[time-nuts] Trimble Thunderbolt Rs-232 Levels

[Björn Gabrielsson]

On Tue, 2008-02-12 at 21:48 -0800, Darrell Robinson wrote:
> Thanks for the quick reply.  It does have the 9 pin connector (DB-9?).
> 
> The main source of my uncertainty comes from the "ThunderBolt GPS Disciplined Clock Manual ver. 3.0" on page 3-18.  In table 3-3 where it shows the pinouts, the protocol mentions TTL.
> 
> Here is what my module looks like -
> 
> 
> 
> I think I will apply power to the module and measure the levels from the port.  If it is TTL out, I will need to do a level shift anyway to give the computer proper voltages to run it's serial port.
> 
> Darrell
> 

Level converter arrangements are good to have handy!  Note, however that
many PC serial ports will accept a "raw" TTL PPS signal, even though the
ca 0V low level formally violates the RS232 spec. Also, if you are using
a laptop, do measure the output levels from its serial port - its not
unheard of - that they have almost TTL- levels.

--

    Björn