| ??? 03/03/08 12:32 Read: times |
#151806 - uC -> RTU Slave (OK) ; RTU Slave -> uC (FAIL) Responding to: ???'s previous message |
Hi,
Thanks for the advise. In fact, I managed to get a scope just now to probe the TxD and RxD signal. I spotted that the transmit part is working fine as the RTU slave managed to reply my uC RTU instruction. I also double confirm that the RTU slave didn't reply my uC RTU instruction which I purposely put a wrong CRC value. For the receive side, the data is send in a continous bytes which adhere the RTU timing requirement. But this continous bytes continously triggered the serial interrupt. Its too fast which cause my uC don't have any time to process it. My DS89C450 uC only have 8 bit RxD buffer which it will always overwrite by the last RTU value. So I am hoping you can advise me on handling this receiving part. Thanks a lot in advance. Chin Liang |
| Topic | Author | Date |
| MODBUS RTU for 8051/DS89C450 | 01/01/70 00:00 | |
| How to post source code | 01/01/70 00:00 | |
| Formatted Source Code | 01/01/70 00:00 | |
| Looks like translated PIC code! | 01/01/70 00:00 | |
| So where is the problem? | 01/01/70 00:00 | |
| More details... | 01/01/70 00:00 | |
| How did you test your VC++ app...? | 01/01/70 00:00 | |
| uC -> RTU Slave (OK) ; RTU Slave -> uC (FAIL) | 01/01/70 00:00 | |
| RE:8 bit buffer | 01/01/70 00:00 | |
| Problem? | 01/01/70 00:00 | |
RE:8 bit buffer | 01/01/70 00:00 | |
| RTU Communication is working! | 01/01/70 00:00 |