Data Transmission; Data Reception - Husky MP2500 Manual

continue to be sent down the line. Any protocols selected will continue to be
observed.

13.3.2 Data Transmission

While using MP2500 communications, transmitted data is initially written to
a 256 character transmit buffer. Characters are removed from this buffer by
the interrupt-driven communications package as and when the remote
system is ready to receive them.
If the buffer becomes full, then the application is held up until the characters
are sent (or a timeout occurs).
If a timeout or other communications failure is detected, it is reported and
execution of the user program is suspended until the user acknowledges
the error.

13.3.3 Data Reception

While using MP2500 communications, received data is placed initially in a
256 character wrap-round receive buffer.
If the buffer becomes full, the protocol or handshaking which have been
selected should prevent reception of further data. However, if the remote
system does not stop transmitting when requested to (ie does not respond
correctly to the protocol or handshaking selected), the later characters
overwrite the earlier characters.
An application reads data from this receive buffer. If there is sufficient data
in the buffer, then it will be returned immediately. If there is insufficient data,
the MP2500 will wait for it to arrive (or until a timeout occurs).
Reception of data is completely transparent to the application being run.
Data may be sent at any time and the communications protocols will
function as configured.
If a timeout or other communications failure is detected, execution of the
user program will be suspended until the user acknowledges the error. (See
section 14.11.)
122 H MP2500 System Developer's Guide
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