| Farshad Mohajeri 06/11/09 12:11 Read: 297 times |
#166020 - RS485 Converter Responding to: Joseph Hebert's previous message |
Hi Joseph,
My device takes data from USB port and converts it to RS485. The RS485 side is optically isolated from USB side. And yes, it has a connector for RS485 line and I connect a short RS485 cable while testing the communication. The device was initially designed as self-powered. After lots of tests I converted the design to bus-powered. Changing from self-powered to bus-powered hasn't improved its EMI performance, at least I couldn't see a noticeable change. The only thing that made a serious improvement in EMI performance was using a shielded USB cable instead of a shield-less one. (The funny thing is that I was thinking that I'm using a shielded cable from very beginning, until I actually measured it!) A picture of my device can be found here: http://www.8052.com/forum/read/165885 |
| Topic | Author | Date |
| FT232R USB to Serial | Farshad Mohajeri | 06/04/09 12:30 |
| Something silly ? | Steve M. Taylor | 06/04/09 13:36 |
| Capacitive Coupling | Farshad Mohajeri | 06/04/09 15:13 |
| Ideas | Steve M. Taylor | 06/04/09 15:51 |
| there is always SOME coupling... | Jan Waclawek | 06/04/09 15:52 |
| crash and reset the USB connection | Andy Neil | 06/04/09 16:24 |
| Very unlikely | Farshad Mohajeri | 06/04/09 16:30 |
| PC USB crash | Oliver Sedlacek | 06/05/09 03:06 |
| Isolated hub? | Andy Neil | 06/05/09 03:18 |
| PC Isolation? | Andy Neil | 06/05/09 03:20 |
| just blame the chip. | Erik Malund | 06/04/09 20:29 |
| Please see my other post with image (nt) | Farshad Mohajeri | 06/05/09 13:25 |
| is connector grounded on Your side? | Stefan KAnev | 06/05/09 01:42 |
| Huh? | Joseph Hebert | 06/05/09 09:21 |
| yes | Stefan KAnev | 06/05/09 09:38 |
| Floating the end of the cable shielding | Joseph Hebert | 06/11/09 11:37 |
| Was using wrong cable | Farshad Mohajeri | 06/11/09 12:36 |
| More information | Farshad Mohajeri | 06/05/09 13:21 |
| Hmm | Steve M. Taylor | 06/05/09 16:18 |
| isolation | Jan Waclawek | 06/06/09 04:29 |
| Update... | Farshad Mohajeri | 06/11/09 03:40 |
| USB and RS485 | Joseph Hebert | 06/11/09 11:44 |
| could this be it | Erik Malund | 06/11/09 12:01 |
| Tested both self-powered and bus-powered | Farshad Mohajeri | 06/11/09 12:41 |
| RS485 Converter | Farshad Mohajeri | 06/11/09 12:11 |
| el.circui? | Stefan KAnev | 06/11/09 13:59 |
| re: why? | Andy Peters | 06/19/09 12:22 |
| USB 1.1 | Farshad Mohajeri | 06/19/09 15:20 |
| re: USB 1.1 | Andy Peters | 06/19/09 16:34 |
popular culture | Jan Waclawek | 06/19/09 17:10 |