[ntp:questions] Very large jitter and offsets on GPS ref clock after upgrade to "p5"

E-Mail Sent to this address will be added to the BlackLists Null at BlackList.Anitech-Systems.invalid
Sat Jan 7 02:29:35 UTC 2012


On 1/6/2012 3:18 PM, Mike S wrote:
> On 1/6/2012 4:54 PM, E-Mail Sent to this address will be added to the
> BlackLists wrote:
>> On 1/6/2012 12:28 PM, unruh wrote:
>>> Eg, your encore pluse is a TTL level pulse (0-3 volt transition)
>>
>> I thought he indicated he had a Oncore UT+ ?
>>
>>   The M12M Oncore specs TTL interface (0 to 3 V)
>>   The UT Plus Oncore TTL specs TTL interface (0 to 5 V)
>>   The GT Plus Oncore specs TTL interface (0 to 5 V)
>
> No, TTL (the original 54/7400 series) has a 5V _Vcc_. The output logic
> levels are typically 0.2 and 3.4 V. Rounded, a 0-3 V transition.

What do you mean No?  No to the EIA/TIA specs for RS232? (which you trimmed)
 No to the specifications in the datasheets for the products?

 I you don't like Motorola's / iLotus's / SiRF's / CSR's published specifications,
   or the wording they used, you'll have to take it up with them.
  However as those products are discontinued,
   I doubt they'll care about anyone's opinion of their wording in those specifications.
    The text the M12M datasheet(s) use is: Serial Communication "TTL interface (0 to 3 V)"

More clues farther down in the Datasheets:
<BlockQuote>
THE M12M SERIAL PORTS ARE NOT 5V LOGIC COMPLIANT
For input signals, minimum input high voltage is 2V
 and the maximum input high voltage is 3V.
Minimum input low voltage is 0 V
 and the maximum input low voltage is 0.8 V.
For output signals, minimum output high voltage is 2.4 V
 and the maximum output low voltage is 0.5 V.
This interface is not a conventional RS-232 interface
 that can be connected directly to a PC serial port,
 an RS-232 driver/receiver is required to make this connection.
</BlockQuote>


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