Omron CS1W-CRM21 - Message Communications; Overview; FINS Message Communications

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Message Communications Section 6-1
6-1 Message Communications
The message communications function sends and receives data between
nodes on a CompoNet Network, i.e., between the PLC's CPU Unit and the
Master Unit and between the PLC's CPU Unit and CompoNet Slave Units.
Message communications are used to read and write special data, such as
time or error history information, and to control operation, e.g., by force-set-
ting/resetting bits. Message communications are performed whenever
required, i.e., when the conditions set for their execution are satisfied.
There are two types of message communications: FINS message communi-
cations and explicit message communications.
6-1-1 Overview
6-1-2 FINS Message Communications
Messages using FINS commands can be exchanged with CompoNet Master
Units that support FINS messages.
CS/CJ-series CompoNet Master Units can freely exchange message commu-
nications with nodes on other networks (such as Controller Link, SYSMAC
LINK, and Ethernet). Communications are possible across a maximum of
three network layers. Routing tables must be registered, however, in the CPU
Unit of each PLC on the network, including the local and relay network tables.
CompoNet Master Units are not included in those routing tables.
FINS communications are possible across a maximum of three layers,
with CompoNet Master Units at the ends.
FINS message
communications
Explicit message
communications
Overview Message communications
developed by OMRON using the
FINS protocol
General-purpose message com-
munications using the Compo-
Net Network protocol
Remote devices OMRON PLCs CompoNet Slave Units
Features • FINS commands can be sent
and received to implement a
wider range of services than is
possible with explicit mes-
sages.
• FINS commands provide trans-
parent message communica-
tions with nodes on other
OMRON networks (Controller
Link, SYSMAC LINK, Ethernet,
and DeviceNet) across a maxi-
mum of three network layers.
• Explicit messages can be
received from OMRON PLCs
and they can be sent to Com-
poNet Slave Units.
Ethernet Unit
CS/CJ-series
CPU Unit
DeviceNet Unit
CS/CJ-series
CPU Unit
Ethernet Unit
DeviceNet Master Unit
Controller Link Unit
CompoNet Master Unit
Controller Link Unit
CS/CJ-series
CPU Unit
DeviceNet
Controller Link