Typically "sniffers" don't have the TX side connected. RS-232 can't have multiple transmitters on either wire.
This is done with SteppIR controller, for similar reasons. SteppIR describes a splitter cable for DE-9 connectors. The same principle (with a much simpler cable, just tip and ring) applies to the 3.5mm connector to the KXPA100. http://www.steppir.com/wp-content/uploads/2011/10/Y-Cable.pdf 73 de Dick, K6KR -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Stephen Rector via Elecraft Sent: Sunday, July 8, 2018 12:31 To: [email protected] Subject: [Elecraft] [KX3] RS232 xcvr control when serial ports are occupied Hy home station is a KX3 + KPXA100, and I can control the radio via the RS232 port on the KXPA. However, recently I added a Ciro Mazzoni magloop to the station, and its controller plugs in to the KXPA serial port to sniff for frequency information, allowing re-tuning on the fly. This leaves no RS232 port left for remote control of the radio. How do I modify this arrangement to add an extra serial port for KX3 control? My first thought is that, since the antenna controller just sniffs for data, I could add a DB-9 Y-cable to provide the extra port at the controller serial port location. However, packets could still collide ...does the protocol handle this? Is there some sort of multiplexer available? Thanks, Steve NU7B ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
