Back in Dec 2013, Chris North wrote: >I have managed to fix it, and it was a bit unexpected. When I first >installed the Sure, I used a USB connection and got it working OK. I then >used a Serial-USB adapter and was pleased to find that it passed DCD and >that PPS was working. The jitter was rather high, though - about 0.3 mS. I >bought a 2-port serial PCI card and a serial cable, and immediately had a >massive improvement in performance. Recently, however, I found that PPS had
>stopped working, as you have seen above. > >What I think happened was this: when I plugged in the new card it used the >standard Windows serial.sys, which I replaced with serialpps.sys. Now this >card is part of a range of multifunction cards that offer various I/O >interfaces. At some time Windows Update probably found the manufacturer's >drivers and installed them (automatically, or as an option that I just >accepted). The new driver ignores serial.sys and has its own software. So I >poked around in the registry and changed the ImagePath for one of the card's >new services to point to serialpps.sys. This seems to have fixed it. As I >don't use the COMn ports for anything else, I won't worry about possible >side-effects. I am trying to get PPS working with a Sure GPS board connected to a laptop running Win7. I'm not getting very far and I'm guessing it's because neither of the interface options available to me use the serial.sys driver: - Direct connection of the Sure's USB port to the laptop means using the Silicon Labs 2102 chip on the Sure board and it uses drivers called silabenm.sys and silabser.sys - Connecting the Sure board's RS-232 output to the laptop via a Prolific USB to serial adaptor means using the Prolific driver ser2pl.sys Chris, if you still follow this listserv, could you tell me which serial-to-USB adaptor you were using which successfully passed PPS to ntp? I am not expecting the jitter to be any better than of the order of 1ms since the USB interface samples the DCD line at 1024Hz but would still like to try to get my setup working. Thanks, Richard Steedman. _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
