Omron SYSMAC CJ - REFERENCE MANUAL 01-2008 Reference Manual page 1078

Network Instructions
W00000
W00001
Timing the Execution of
Network Instructions
Execution Communications Port
Condition Enabled Flag
Programming Example
A20201
Port: 1
A20201
Port: 1
Port: F
A Network Instruction just starts the communications processing when its
execution condition is established. The actual communications processing is
executed in the background in the "serial communications port servicing" por-
tion of peripheral servicing.
Directs the
start of
processing
only.
CMND
S
D
C
Stores results when
communications
processing is completed.
The communications processing is performed as follows:
1. If the corresponding Communications Port Enabled Flag (A20200 to
A20207) is ON when the execution condition is established, the system
performs the following processes:
• Turns OFF the port's Communications Port Enabled Flag and Commu-
nications Port Error Flag (A21900 to A21907).
• Sets the port's Communications Port Completion Code (A203 to A210)
to 0000.
• Reads the control words (beginning at C) and starts communications
processing (sending a FINS command or receiving a response.)
2. In the peripheral servicing's "serial communications port servicing" portion
of the cycle, the system composes a FINS command based on the oper-
ands (see note) and sends the FINS command to the Communications
Unit or other destination node.
Communications were previously enabled by
exclusively controlling operation using W00000 and
W00001.
Automatic
port alloca-
tion was add-
ed to the pro-
gram.
This instruction may, at times, use
communications port 1. Even if W00000
or W00001 is turned ON, A20201 will be
turned OFF by execution of this
PMCR(260) instruction, so neither of the
CMND(490) instructions will be executed.
Background communications
processing
Cycle
time
Cycle
time
Section 3-25
Composes a FINS
command based on the
command data and sends it.
The communications processing
(transmission and reception) is
performed in time-slices over several
cycles during the peripheral
servicing's "serial communications
port servicing" portion of the cycle.
Receives the response and stores
the information as response data.
The communications results are
reflected in the allocated Auxiliary
Area Flags.
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