[time-nuts] Nortel Trimble thunderbolt

[Ed Palmer]

Certainly if you need a full implementation with various control leads 
you might have to dig out the breakout box and figure it out. But the 
volts / no volts idea is still useful for connecting pairs like RTS/CTS 
or DSR/DTR.  But I'm surprised how many devices don't use the control 
leads.  Most of the devices I work with don't even use software flow 
control.

Ed

On 7/5/2013 10:06 PM, Chris Albertson wrote:
> On Fri, Jul 5, 2013 at 7:03 PM, Ed Palmer <ed_palmer at sasktel.net> wrote:
>
>> I always cursed when I tried to figure out how to wire an RS232 cable
>> until I realized that transmit had a voltage on it while receive was close
>> to zero volts.  So now I just remember that volts on one end connects to no
>> volts on the other end.  Works every time and I don't have to think about
>> straight or cross-over.
>
> That only works if there are only three wiresand no handshaking.  What if
> there is DTE/DCE and so on?
>
> But I think in this case it is just a three wire connection but still there
> is room for errors like for example is one of them a TTL level and the
> other RS-232.  Some times you can mix the two, sometimes not.
>