Not wishing to get into an argument but consider Binary-Synch, Uniscope or UTS400 protocols. They are poll and response, RS232c communications systems. Used from mainframe to (dumb) terminal. They are synchronous RS232 of course rather than asynch and so use the clock and other signals ignored by the [IBM PC] cut down implementation of the RS232 connector. RS232 of course only defining the names and voltages on the connector.
From memory a Uniscope (U100) “poll” from the mainframe would be the characters: sync, sync, sync, sync, SOH, RID, SID, DID, STX, text, ETX, BCC. Now that was dug out of the 1970’s if nothing was! Andy, G8TQH > On 11 Feb 2019, at 21:35, Don Wilhelm <[email protected]> wrote: > > Andy, > > "Polling" normally refers to a situation like Ethernet and others where a > response from a particular *addressed* device is requested. > For RS-232, it is "handshaking" (if implemented) telling the DTE when it is > OK to send data - since there is only one transmitter on an RS-232 signalling > line, there is no need for addressing. The transmitting device expects to > communicate to only one receiving device on the other end (although other > receivers can 'listen in'. > > I have worked with RS-232 for over 35 years both professionally (both modems > and DCEs for 20 years) and with ham radio gear and PCs after retirement from > that life. > > If we wish for clear communication, the terms used are important. Ham Radio > "speak" often confuses the proper engineering terms. You hear of ham radio > software that "polls" the radio - in reality, it is simply issuing a command > to the radio and expects a response to that command. That is a > command/response scenerio, and is not really polling. > > Don W3FPR > > On 2/11/2019 3:55 PM, Andy Durbin wrote: >> "I have no idea how your "polling" device works, but with RS-232, thereis no >> polling, " >> >> Point 1 is true. Point 2 is, in my opinion, not true. >> >> A poll is a request for information. The device issuing the poll/request is >> the polling device. For example, sending IF; to a TS-590 is a data >> request, or poll, for the current IF status. The TS-590 responds with the >> full IF word. >> >> Andy, k3wyc >> >> > > ______________________________________________________________ > 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]
