On Friday 01 January 2016 06:23:06 andy pugh wrote: > My lathe build is going to have a smart-serial device mounted in the > lathe apron. This means that I need a CAT5 cable in the drag-chain, > and also a 24V supply for the proximity sensors. > Finding oil/coolant resistant CAT5 rated for drag-chain use is likely > to be a challenge. > I have lots of this cable: > https://picasaweb.google.com/108164504656404380542/Holbrook#6217838146 >609796818 (Lapp Ölflex drag-chain encoder cable). > Is there any reason to think that the 2x3 screened pairs in that cable > will be unsuitable for transporting smart-serial data (if I can > persuade an RJ45 connector on to them)?
Other than cat-5 is 4 twisted pairs with no shielding, no. If its a real ethernet, the shielding would mess up the termination impedance. Even going thru a pair of crimp on rj45's plugged into a splicer block is enough of an impedance and echo causing bump that a 100megabit circuit can downgrade itself to a 10megabit circuit. We've been bitten by that when rearranging gear in the racks at the tv station & had to add another 4 feet of cable. To get the speed back Jim had to pull new cable. For serial, where signalling is single ended, I'd make sure that txdata and rxdata were in separate shielded pairs. I'd assume the protocol is similar to the common 7 wire that is usually terminated in db9 connectors? That works well for the baud rates used 20 years ago, but no first-hand experience above 56kbaud, and I expect this is 10x that. 460k or better. At those speeds termination is very important to control edge reflections and ringing. Any idea what the baud rate is, Andy? These are tires I've never kicked. :( Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
