103 Plex Knock Monitor

I was reading through the instructions for my new plex knock monitor and under the diagrams of trigger connections they have the trigger "wired" into the negative signal from the ecu for the ignition coil (option c) but then tell you to select rising edge for this. i could have sworn you would need to select falling edge for this as Andre had it set to that for the brz, which i am certain is negative signal for the ignition coil. Is this a typo? or am i mistaken?

thanks