Chapter 6. Serial I/O, SNP & RTU Protocols
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PACSystems* RX7i, RX3i and RSTi-EP CPU Reference Manual
GFK-2222AD
6.1.5
COMMREQ Command Block Parameter Values
The following table lists common parameter values that are used within the COMMREQ command blocks
for configuring a serial port. All values are in decimal.
Parameter
Values
Protocol Selector
1 = SNP
3 = RTU
5 = Serial I/O
7 = Message Mode
Data Rate
0 = 300
1 = 600
2 = 1200
3 = 2400
4 = 4800
5 = 9600
6 = 19200
7 = 38400
8 = 57600
9 = 115200
Parity
0 = None
1 = Odd
2 = Even
Flow Control
0 = Hardware [RTS / CTS]
1 = None
2 = Software [XON / XOFF] (Serial I/O only)
Bits Per Character
0 = 7 bits
1 = 8 bits
Stop Bits
0 = 1 stop bit
1 = 2 stop bits
Duplex Mode
0 = 2-wire
1 = 4-wire
2 = 4-wire transmitter always on
Turnaround Delay (SNP only)
0 = none
1 = 10ms
2 = 100ms
3 = 500ms
Timeout (SNP only)
0 = Long (8 sec)
1 = Medium (2 sec)
2 = Short (500ms)
3 = None (200ms)
