ProSoft Technology MVI56-GEC - Manual (Page 74)

Reference MVI56-GEC ♦ ControlLogix Platform
User Manual Generic ASCII Ethernet Communication Module
Page 74 of 108 ProSoft Technology, Inc.
October 8, 2010
The Block Sequence Number (word offset 249) is an index value that signals to
the ControlLogix processor that a new block is ready for processing. The ladder
logic must recognize a change in this value, and then process the data
encapsulated in the input image. If data is available for a server, the module
passes a block containing data received and the complete status data area to the
processor. The value at word 0 in the block contains one of the following values:
Value Description
-1 No receive data in block
0 Server 0 data in block
1 Server 1 data in block
2 Server 2 data in block
3 Server 3 data in block
4 Server 4 data in block
10 Client 0 data in block
11 Client 1 data in block
12 Client 2 data in block
13 Client 3 data in block
14 Client 4 data in block
Word 1 of the input image determines the number of bytes in the data area of the
block. This word only has significance if word 0 of the block is set to a valid
server index value (0 to 4), or client index value (10 to 14).