Example of i/o messaging, Example of i/o messaging -2 – Rockwell Automation 1329I DeviceNet Option FRN 1.XXX User Manual
Page 40

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:
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