Hi Don: Yes - it occurred to me after sending the post that I might be able to create the split at the KXPA with a stereo Y-cable/connector. I am using a KXUSB to the computer, with a KXSER cable going from the the antenna controller to the KXPA. It is the KXUSB that presently has no place to connect to.
So - I think I can try a 3.5mm stereo y-junction at the KXPA. Hopefully impedances won't be an issue at 38400 baud... I did look for RS232 multiplexers - they seem to exist for industrial applications. The documentation seemed to be sparse on the web. Anyway - thanks for the pointer :) 73, Steve NU7B > On Jul 8, 2018, at 1:37 PM, Don Wilhelm <donw...@embarqmail.com> wrote: > > Steve, > > Are you using the KXUSB to connect with the KXPA100/KX3, or are you using the > KXSER with a real computer serial port or a USB to serial adapter? > > Since your magloop controller only 'sniffs', it means it should only listen > and never try to transmit on the RS-232 signal lines. If it only listens, > there will be no collisons (RS-232 is not packet oriented, but an > asynchronous communications system). > > If the magloop controller also transmits on the RS-232 bus, you will need > some external device to act as "traffic cop" - note that RS-232 is a point to > point system (unlike Ethernet and others) where there is one driver device > and one receiver at each end. > > So yes, you can use a splitter - one with a 3.5mm stereo plug and two 3.5mm > stereo jacks if using the KXUSB. > If you are using the KXSER cable instead, yes, you can connect a "Y" DB9 > splitter to the DB9 end of the KXSER cable - the computer connects to one > side and the magloop controller connects to the other side of the "Y". > > On 7/8/2018 3:31 PM, Stephen Rector via Elecraft wrote: >> 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? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
