| ??? 12/01/04 03:58 Read: times |
#82268 - Adapters Responding to: ???'s previous message |
Rustu:
Are you by chance using port powered RS232 to RS485 adapters? Port powered adapters are not too good for long distances and they are not good at driving standard termination resistors on the line. I recommend that you use externally powered adapters. Have you checked to make sure that the driver enables at all devices are OFF when they are supposed to be? I have had instances where a mistake like this was made and one driver was still able to overdrive several other drivers that were active to the extent of getting the requsite minimum 200 mV across the A & B lines so that receivers could still detect. If you had this situation it could appear to "work" for a small number of devices over a short distance. Michael Karas |
| Topic | Author | Date |
| rs485 distance problem | 01/01/70 00:00 | |
| ten ways to bulletproof RS-485 | 01/01/70 00:00 | |
| Sounds like a loading problem | 01/01/70 00:00 | |
| RS485 Cable | 01/01/70 00:00 | |
| RS485 Cable | 01/01/70 00:00 | |
| Adapters | 01/01/70 00:00 | |
| distance problem | 01/01/70 00:00 | |
| distance problem | 01/01/70 00:00 | |
| distance problem | 01/01/70 00:00 | |
all the above | 01/01/70 00:00 |