Does the movement stop if the remote control goes out of range?

Yes: with no valid signal the receiver releases its relay outputs and movement stops. The transition is not sharp; near the limit the response first stutters.

Yes. When the receiver does not receive a valid signal it releases its relay outputs and the movement stops; this is not a fault but the desired behaviour. The transition does not happen at a sharp boundary, though: as you approach the range limit the response first becomes intermittent, then breaks off completely. In this intermediate zone the operator gets the feeling that “the remote control is sticking”.

Why the range limit is not sharp

Going out of range produces the same result as a flat battery: the transmission does not reach the receiver, the receiver cannot see a valid command and releases its outputs. As the signal level falls there is first the odd lost packet, then a visible delay, and finally a complete break. This intermediate zone is not a fixed distance either; the stance of the operator, the direction of the antenna, a load standing in between and the weather change it a little on each pass. Recognising the signs of a falling range lets you notice early that you have reached the limit: a command being swallowed once, then a delay, then a break.

Whose word is the declared figure? The manufacturer measures and declares the range under defined conditions; the condition on site, however, is set by the installation. That is, the manufacturer gives the number and you verify that it holds. In installations that skip this distinction the argument always knots at the same point: the device conforms to its declaration, the site does not conform to the condition in the declaration.

Under what condition does the declared range hold

The values stated for AXI sets are for open field; concrete walls, steel construction, stacked containers, and interference from inverters and welding machines lower this value markedly.

Line-of-sight range is an upper bound, not a working radius. Planning done without taking the effect of concrete and steel structures into account comes back at you on site; in an enclosed workshop do not rely on the whole figure.

How you determine the working radius

1. Finish the installation, fit the antenna in its permanent place and run the machine with its normal load.
2. Give commands from the points where the operator actually stands; measure on a full site, not an empty one.
3. Mark the distance at which the intermittent response starts — the range margin is calculated back from that point.
4. Repeat the test while the inverter and the welding machine are running; the result usually changes.
5. Make the measurement separately with the battery full and with it half used; the two do not come out the same.

As a rule of thumb keep the actual working radius markedly below the declared open field range; determine the real limit with a site test after installation.

Where stopping is not enough

The movement stopping at the range limit is the desired result when the operator has moved too far away to see the machine; but on its own it does not provide safety. The movement stops, the load does not come down: on an electric crane the load stays hanging on the brake. With an inertial load the movement carries on a little further after the output is released. And there is a visibility problem — even if the range is adequate, if the operator cannot see the load they should not be operating. That is why the range behaviour does not remove the need for a wired emergency stop on site.

After installation, measure the distance at which the intermittent response starts, mark it on the ground and show it to the operator. If the range shortens over time the cause is usually the antenna, a connector or the battery; look at the reasons why the range comes out lower than the catalogue value. Confirm the loss-of-range behaviour of your set from the user manual.

The full topic: 433 MHz or 2.4 GHz?

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