Chapter 6. Serial I/O, SNP & RTU Protocols
212
PACSystems* RX7i, RX3i and RSTi-EP CPU Reference Manual
GFK-2222AD
6.2.6
Initialize Port Function (4300)
This function causes a reset command to be sent to the specified port. It also cancels any COMMREQ
currently in progress and flushes the internal input buffer. RTS and DTR are set to inactive.
Example Command Block for the Initialize Port Function
Value
(decimal)
Value
(hexadecimal)
Meaning
Address
0001
0001
Data block length
A1
0000
0000
NOWAIT mode
A2
0008
0008
Status word memory type (%R)
A3
0000
0000
Status word address minus 1 (%R0001)
A4
0000
0000
Not used
A5
0000
0000
Not used
A6
4300
10CC
Initialize port command
Operating Notes
Remote COMMREQs that are cancelled due to this command executing will return a COMMREQ status
word indicating request cancellation (minor code 12H).
Caution
If this COMMREQ is sent when a Write Bytes (4401) COMMREQ
is transmitting a string from a serial port, transmission is halted.
The position within the string where the transmission is halted
is indeterminate. In addition, the final character received by the
device to which the CPU is sending is also indeterminate.
