GE PACSystems RX7i Reference Manual page 218

Example COMMREQ Data Block for Configuring Serial I/O Protocol
Values
Address 12
Address + 1 0 = No Wait (WAIT mode not supported)
Address + 2 0008 = %R, register memory
Zero-based number that gives the address of the
Address + 3 COMMREQ status word (for example, a value of 99 gives
an address of 100 for the status word)
Address + 4 not used
Address + 5 not used
Address + 6 FFF0H
Address + 7 5 = Serial I/O
Address + 8 not used
Address + 9 See COMMREQ Command Block Parameter Values.
Address + 10 0 = None, 1 = Odd, 2 = Even
Address + 11 0 = Hardware, 1 = None, 2 = Software
Address + 12 not used
Address + 13 not used
Address + 14 0=7 bits, 1=8 bits
Address + 15 0 = 1 stop bit, 1 = 2 stop bits
Address + 16 not used
Address + 17 0 = 2-wire, 1 = 4-wire, 2 = 4-wire transmitter always on
GFK-2222AD
Chapter 6. Serial I/O, SNP & RTU Protocols
April 2018
Meaning
Data Block Length
WAIT/NOWAIT Flag
Status Word Pointer Memory Type
Status Word Pointer Offset
Idle Timeout Value
Maximum Communication Time
Command Word (serial port setup)
Protocol
Port Mode
Data Rate
Parity
Flow Control
Turnaround Delay
Timeout
Bits per Character
Stop Bits
Interface
Duplex Mode
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