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UART Half duplex operation over RS485

Question asked by OLEG KARPENKO on Jun 1, 2009
Latest reply on Jul 15, 2010 by OLEG KARPENKO

Hi,

I have another UART question:

I need to turn off RS485 TX drivers when TX buffer emptied out. It has to be  done quickly, 10mS delay after last char left UART is already too long. 

So far I found only one way of doing it:

IO_IOCTL_SERIAL_TRANSMIT_DONE check through ioctl.

So far I had very bad lack with this ioctl feature, probably because my task priority issues.

Is MQX offer any callback functions or IRQ vectors for TX Over condition? Can I use any hardware flow control signals? I saw one topic which suggested that hardware flow control is not a working feature. Any suggestions?

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