Omron CJ1W-PNT21, Инструкции по эксплуатации

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1 Features and System Configuration
1-4
CJ-series PROFINET IO Controller Unit Operation Manual for NJ-series CPU Unit (W511)
TCP provides an error-free transmission of data from sender to receiver. It establishes a connection
between the two stations before the transmission is complete. This connection is monitored during
operation and disconnected after the transmission is complete.
UDP does not guarantee an error-free transmission of data. However, the UDP is connection-less.
Each message is an individual transmission. Because of the lack of overhead (connection establish-
ment, monitoring, etc.), this protocol is more suitable for time-critical applications.
 Communication Services
The PROFINET IO Controller Unit establishes a connection to its IO Devices based on the configu-
ration which has been given by the user. The Application Relation (AR) includes all data needed to
achieve this data exchange. A single AR can include multiple Communication Relations (CRs). For
implementation of different communication profiles, such as PROFIdrive, the PROFINET IO con-
tains special addressing elements. These elements are called Application Process Identifier (APIs).
The following CRs are possible for each API.
• IOCR, consisting of input, output or multicast
• Record data CR for exchange of acyclic data
• Alarm-CR for communicating alarms and other events
The data exchange between the IO Device and the IO Controller occurs in a poll cycle as configured
by the IO Controller. The user is capable to set this update cycle in the IO Controller configuration for
each of the IO Devices. This results in mutual monitoring of functional operability (watchdog func-
tion). All cyclic data is provided with a status that encodes the validity of the data.
Distributed field or IO Devices are integrated through PROFINET IO. This uses the usual I/O view of
PROFIBUS DP, whereby the I/O data of field devices are cyclically transmitted to the process image of
the CPU.
The PROFINET IO Device model is based on the PROFIBUS implementation, consisting of insertion
(slots) and groups of I/O channels (subslots). The characteristics of the field devices are described via
a General Station Description (GSD) on an XML basis.
The installation, monitoring and maintenance of PROFINET IO will be familiar to engineers accustomed
to PROFIBUS DP. The distributed field devices are allocated to a controller during configuration.
The focus of PROFINET IO is to have cyclic data exchange between a controller and multiple (often
simple) communication devices. The aim is to have high performance and ease to use. The experience
of the PROFIBUS fieldbus has been integrated into the PROFINET IO from user’s point of view.
The PROFINET IO distinguishes the following different device roles. Please note a single device can
have multiple roles.
1-1-3 PROFINET Distributed I/O