Jamming
Jamming is filling a band with continuous transmission so that the receiver can no longer capture a valid packet. It may be deliberate, but a faulty device stuck in transmission or a strong noise source produces the same result. In a properly designed system the outcome is not loss of control but a safe stop.
From the receiver's point of view there is little practical difference between jamming and heavy interference: in both cases no valid packet arrives. What the system does then shows the quality of the design.
- Correct behaviour: if no valid packet is received for a defined period, the outputs go to the safe position and the condition is signalled to the operator.
- Wrong behaviour: maintaining the last command. That means motion continuing without supervision.
- Resilience: frequency hopping protocols are less affected by a narrowband jammer; against a strong wideband source, however, no modulation is fully immune.
The form most often met in the field is not deliberate: a faulty radio, a transmitter stuck in trigger, or a defective switching supply. An effective diagnostic method is to carry the remote control and the receiver to different points on the site and see whether the link comes back. On the AXI side, the HCT402's 250 ms timeout is the answer to this scenario.
Context where this term is used: Wireless remote control installation: pairing, relay, safety