How is unintended operation prevented on a wireless remote control?
Prevention of unintended operation is one of the headings IEC/EN 62745 addresses explicitly. Four layers are used in practice: pairing each transmitter-receiver pair with a unique identity code, serial data integrity and error detection, the command not passing automatically when the device is switched on, and two-handed or enabling-button operation for critical motions.
"Unintended operation" comes from two different sources: human error and signal error. Each requires separate measures.
On the signal side:
- Each transmitter-receiver pair is paired with a unique identity/address code. The transmission of another remote on the same site is not processed because the code does not match.
- Serial data integrity and error detection prevent a corrupted packet from being taken for a valid command.
- The establishment and loss of communication are monitored; if there is no valid signal the motion is released.
On the operating side:
- When you energise the remote, a button that has stayed pressed is expected not to pass as a command.
- Arrange a way of carrying the remote such that the buttons are not subjected to pressure when it is attached to a belt or strap; putting it in a pocket is the most frequently overlooked risk.
- At the end of the shift, switch the remote off and store it in a locked cabinet; prevention of unauthorised use is a heading of the same standard.
- Do not trigger critical motions outside the operator's field of view.
These items are the general approach of the standard. Confirm from the user manual which mechanisms a particular set implements, and also provide a hard-wired emergency stop on the machine.
Full article: Wireless remote control installation: pairing, relays, safety