V25 pinout?

[Tony Duell]

> 
> On Fri, 26 Aug 2005, Tony Duell wrote:
> 
> > Does anyone know the pinout of the V25 interface (DB25 connector)? No,
> > this is not a typo for V24, which I know ot be much the same as RS232.
> > V25 seems ot be an interfce for autodiallers.
> 
> I just looked, and V.25 explicitly refers to the V.24 pinout. V.25 (and 
> V.25bis and V.25ter) only specify procedures user over the v.24 circuit in 
> automatic dialling scenarios (when to raise/lower which signals and a 
> DTE-DCE command/response format) V.25ter is the familiar AT command set.

Hmmm....


I have an instrument here (an HPIB extender) with 2 DB25's on the back. 
One is marked 'RS232 V24' and is clearly a normal-ish serial port to 
connect to a modem. The other is for an autodialer and is marked 'RS336 
V25' (I think that's the right RS number, maybe RS339). I don't think 
that's a normal serial port, but it does seem to use the same voltage 
levels (in there there are what look like 1488 and 1489 chips linked to it).

-tony