Rockwell Automation 2711-K9A10_K9C10_T9A10_T9C10 DeviceNet Communications User Guide - Manual (Page 11)

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Publication 2711-6.0.4
I/O Slave Messaging The I/O slave message connections use the pre-defined Master/Slave connection
set. Exchanged data is grouped in Assembly Instances created using the
PanelBuilder Tag Editor. The first input instance and the first output instance are
exchanged using DeviceNet I/O slave messages. The PanelView supports a
maximum of 64 input and 64 output words. The number of words exchanged is
determined by the Communication Setup dialog in PanelBuilder and the Master
(scanner) device DeviceNet configuration.
Data at the PanelView tag addresses can be mapped to any location in the
DeviceNet scanner but must be a continuous block of 1- 64 input or output words.
Change-of-State, Cyclic and Polled I/O modes are supported. Strobed I/O
messaging is not supported by the PanelView.
DeviceNet PanelView terminals support the following types of I/O messaging
when configured in the DeviceNet scanner.
Polling
The DeviceNet scanner initiates communications with the PanelView terminal by
sending a Polled Request. The PanelView responds to the request by providing the
requested data. Data is sent by the PanelView at intervals determined by the
ladder logic program and/or the Interscan Delay of the scanner (not the PanelView
Interscan Delay setting).
Change of State (COS)
The DeviceNet scanner establishes the connection with the PanelView terminal.
The exchange of data is Asynchronous. Output data is sent to the PanelView from
the scanner only when the data changes. The PanelView terminal sends Input data
back to the scanner only when the data changes. Acknowledged/Unacknowledged
modes are available (see ‘Notes’ on the next page).
Cyclic
Data is exchanged between the PanelView terminal and scanner at the Heartbeat
Rate. The Heartbeat Rate is set using a DeviceNet Manager tool, such as
RSNetwork for DeviceNet, during network setup.