Are VEX IQ robots allowed to be tethered during match play? We were at a tournament where this was allowed and the referee (head included) were unsure.
No, according to the manual all robots should have a smart radio and have to be wireless paired to the robot.
b. Robots must use one (1) VEX IQ 900 MHz radio, VEX IQ 2.4 GHz radio, or VEX IQ Smart Radio in
conjunction with their VEX IQ Robot Brain.
(not an IQ competitor, but I’m interested to learn more about the game and might head ref some events at some point)
If by “tethered” you mean directly wired to the IQ brain, this would probably be illegal.
First of all, as Sharky_do has already stated, R9b states that robots must use some sort of Radio. The inspection checklist (https://www.roboticseducation.org/documents/2019/09/viqc-robot-inspection-checklist.pdf/) requires inspectors to verify that the “Robot installed VEX IQ Brain can communicate with the VEX IQ Controller and is properly paired using VEX IQ 900 MHz radio, VEX IQ 2.4 GHz radio, or VEX IQ Smart Radio.”
I’d say the wire could also possibly cause an “unnecessary risk of entanglement” as quoted from rule R14, so that would be another thing to watch out for.
Hope this clears things up.