| ??? 10/23/07 13:37 Read: times |
#146074 - no, it is not Responding to: ???'s previous message |
"ground problem isnt a problem "
Yaa thats true no, it is not NOTHING can make "ground problem isnt a problem" proper means can reduce the problem to tolerable levels. Especially between two separated units a ground wire is about as shitty as can be. Just try once to put a scope in differential mode between 'gnd' and'gnd'. I Think it was Steve that once posted that the ground to ground wire melted the insulation in one case. One somewhat imperfect solution is to connect only one of the units gnd to 'earth' (power 'ground') and connect gnd to gnd. The two solutions that work the best is optical isolation and differential signalling. I am a fan of differential signalling I use 485 transcievers for control signals as well as serial data. For your particular project I would use RS422 instead of RS232. Erik |
| Topic | Author | Date |
| UART Maximum | 01/01/70 00:00 | |
| Baud rate ? | 01/01/70 00:00 | |
| Baud | 01/01/70 00:00 | |
| RS232? | 01/01/70 00:00 | |
| 100m on 4800 BPS | 01/01/70 00:00 | |
| How? | 01/01/70 00:00 | |
| true RS232 | 01/01/70 00:00 | |
| you do not say how | 01/01/70 00:00 | |
| a) ----- option only | 01/01/70 00:00 | |
| Twisted Pair | 01/01/70 00:00 | |
| He would not be THAT ignorant, I hope | 01/01/70 00:00 | |
| a much better idea | 01/01/70 00:00 | |
| Assumption | 01/01/70 00:00 | |
| a much better idea | 01/01/70 00:00 | |
| WRONG | 01/01/70 00:00 | |
| panacea ---> The Godess of all cure :) | 01/01/70 00:00 | |
| of course, you need to connect gnd | 01/01/70 00:00 | |
| ground problem isnt a problem | 01/01/70 00:00 | |
| Call a spade a spade... | 01/01/70 00:00 | |
| no, it is not | 01/01/70 00:00 | |
| Differential | 01/01/70 00:00 | |
| no, it is not | 01/01/70 00:00 | |
| Oh yes it is! | 01/01/70 00:00 | |
| since you control both ends ... | 01/01/70 00:00 | |
| Minimum RS422/485 | 01/01/70 00:00 | |
| mimum length for 485/422 | 01/01/70 00:00 | |
Thanks for the input to all | 01/01/70 00:00 |