geek On Thu, May 21, 2020 at 1:28 PM Chuck Macenski <ch...@macenski.com> wrote:
> Isn't history fun. As found on the Internet: > > DTE vs. DCE > > This is one of the most misunderstood areas of RS-232. DTE stands for Data > Terminal Equipment, and DCE stands for Data Communications Equipment. DTE > is typically either a dumb terminal or the serial port on a > computer/workstation. DCE is typically a modem, DSU/CSU, or other piece of > data communications equipment, hence the names. This is all most people > really need to know about these terms. Where it gets confusing is when you > start to talk about signal definitions and direction. > > For example, it's easy for someone to understand that when you transmit > data, you send it out. However, when you talk in terms of DCE, it becomes > an input signal. This is because the specification was written from the > perspective of the DTE end of the link. Another example is the Receive Data > signal is an input to DTE, but an output from DCE. Therefore, a straight > through "one to one" cable is all that is necessary between a modem and a > standard DTE serial port. However, if you want to connect two DTE ports > together, you have to simulate the existence of the pair of DCE devices, > typically modems that would normally be between the two DTE devices. This > is where the null-modem device or cable comes in. > > On Thu, May 21, 2020 at 12:48 PM Adam Moffett <dmmoff...@gmail.com> wrote: > >> Sometimes when a port is labeled "Tx" they mean "this port transmits". >> >> Sometimes when a port is labeled "Tx" they mean "connect the transmit >> from your other device here". >> >> So sometimes you have equipment wanting cabling from Tx to Tx, and other >> times you want Tx to Rx. Is there some standard or rule of thumb for >> when it's done one way or the other? Or is it just a toss up? >> >> >> -Adam >> >> >> >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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