Allen-Bradley 160-DN2, Руководство пользователя, Страница: 43 / 116

Publication 0160-5.18 - June 2003
Using 160-DN2 with DeviceNet Scanner 6-5
Selecting Input and Output
Assemblies for I/O Messaging
The DeviceNet Specification defines Assembly Objects as objects
that “bind attributes of multiple objects to allow data to or from each
object to be sent over a single connection.” The 160-DN2 module
uses Assembly Objects to send data to and from a Scanner over an I/O
connection. The terms
input and output are defined from the scanner’s
point of view. Therefore, Output Assemblies are information that is
output from the scanner and consumed by the 160-DN2 module.
Input Assemblies are the status information produced by the module
and consumed as input by the scanner.
The 160-DN2 module lets you select between various Input and
Output Assemblies, thereby choosing the data format of the messages
that are passed back and forth between the module and the scanner on
the I/O connection. The Assemblies that are supported are numbered
and are part of a DeviceNet-defined “Motor Control Hierarchy.” This
lets drives directly replace motor starters or contactors on a network
without the need to reprogram the scanner. Refer to
Appendix B ,
pages B-23 to B-28 for information on the data format of all Bulletin
160 Assemblies.
DeviceNet parameters P107 - [Output Assembly] and P108 - [Input
Assembly] must be programmed with the proper output or input
assembly. Refer to Chapter 5 , Page 5-4 for available selections.
Use the information that is appropriate to your particular system to
determine which Input and Output Assembly to use. See
Appendix B
for descriptions of all Input and Output Assemblies.
To illustrate how to select the Assemblies, we will use Output
Assembly 103 and Input Assembly 104 as examples. The data formats
for these Assemblies are:
Table 6.A Output Assembly 103 Data Format
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 N/A N/A Direction Direction Clear Faults N/A Start Stop
1 N/A Reference
Select Reference
Select Reference
Select N/A N/A N/A N/A
2 Scale Speed Reference (Low Byte)
3 Scale Speed Reference (High Byte)
Table 6.B Input Assembly 104 Data Format
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 Fault N/A Decel Accel Rot Dir Cmd Dir Running Enabled
1 Freq
Source Freq
Source Freq
Source Freq
Source Local Local Local At Speed
2 Actual Speed Reference 0-32767
3 Actual Speed Reference 0-32767