Omron OMNUC W R88A-NCW152-DRT, Руководство пользователя

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6 DeviceNet Communications
6.4.1 Remote I/O Communications
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6
6.4 Overview of Remote I/O and Explicit Message
Communications
This section provides an overview of Remote I/O communications and Explicit Message com-
munications.
6.4.1 Remote I/O Communications
Remote I/O communications function enable automatic exchange of I/O data between slaves
and a CPU Unit of the PC under which a DeviceNet Master Unit is mounted without special
programming in the PC.
Each slave is allocated words in the I/O Memory in the CPU Unit under which the
DeviceNet Master Unit is mounted. There are two methods of allocation: Free and fixed.
• User (I/O) Allocations:
The user can allocate desired words for Slave I/O in the DeviceNet I/O Areas (Input
Area, Output Area) in the I/O Memory. With the OMRON CS/CJ-series DeviceNet
Master Units, the settings can be made without a DeviceNet Configurator.
• Fixed I/O Allocations:
Slave I/O is allocated in the DeviceNet I/O Areas (Input Area, Output Area) in the I/O
Memory in the same order as the slave node addresses.
6.4.2 Explicit Message Communications
Explicit Message communications function use Explicit Messages defined for DeviceNet to
send and receive service requests. With a DeviceNet Unit, it is possible to receive service
requests using Explicit Messages from PCs with OMRON Master Units or from DeviceNet
masters by other vendors.
DeviceNet
DeviceNet Master Unit
CPU Unit
Remote I/O communications
Slaves