PACSystemsâ„¢ RX3i and RSTi-EP CPU Reference Manual Section 6
GFK-2222AK October 2019
Serial I/O, SNP & RTU Protocols 148
2. A write request was initiated previously and transmission of the specified number of
characters is complete or a time-out has elapsed.
The status returned by the function indicates the event or events that have completed.
More than one condition can occur simultaneously, if both a read and a write were
initiated previously.
6.2.9.1 Example Command Block for the Read Port Status Function
6.2.9.2 Port Status
The port status consists of a status word and the number of characters in the input buffer
that have not been retrieved by the application (characters which have been received and
are available).