| ??? 08/18/06 12:19 Read: times |
#122549 - once again Responding to: ???'s previous message |
WHY THE HECK can nobody learn to preface 'true when low' signals with a 'marker' I use !RE, but do not care if you use _RE ~RE or whatever BUT, DARN IT, USE A MARKER.
Just look at the confusion in the two previous posts coming from this fact. So, tie DE and !RE together, after a transmission wait a bit time and then pull it low to receive, after receiving wait a bit time and then pull it high to transmit. The bit time wait is required because the interrupt comes in the middle of the stop bit for receive and at the beginning of the stop bit for transmit (I may have the explanation a bit wrong, but the waits are required). Are you sure that My other device is running for RS485 connection is not RS-422 (two pairs) or the incorrectly named "two pair RS-485" if that is the case, all that has been posted so far by others and me is WRONG. Before going on is this two pair communication or one pair communication???? Erik |
| Topic | Author | Date |
| 485 connection with 8051 | 01/01/70 00:00 | |
| Why? | 01/01/70 00:00 | |
| yes and no | 01/01/70 00:00 | |
| What?? | 01/01/70 00:00 | |
| That's how one learns things. | 01/01/70 00:00 | |
| 485 connection with 8051 | 01/01/70 00:00 | |
| how to connect pin nos 2(RE) & 3(DE) | 01/01/70 00:00 | |
| I mean | 01/01/70 00:00 | |
| once again | 01/01/70 00:00 | |
| 485 connection with 8051 | 01/01/70 00:00 | |
| Hai | 01/01/70 00:00 | |
| 485 chip | 01/01/70 00:00 | |
| Delay | 01/01/70 00:00 | |
| totally imprecise not enough/too much | 01/01/70 00:00 | |
| Sure | 01/01/70 00:00 | |
which was made before yours! | 01/01/70 00:00 | |
| Sure | 01/01/70 00:00 | |
| ??? | 01/01/70 00:00 | |
| Have you considered reading the datasheets? | 01/01/70 00:00 | |
| have a look at SN75176B | 01/01/70 00:00 | |
| anyone would be foolish attempting 485 | 01/01/70 00:00 |