Note however that the M12+T’s I/Os are 3V, not 3.3V and not 5V. On Jun 11, 2014, at 19:46 , paul swed <[email protected]> wrote:
> Chris is correct many GPS receivers do not output anything till queried. > Further it seems the TX and RX data may need to be swapped. That has bagged > me a few times because it depends on the perspective. Easier to just try > swapping them. > The max series does indeed perform the the logic translation a +5 signal > ttl/cmos to -12V rs232. > Regards > Paul > WB8TSL > > > On Wed, Jun 11, 2014 at 1:50 PM, Chris Albertson <[email protected]> > wrote: > >> First off if you are getting PPS on the PPS pin the GPS is working. By >> default I don't think the MT12 outputs any serial data unless in response >> to a query. By default it is not a NEMA device. >> >> The protocol is binary so it would be rely hard to control it with a Window >> terminal program >> >> The simplest way to use the MT12 is to connect it to an NTP server. You >> may not want to run NTP, you want a GPSDO but NTP knows how to get the MT12 >> running and NTP has a good log file that you can read to track what the GPS >> is doing. There are other software for controlling MT12 and other Oncore >> series GPSes that are better but NTP is already installed on many computers >> >> The other thing to watch with serial RS232 is the polarity. I'm pretty >> sure the MAX chip acts as an inverter. That might be good because RS232 >> uses negative logic with a low voltage being a "one" and a higher voltage >> being a "zero" Well at least on the data pins, the control, I think is >> positive logic. If you get the polarity wrong it does not work >> >> >> >> On Wed, Jun 11, 2014 at 9:04 AM, Stephen <[email protected]> wrote: >> >>> Hello everyone, >>> >>> After reading quite a bit from your archives i've decided to try a put >>> together a 10MHz reference. >>> >>> I've picked up a oncore M12+T GPS card and have tried to initialise it >> but >>> without any success thus far. >>> >>> The user manual for the M12+T seems to suggest that i should be able to >>> hook the txd and rxd pins to a MAX3232 and be able to use the Winoncore >>> software to configure the card. >>> >>> At power up the M12+T pins 1 & 2 are at 3V. After 10 seconds pin 2 sinks >>> to 0V, pin 1 idles at 3V and pin 4 give 1PPS. No serial output from the >>> card at all. >>> >>> Anyone have experience of connecting an M12+T to rs232? >>> >>> Stephen >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> >> -- >> >> Chris Albertson >> Redondo Beach, California >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
