| ??? 08/04/11 14:41 Read: times |
#183197 - input impedance Responding to: ???'s previous message |
Stefan Kanev said:
yes, i think. Input impedance will be > 1k, which is needed by RS232 standard.
The resulting impedance will be approx 1.4k (2k + 5k in parallel) but I found on this website "http://www.rs485.com/rs485spec.html" that the receiver input impedance should be from 3k to 7k ohms. So is it enought in my case? Or do I understand it wrong? Stefan Kanev said:
yes , i think , but ask Yourself - what signals catches that 'antenna'?
i think it is more likely cross-talk between RX and TX wires . So better cable is recommended too. or just disconnect cable from converter, not only from PC. regards I think so that it is cross talk. So maybe I should also use better cable as you suggest to avoid this situation. Unfortunately, it is not possile to disconnect the cable from the converter. It is fixed. Thank you very much. Regards |
| Topic | Author | Date |
| Problem with RS232/RS485 converter... | 01/01/70 00:00 | |
| More info please | 01/01/70 00:00 | |
| probably | 01/01/70 00:00 | |
| more info... | 01/01/70 00:00 | |
| yes,i think | 01/01/70 00:00 | |
| input impedance | 01/01/70 00:00 | |
| i'm wrong | 01/01/70 00:00 | |
| what is the right value? | 01/01/70 00:00 | |
| did You tryed capacitor? | 01/01/70 00:00 | |
| thanks... | 01/01/70 00:00 | |
| it works...! | 01/01/70 00:00 | |
| congrats | 01/01/70 00:00 | |
| shape | 01/01/70 00:00 | |
| dont | 01/01/70 00:00 | |
| It is OK. | 01/01/70 00:00 | |
| Hints... | 01/01/70 00:00 | |
| schema | 01/01/70 00:00 | |
| Repair... | 01/01/70 00:00 | |
| transils... | 01/01/70 00:00 | |
| RS485 | 01/01/70 00:00 | |
| Sample Schematic | 01/01/70 00:00 | |
| Thank you very much for the schema... | 01/01/70 00:00 | |
| AVX varistors... | 01/01/70 00:00 | |
| capacitor | 01/01/70 00:00 | |
| capacitors... | 01/01/70 00:00 | |
| GNDs | 01/01/70 00:00 | |
| 1992 | 01/01/70 00:00 | |
| Thanks... | 01/01/70 00:00 | |
Links... | 01/01/70 00:00 |