Re: Issues with ACCORD Reference Clock Driver

Hi Jason,
I agree with you to some extent(#1, #2).
I am trying to accomodate the changes in the NMEA driver itself.

Binary format was designed to send GPS time and position data to
another PCI card.
I cannot tell you the whole story but the binary format has GPS
time, sync status and
position. Unfortunately the time message doesnt contain sync
status ! Hence both the
messages need to be checked.

Currently I'm out of station and busy. I shall post the details
of the format very soon.

Accord is the only Indian company manufacturing GPS Clocks. It may
not be as popular
as Garmin or TrueTime in the international market. But we are
using them and they work
fine too.

Venu.


On 12/2/07, Jason Rabel <jason@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
As per your suggestion I would have used the existing NMEA
reference clock driver
for Accord GPS Clock. But there are certain issues as listed below.

1. Accord GPS Clock spits out NMEA at 9600 baudrate
2. It has custom NMEA format for GPS (and the driver is
intended to use this )
3. It also spits out time and status messages in a proprietary
binary format (not yet tested...but wll do )

So instead of changing the clean NMEA driver to support the above,
I still think its better to write and maintain a separate driver.

Comments plz...

#1 above would require changing only 1 line of code from the base NMEA
driver. I've often wondered why you can't pass the baud rate via the conf
file. It makes more sense to me to have the software adjust for the GPS,
rather than having to change the GPS (if possible) to accommodate the
software.

#2 above, depending on the format, could require as little as only 1 or 2
lines of code to be changed / added. At the very worst you might have to
modify the small chunk of code that searches for the time code in the
string, still a very minor modification.

#3 above - Is there any advantage to using the binary format? Is there any
information that NTP can use that would justify the additional code?

I've never heard of Accord until you started posting asking questions about
a driver. Excluding their website, there seems to be no other information on
the Internet about them (or people using them). I wouldn't exactly call it a
'high profile' product.


.

Relevant Pages

  • Re: Issues with ACCORD Reference Clock Driver
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