On Mon, Jan 9, 2012 at 10:43 AM, Chuck Swiger <[email protected]> wrote:
> On Jan 8, 2012, at 11:45 PM, David J Taylor wrote: > > Chris, it also occurs to me to enquire exactly how the RS-232 data is > being carried over the cat-5 cable. What is the wiring? > > Searching for "RS232 over RJ45" suggests the standard pinout is known as > EIA/TIA 561. > Basically, it closely resembles the EIA/TIA 574 (DB9) wiring, but DSR and > RI have been combined. > That is what I did. You can buy a DB9 shell that has an RJ45 on the back. When you buy them the DB9 pins are loose and you can push any pin in any hole but I Followed the "standard" not that it really matters if both ends are the same. The problem was simply the length of the wire and that it goes through an RJ45 patch panel and two in-wall keystone connectors. It works fine with a 4 foot length of cat-5 patch cord but but with the longer run. I tested using only the short patch cable. Then with the longer run I seem to "loose" about 2% of the pulses. It's odd that it is only about 2%. Likely something simple like a 100R resister would fix it. Solution: Don't do RS-232 over cat-5. Move the computer. Use a two foot serial cable and then the same cat-5 cable for a network connection. Moving the computer will place it close enough that I can connect it to other sources of time. I have a a Trimble "Thunderbolt" GPS that could be used and also a rubidium oscillator. Chris Albertson Redondo Beach, California _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
