The OM2500A has 2 serial ports. It is designed to be patched inline between a computer and the K3.
73, Josh W6XU Sent from my mobile device > On Dec 14, 2015, at 5:11 AM, Don Wilhelm <[email protected]> wrote: > > Charles, > > I don't know the specifics of your OM2500A amplifier, but I do know about > RS-232. > First, RS-232 is a point to point system. The use of "Y" connectors is not > the norm and are applicable only under certain specific conditions. > Those conditions are that the device added by the "Y" connection has no > active drivers on the RS-232 signals - only line receivers are permitted. > > Think of it this way - a driver on an RS-232 line can have a negative voltage > of up to -25 volts, and a positive voltage of up to +25 volts. > Imagine that one driver is trying to produce -25 volts while the other driver > is trying to produce +25 volts. In other words, they 'fight' with one > another, and the result is 'confusion' because the receiver listening on that > RS-232 signal line will not respond to a voltage that is less than 3 volts > positive. > > In other words, use a "Y" connector only when the added device is capable of > being put into a "listen only" mode (with its drivers disabled). > Look at your amplifier information carefully to see if it can be placed in a > "listen only" mode. If not, you cannot use it with a "Y" connector. > > The SteppIR is one example of a device that can be placed in listen only > mode, so the use of a "Y" connector is possible, but that is not the general > case. > > Bottom line, you can connect only *one* RS-232 device to another in the > general case. Introducing a 3rd RS-232 device (with a "Y" connector) > requires special conditions be present in that 3rd device - it must only > listen to the data traffic and not attempt to transmit data. > > 73, > Don W3FPR ______________________________________________________________ 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]
