Omron CVM1-CLK21, Operation Manual

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110
Introduction Section 6-1
6-1 Introduction
A message service is a command/response system used for data transmis-
sion between nodes on a network, i.e., PC to PC, PC to computer, and com-
puter to PC). The message service can also be used to control operations,
such as mode changes. The message service is implemented by sending
commands from the user program. The following communications instructions
are used:
SEND and RECV: Instructions for sending and receiving data.
CMND: An instruction for sending FINS commands. Some FINS commands
are supported by Controller Link Units, and other FINS commands supported
by the PC’s CPU Unit.
Message service SEND/RECV instructions CMND instruction (FINS commands)
Source
node to
destination
node PC to PC
PC to com-
puter
Computer
to PC
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PC
User program
A program is not required for receiving
responses when the PC executes
SEND and RECV.
SEND
(Com-
mand for
CPU Unit)
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PC
(Com-
mand for
CPU Unit)
User program
A program is not required for receiving
responses when the PC executes
commands.
CMND
(Com-
mand for
Controller
Link Unit)
(Not supported by the
C200HX/HG/HE.)
Command
Command
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PC
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PC
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or CQM1H-
series PC
Computer
A program is required for sending and
receiving data with the computer.
A program is not required for receiving
responses when the PC executes commands.
Command
SEND
C200HX/HG/HE,
CS/CJ-series, CVM1, CV-se
ries, or CQM1H-series PC
(The equivalent of SEND/
RECV and CMND are sent
from the computer pro
gram.)
Computer
Command
(Command for
Controller Link
Unit or CPU
Unit)
Programming is required to receive
responses at the computer.