

This block only measures and compares. It does not move anything and cannot be made to.

Tuning

1. Set duration from the physics, not from convenience. It must be long enough to average out the noise and short enough that the quantity has not changed by the end.
2. Trigger a measurement with the machine in a known-good state and record the average. Repeat it a few times to see the spread between runs.
3. Set the error levels outside that spread, with margin.
4. Set the warning levels inside them, where you want to be told early.
5. Trigger with the machine in a known-bad state and confirm the right flags come up.
6. If the spread between runs is too wide to place levels, lengthen duration — the spread falls roughly with the square root of the sample count.
7. Watch average while a measurement runs to see how quickly it settles. If it is still moving at the end, duration is too short.
8. duration is in seconds, so a task-rate change does not move it — but counter will change, because the sample count depends on the rate.

The average is readable while the measurement runs. Only the value once busy falls is the result.

A starting point for a settled-torque check:

duration = 2.0
tooLow   = -5.0
low      = -2.0
high     =  2.0
tooHigh  =  5.0

Limits and errors

This block logs nothing, ever. Every condition above shows as a value on a trace, or not at all.

Verified against motorcortex-control3 3.30.0 (bc348fd).