Rockwell Automation 2711-K9A10_K9C10_T9A10_T9C10 DeviceNet Communications User Guide - Manual (Page 15)

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Publication 2711-6.0.4
Explicit Client
The PanelView can also communicate using peer-to-peer Explicit-Client
messaging, where the PanelView (Client) initiates the connections and obtains
data from other devices (Server). Connections to other devices are created with
Tag Form addresses and use explicit messages to read and write values to other
DeviceNet nodes. PanelView Explicit-Client communications only support
transactions with UCMM capable network devices.
Only Get_Attribute_Single and Set_Attribute_Single commands are supported.
For PanelView objects with explicit client addressing:
• Get_Attribute_Single (server code 0xOE)
The PanelView sequentially scans values addressed to PanelView objects in the
current screen (or global objects) and reads data from the external server device.
• Set_Attribute_Single (server code 0x10)
The PanelView sends values to the external device when a change of state is
detected on that input.
Output data is acquired similar to polling and input data is sent on Change of State
(COS). The location of the data in the DeviceNet Server device must be specified
in the PanelView data tags. Data locations on the server device are specified by
providing the Node Address, Class, Instance, Attribute and the Byte/Bit Offset.
The Class, Instance and Attribute are provided in the user documentation of the
device the PanelView is communicating with. Refer to Appendix A for the
Packet Bytes and Offsets required for read and write tags.
The following illustrates how Explicit-Client messaging functions:
Write Tag
Write Tag
Write Tag
Read Tag
Read Tag
Read Tag
Write Tag
PanelView
Server Device 1
(Sensor, Drive, ...)
Server Device 2
(Sensor, Drive, ...)
Server Device
(Sensor, Drive, ...)
Explicit-Client Message Tags
Server Res
ponse
Explicit ‘SET
’ Message
Ex
plic
it ‘
GE
T’ M
ess
age
Ser
ver
Re
spo
nse
For Read tags:
PanelView (client) device initiates communications with Explicit
‘GET’ Message to obtain input data from the server device. The
server device responds by sending data.
For Write tags:
PanelView (client) device sends data using an Explicit ‘SET’
Message to set output data. The server device responds that data
has been received.