Chapter 6. Serial I/O, SNP & RTU Protocols
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Example COMMREQ Data Block for Configuring Serial I/O Protocol
0 = No Wait (WAIT mode not supported)
0008 = %R, register memory
Status Word Pointer Memory Type
Zero-based number that gives the address of the
COMMREQ status word (for example, a value of 99 gives
an address of 100 for the status word)
Status Word Pointer Offset
Maximum Communication Time
Command Word (serial port setup)
See COMMREQ Command Block Parameter Values.
0 = None, 1 = Odd, 2 = Even
0 = Hardware, 1 = None, 2 = Software
0 = 1 stop bit, 1 = 2 stop bits
0 = 2-wire, 1 = 4-wire, 2 = 4-wire transmitter always on