| ??? 09/13/06 14:55 Read: times |
#124204 - stick to the National and B&B stuff Responding to: ???'s previous message |
Ironically, the more you download, the more confusing it gets...
What you find on the net on RS-485 is as bad as what you find on many other subjects, every idiot that think he has understood something seems to immediately publish his 'wisdom'. There are entries "how to do RS485 without termination resistors" and similar male cow manure all over the net, I even have seen "wiring RS485 in a star configuration" OUCH!!. A typical idiocy (this from the wikipedia) "Ideally, the two ends of the cable will have a termination resistor" HOGWASH, there is no 'ideally' here. I have, in the past, advised some manufacturers to no avail of blatant errors in their appnotes, even that is not a safe place. I have, however - on the subject of RS485 - found the appnotes from Nationak semi and B&B to be "accrate enough". The Maxim notes are full of 'oversights'. Stick to the National and B&B stuff, discard the rest and you will not be (too) confused. Erik PS I'll save Charles from pointing out that I have occasionally been the "idiot that think he has understood something", but the advantage of publishing in a forum format is that you get corrected in the same place, thus no confusion. The isolated post on the net has no such correction feature. |
| Topic | Author | Date |
| RS485 and DE, \RE | 01/01/70 00:00 | |
| not pantyhose | 01/01/70 00:00 | |
| Thanks Erik | 01/01/70 00:00 | |
| stick to the National and B&B stuff | 01/01/70 00:00 | |
| the worse 485 wiring | 01/01/70 00:00 | |
| automatic termination is the solution | 01/01/70 00:00 | |
| what\'s that? | 01/01/70 00:00 | |
| its simple | 01/01/70 00:00 | |
| Cool! | 01/01/70 00:00 | |
| hmmm | 01/01/70 00:00 | |
| actually very simple | 01/01/70 00:00 | |
| I am still none the wiser | 01/01/70 00:00 | |
| chain | 01/01/70 00:00 | |
| I've got it. | 01/01/70 00:00 | |
| It works, you work out the details | 01/01/70 00:00 | |
| maybe not biasing A&B... | 01/01/70 00:00 | |
| then use a high enough voltage | 01/01/70 00:00 | |
| biassing | 01/01/70 00:00 | |
answers | 01/01/70 00:00 | |
| if you supply via cable... | 01/01/70 00:00 | |
| Transceiver with switchable termination | 01/01/70 00:00 | |
| thanks for the tip! | 01/01/70 00:00 | |
| great.Oliver, just this | 01/01/70 00:00 | |
| it would, but think this through | 01/01/70 00:00 |