Omron CS1G/H-CPUxxH Instructions Manual page 893

Network Instructions
Execution Communications
condition Port Enabled Flag
Reset B
Local Node
Active Flag
Execution Communications
condition Port Enabled Flag
Reset D
Automatic Allocation of
Communications Ports
872
The following diagram shows an example of exclusive control.
Destination
Node Active
Flag
Communications
Port Enabled Flag
Communications
Port Error Flag
Same as above.
Overview
The following instructions all use one communications port (logical port)
between ports 0 to 7.
• Network Communications Instructions: SEND(090), RECV(098), and
CMND(490)
• PROTOCOL MACRO: PMCR(260)
In this section, all of the above instructions are referred to as Communications
Instructions.
Each communications port can be used by only one instruction at a time. The
following steps were previously necessary to use the communications ports.
• When programming, it was necessary to keep track of the communica-
tions ports that were being used to designate them in operands.
• In the ladder program, it was necessary to confirm the availability of com-
munications ports before using them.
Bit A remains ON while the communications
KEEP A instruction is being executed.
Copies the operand and control data to the
Creates op-
desired data area.
erand or
control data
with @MOV
or @XFER.
Executes the communications instruction.
@SEND,
@RECEIVE,
@CMND
Writes the reset input. (Reset B is turned
ON when the communications instruction
DIFU B
is completed.)
For Transmission Error Flag display
(Good if data is retransmitted.)
Exclusive control to prevent simulta-
neous execution:
KEEP C
Exclusive control prevents another
communications instruction from being
executed until the instruction above is
completed.
Section 3-25