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Thread Subject: Serial Port Issue - Buffer flush?

Subject: Serial Port Issue - Buffer flush?

From: ecnyx

Date: 7 Aug, 2008 23:17:16

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Hi All,

I have been struggling with communicating through serial port for
several days. Bottom line is I am unable to recieve data from my
hardware. I am using PortMon to monitor the communication lines. I
know the hardware works because it runs with the software that came
with it. The following is a log of one of my commands:

......
IRP_MJ_WRITE Length 11: 0A 04 00 00 00 00 00
00 00 04 00
IOCTL_SERIAL_SET_WAIT_MASK Mask: TXEMPTY CTS DSR RLSD BRK ERR RING
IRP_MJ_FLUSH_BUFFERS
IOCTL_SERIAL_SET_WAIT_MASK Mask: TXEMPTY CTS DSR RLSD BRK ERR RING
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_SET_WAIT_MASK Mask: CTS DSR RLSD BRK ERR RING
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
IOCTL_SERIAL_GET_COMMSTATUS InQueue: 0 OutQueue: 0
.......

Somehow, Matlab keeps flushing the buffer of the device. I use
fwrite.

My settings are:
Baud: 19200
Stopbit: 1
Parity: none
DataBits = 8
RTS = off
DTR = off

Can anyone shed light on this please?

Thanks!

Ellen

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