27 Aug
2005
27 Aug
'05
12:34 a.m.
On Fri, 26 Aug 2005, Tony Duell wrote:
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
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.