Rockwell Automation 2755-SNx Adaptascan Bar Code Readers - Manual (Page 333)

17–11 Communicating with PanelView 900
t
Terminals on a DeviceNet Network
Publication 2755-6.8
All PanelBuilder screen control or display objects are assigned a tag
when an application is developed. The tag specifies an address, data
type, initial value, etc. for the data assigned to the control or display
object. The Tag Editor for DeviceNet objects consist of three
dialogs depending upon the message type selected.
Server Explicit and I/O Slave Messaging
The PanelView can exchange data with logic controllers, motor
drives, bar code readers, etc. over a DeviceNet network. The
PanelView acts as a DeviceNet compliant UCMM-capable slave
supporting Explicit and I/O Slave messaging. Change-of-State /
Cyclic and Polled I/O modes are supported. Strobed I/O messaging
is not supported by the PanelView.
The I/O slave message connections uses the pre-defined
Master/Slave connection set. Exchanged data is grouped in
Assembly Object instances created using the PanelBuilder tag editor.
The first input instance and the first output instance are exchanged
using DeviceNet’s I/O slave messages with a maximum of 64 input
and 64 output words exchanged. If additional instances are
configured, they can only be accessed by an Explicit Messaging
Client device using messages directed to the corresponding
Assembly Object Instance (Class 4, Attribute 3).
Notes on Using Server Explicit and I/O Slave Messaging:
•
The I/O size specified in the PanelView terminal must match the
I/O size expected by the DeviceNet scanner.
•
Both acknowledged and unacknowledged Change-of-State /
Cyclic modes are allowed. If acknowledgement is used, no data
is returned. The Polled + COS option is allowed but the polled
response data and the COS data are from the same assembly.
•
The PanelView has only one general purpose Explicit message
connection available at a time to an external client device. Be
aware of this limitation when creating applications requiring
multiple Explicit message server connections to a PanelView.
•
Use of COS or Cyclic I/O connections is highly recommended
over Polled I/O for I/O sizes in excess of 32 words.
•
Whenever possible, use COS or Cyclic I/O connections to
minimize network I/O traffic.
PanelView Message Types