Rockwell Automation 22-COMM-D DeviceNet Adapter User Manual

Page 59

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Using Explicit Messaging

6-3

The following table identifies the number of Explicit Messages that can
be executed at a time.

ControlLogix Message Requests and Responses

Scanner

Messages at
One Time

Refer To

1756-DNB 5

Figure 6.1

Box Description

Message Type
The message type must be CIP Generic.

Service Type/Service Code
The service type/code is the requested DeviceNet service. Available services
depend on the class and instance that you are using. Refer to

Appendix C

,

DeviceNet Objects

.

Class
The object type is a DeviceNet class. Refer to

Appendix C

,

DeviceNet Objects

, for

available classes.

Instance
The object ID is an instance of a DeviceNet class. Refer to

Appendix C

,

DeviceNet

Objects

, for available instances.

Attribute
The attribute is a class or instance attribute. Refer to

Appendix C

,

DeviceNet

Objects

, for available attributes.

Source Element
This box contains the name of the tag for any service data to be sent from the
scanner to the adapter and drive. A tag must be specified even if it is not used.

Source Length
This box contains the number of bytes of service data to be sent or received in the
message.

Destination
This box contains the name of the tag that will receive service response data from
the adapter and drive. A tag must be specified even if it is not used.

Path
The path includes the following:
• Name of the DeviceNet scanner.
• Communication port on the front of the 1756-DNB scanner. Always 2.
• Node address of the DeviceNet adapter. This is set with switches or

parameters in the DeviceNet adapter.

Tip: Click Browse to find the path or type in the name of a module that you
previously mapped.

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