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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., PLC to PLC, PLC to computer, and
computer to PLC). The message service can also be used to control opera-
tions, such as mode changes. The message service is implemented by send-
ing 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 PLC’s CPU Unit.
Message service
SEND/RECV instructions
CMND instruction (FINS commands)
Source
node to
destination
node
PLC to PLC
PLC to
computer
Computer
to PLC
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PLC
User program
A program is not required for receiving
responses when the PLC executes
SEND and RECV.
SEND
(Com-
mand for
CPU Unit)
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PLC
(Com-
mand for
CPU Unit)
User program
A program is not required for receiving
responses when the PLC 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 PLC
CS/CJ-series, CVM1,
CV-series, or
CQM1H-series PLC
C200HX/HG/HE,
CS/CJ-series, CVM1,
CV-series, or CQM1H-
series PLC
Computer
A program is required for sending and
receiving data with the computer.
A program is not required for receiving
responses when the PLC executes commands.
Command
SEND
C200HX/HG/HE,
CS/CJ-series, CVM1, CV-series
or CQM1H-series PLC
(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.
Содержание C200HW-CLK21
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Страница 12: ...xiii TABLE OF CONTENTS Index 367 Revision History 373 ...
Страница 13: ...xiv ...
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Страница 57: ...32 Application Precautions Section 1 5 Example CX Programmer Response Timeout Setting ...
Страница 69: ...44 Message Service Procedure Section 2 2 ...
Страница 111: ...86 Constructing Networks with Repeater Units Section 3 4 ...
Страница 154: ...129 Setting Data Links Section 5 2 Device Information Setting Data Link Tables ...
Страница 261: ...236 Response Codes Section 6 7 ...
Страница 297: ...272 Message Delay Times Section 8 4 ...
Страница 353: ...328 Handling Precautions Section 9 6 ...
Страница 364: ...339 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Страница 365: ...340 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Страница 369: ...344 Standard Models Appendix A ...
Страница 391: ...366 Using the Relay Terminal Block Appendix C ...
Страница 397: ...372 Index ...
Страница 401: ...376 Revision History ...