Hi, I'd already admitted my miss on that one in an earlier reply (don't know how i missed it but it was not a controlled copy of the spec ;-) . That not withstanding, show me a readily available receiver chip that actually meets that requirement. Most equipment that I've seen that would not work with 5V logic levels was failing to respond to the positive input level not the lack of a negative level. Ofteh this appeared to be caused by external circuitry, most likely intended for EMI/ESD/surge protection.
________________________________ From: Mike S <[email protected]> To: [email protected] Sent: Tuesday, 28 January 2014, 2:01 Subject: Re: [time-nuts] Trimble Thunderbolt 1pps On 1/27/2014 1:33 PM, Robert Atkinson wrote: > I looked at this a while ago. The "spec" only defines transmission levels, it > does NOT specify receive thresholds. It certainly does... "2.1.3 For data interchange circuits, the signal shall be considered in the marking condition when the voltage on the interchange circuit, measured at the interface point, is more negative than -3 volts with respect to Circuit AB (Signal Common). The signal shall be considered in the spacing condition when the voltage is more positive than +3 volts with respect to Circuit AB (see 6.2). The region between +- 3 volts is defined as the transition region. The signal state is undefined when the voltage is in this transition region." - ANSI TIA/EIA-232-F (1997) _______________________________________________ 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.
