RX Buffer was being cleared with correct data in it. #94
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AFAIK, I don't think this is the right way to do it. Never had this issue before. |
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754B
Slave is abiding timings. We've checked this with a saleae logic analyzer. Clearing your buffer before sending solves this. and I can't see a reason why you would want to first send and then clear the receive buffer, since modbus is half duplex, a slave will never answer before the master sends so there isn't going to be rogue data in the buffer if you clear it beforehand. |
The transmit buffer was send before the RX buffer was being cleared. When a slave device was answering faster then the lib was clearing the buffer. correct data was being removed, and the packet was lost.