Rockwell Automation 20-COMM-R Remote I/O Adapter - Manual (Page 63)

Using Block Transfer Messaging 5-5
20-COMM-R Remote Adapter I/O User Manual
Publication 20COMM-UM004D-EN-P
Executing Block Transfers
for Explicit Messages
1. Enter data into the program.
Data must be entered into a data file for a program to run. The data file
that is used depends on your controller and application.
2. Run the program.
When executing a Block Transfer message, the program must monitor
the Block Transfer Status word (Word 0) in the Discrete I/O Image. Its
bits are defined as shown in the following table.
Figure 5.2 illustrates the events of a successful Block Transfer.
Figure 5.2 Block Transfer Timeline
Bits Name and Description
0…7 Node Adapter Chip
These bits are used by the node adapter chip to communicate with the master on the
network. The master application should not use these bits.
8 DATA_VALID
0 = Data from the drive is not valid.
1 = Data from the drive is valid.
9 Message Block Transfer Write Available
0 = Not ready
1 = Ready to receive a Block Transfer write.
10 Message Block Transfer Read Available
0 = Not ready
1 = Data is available for a Block Transfer read.
11 Message Block Transfer Error
0 = Block Transfer message succeeded.
1 = Block Transfer message failed.
12…15 Reserved
Do not use.
Events
Bit 8
Bit 9
Bit 10
0
1
0
1
0
1
Bit
Status
(0
=
Off
, 1
=
On)
Bit 11
0
1
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