[RC232] I would like to know how to use the pins N°27 and 28 on the RC2500HP Pin 27 and 28 must be left open. Last Update: August 8, 2017 December 20, 2016 1633 RC232 Q&A Related Knowledge Base Posts -[RC232] For a new project I would like to obtain an ultra long range, better than the RC1780HP[RC232] I get no more prompt when asserting/deasserting Config line. I use the M command in order to modify different settings.[RC232] Are the Settings made during Configuration persistent, or do these settings need to be made each time the device is powered on ?