Rockwell Automation 20-750-PBUS Profibus DPV1 Option Module - Manual (Page 61)

Rockwell Automation Publication 750COM-UM004B-EN-P - September 2012 61
Acyclic Messaging Chapter 6
Figure 11 - Acyclic Class 1 Read for Parameter 1 - [Output Frequency]
When the message response successfully returns, the data for the Output
Frequency parameter will be placed in the tags
MVI56PDPMV1.Mailbox.AcyclicRead.In.Data[] byte array. In the controller
program, the return message data may be copied to a locally configured program
tag, and converted by correctly assigning the data type for the Local tag to which
the data returned from the read request matches. In this drive parameter 1 -
[Output Frequency] example, the local tag's data type should be a floating point
or a ‘REAL’ data type.
Acyclic Class 1 Read response data can be viewed as shown in Figure 12 .
Figure 12 - Acyclic Class 1 Read Response Data for Parameter 1 - [Output Frequency]
Figure 13 shows the RSLogix ladder logic example, that may be used to interface
the MVI56-PDPMV1 module’s functional block and perform continuous DPV1
Acyclic Read operations.