Example Commreq Command Blocks For Serial Port Setup Function - GE PACSystems RX7i Reference Manual

6.1.6 Example COMMREQ Command Blocks for Serial Port Setup function

The following COMMREQ command blocks provide examples for configuring the various protocols. All
values are in decimal unless followed by an H indicating hexadecimal.
Note that an example is not provided for Message Mode, but it can be setup with a command block
similar to the one for Serial I/O, with a value of 7 for the protocol selector.
Example COMMREQ Command Block for Configuring SNP Protocol
Values
Address 16
Address + 1 0 = No Wait (WAIT mode not supported)
Address + 2 0008 = %R, register memory
Address + 3 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)
Address + 4 not used
Address + 5 not used
Address + 6 FFF0H
Address + 7 1 = SNP
Address + 8 0 = Slave
Address + 9 See COMMREQ Command Block Parameter Values.
Address + 10 0 = None, 1 = Odd, 2 = Even
Address + 11 not used (SNP always chooses NONE by default)
Address + 12 0 = None, 1 = 10ms, 2 = 100ms, 3 = 500ms
Address + 13 0 = Long, 1 = Medium, 2 = Short, 3 = None
Address + 14 not used (SNP always chooses 8 bits by default)
Address + 15 0 = 1 Stop Bit, 1 = 2 Stop bits
Address + 16 not used
Address + 17 not used (SNP always chooses 4-wire mode by default)
Address + 18 user-provided
Address + 19 user-provided
Address + 20 user-provided
Address + 21 user-provided
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The device identifier for SNP Slave ports is packed into words with the least significant character in the least significant byte
of the word. For example, if the first two characters are "A" and "B," the Address + 18 will contain the hex value 4241.
GFK-2222AD
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April 2018
Chapter 6. Serial I/O, SNP & RTU Protocols
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
Device identifier bytes 1 and 2
Device identifier bytes 3 and 4
Device identifier bytes 5 and 6
Device identifier bytes 7 and 8
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