Example of i/o messaging, Example of i/o messaging -2 – Rockwell Automation 1329I DeviceNet Option FRN 1.XXX User Manual

Page 40

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5-2

Using I/O Messaging

Example of I/O Messaging

For example, Output Assembly 21 uses the following data format:

Input Assembly 71 uses the following data format:

Figure 5.1

illustrates how data in Output Assembly 21 and Input Assembly

71 will be transmitted between a 1329I unit and an SLC processor. Notice
that the terms input and output are defined from the scanner’s point of view.
Also notice that explicit messaging can be transmitted as well.

Figure 5.1 Example I/O Image

Byte

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

NetRef

Net

Control

Fault
Reset

RunRev

RunFwd

1

Not Used

2

Speed Reference RPM (Low Byte)

3

Speed Reference RPM (High Byte)

Byte

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

At
Reference

RefFrom
Net

CtrlFrom
Net

Ready

Running
Reverse

Running
Forward

Faulted

1

Not Used

2

Speed Actual RPM (Low Byte)

3

Speed Actual RPM (High Byte)

SLC

Scanner

1329I Unit and DeviceNet Option

Devic

eNe
t

Output
Image
(Write)

Input
Image
(Read)

Explicit

Message

Handler

Explicit

Message

Buffer

0 - Logic Status
1 - Not Used
2 - Actual Speed (Low Byte)
3 - Actual Speed (High Byte)

0 - Logic Command
1 - Not Used
2 - Speed Reference (Low Byte)
3 - Speed Reference (High Byte)

Byte

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