| ??? 12/02/09 21:34 Read: times |
#171410 - Also RTU Framing Responding to: ???'s previous message |
As far as I can tell, the subject of RTU framing has not yet been mentioned.
Although some Modbus controllers are lax in this aspect, some are not- According to the spec, you need at least 3.5 character times between Modbus messages for baud rates of less than 19200. If the time between characters is greater than 1.5 character times, the message should also be rejected. Above 19200 these periods change to constants of 1.75mS between frames and 750uS between characters. -Aubrey |
| Topic | Author | Date |
| Modbus | 01/01/70 00:00 | |
| What testing have you done? | 01/01/70 00:00 | |
| Don't use hyperterminal | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| Still lots of debugging left | 01/01/70 00:00 | |
| Modbus | 01/01/70 00:00 | |
| Not very helpful | 01/01/70 00:00 | |
| Modbus | 01/01/70 00:00 | |
| Still need to break the problem down into smaller steps | 01/01/70 00:00 | |
| Modbus | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| Parity | 01/01/70 00:00 | |
| Oscilloscope results? | 01/01/70 00:00 | |
| open source | 01/01/70 00:00 | |
| Also RTU Framing | 01/01/70 00:00 | |
| Framing, addressing etc has been discussed | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| Bad CRC order!! | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
| Don't know why, | 01/01/70 00:00 | |
| Comparison with something known working | 01/01/70 00:00 | |
| what device address | 01/01/70 00:00 | |
| modbus | 01/01/70 00:00 | |
I would do this... | 01/01/70 00:00 |