Serial line switch

  • Thread starter Chrisstoffer, Herman
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Chrisstoffer, Herman

Hello list, I am looking for a serial line switching device which routes a single serial line either to output a or output b. - this device should be remote controllable. Say issue a switch command from a remote location via a serial link via some kind of protocol. - it should be possible to cascade a great number of lines and still be able to control them from a remote location. Kind Regards Herman Chrisstoffer Project Engineer Yokogawa ISS bv * +31 55 5389584 * +31 55 5389510 * mailto:[email protected]
Go to and take a look at their Multiport Device Servers. They accept a single Ethernet connection from a PC or other device and provide several serial ports. Each serial port on the Lantronix device has it's own IP address and port number. You can connect to and control any port from anywhere on your ethernet network.

kalpak dabir

assuming you require a serial mux, I did it a few times for rs232 by simply converting the signals to ttl and controlling(see below) 3 state switches in between and then converting back to rs232, now a days rs232 chips with enable control are available which will simplify the design further. In fact if only a few lines are to be controlled and you have not used rts or dtr of the serial port then they can be used as control lines. for rs485 the chips have all control logic built in anyway.

Robert Dusza

Herman, Try the two position switch from Blackbox, M/N SW980A. We will be using it via I/O to switch the serial line for programming in and out. Hope this helps. Bob Robert J. Dusza, Jr. Treatment Manager (V) 1-860-647-3219 (F) 1-860-647-3150 E-mail - [email protected] Manchester Water & Sewer Dept. 125 Spring St. P.O. Box 191 Manchester, CT 06045-0191

Curt Wuollet

Hi Try Black Box for this item. I used something like this a few years ago to dial into a site and switch to one of several machines. I had about a dozen UNIX machines there and I could pick one with a keystroke sequence. All I remember is that I got it from them. Modem bank manufacturers would have a line on this too as they need to individually select them. Regards cww
I have used a device like the one you describe. It was purchased from Black Box. It is called a Code Operated Switch, and the one I used had one input and eight outputs. You can contact black box at
You can accomplish this using a code-operated switch, such as those available from Black Box. See their Web site at They use specific text sequences to cross-connect different ports. Several versions are available, including ones with hardware switching functionality in addition to code-operated switching.