Hello again,
One of my developers is having the following problem. I'm clueless. any
ideas? OS is DU4.0D
Thanks,
John E. Taylor
john.e.taylor_at_L-3com.com
L-3 Communications
Salt Lake City, Utah
> We are attempting to communicate to an external device using the Auxiliary
> serial port (tty01) and RS485 at 38.4 baud. The size of the max message
> size is 512. The data is being sent from our process on the Alpha to the
> external device. The external device is echoing the message back. Our
> process on the Alpha is recognizing input but is only receiving 256 words
> of the message. Subsequent reads by the Alpha process does not receive
> any more data, it appears to have been lost. We have changed the
> interface to an RS232 with the same results. When the baud rate is
> dropped to 19.2 it works fine. The documentation suggests that the limit
> is 19.2 baud but we have been told by digital that it should work at 38.4
> baud. My guess is that either the chip or the driver has a buffer
> limitation that is compounded by the higher baud rate. The question is
> can the receiving chip/driver buffer size be increased to allow for
> receiving the entire frame.
> We are using a Alpha 5/480 SBC which has a 82C42PE and FDC37C665GT Super
> I/O chip.
Received on Fri May 21 1999 - 19:25:57 NZST