ProSoft Technology MVI69-GSC User Manual
Page 76

Reference
MVI69-GSC ♦ CompactLogix or MicroLogix Platform
User Manual
Generic ASCII Serial Communication Module
Page 76 of 102
ProSoft Technology, Inc.
September 24, 2010
Data contained in this database is paged through the input and output images by
coordination of the CompactLogix ladder logic and the MVI69-GSC module's
program. Up to 60 words of data can be transferred from the module to the
processor at a time. Up to 60 words of data can be transferred from the
processor to the module. The read and write block identification codes in each
data block determine the function to be performed or the content of the data
block. The block identification codes used by the module are listed below:
Block Range
Descriptions
0 to 127
Normal Data Blocks for Read and Write
9998
Warm-boot control block
9999
Cold-boot control block
Each image has a defined structure depending on the data content and the
function of the data transfer.
Normal Data Transfer
Normal data transfer includes the paging of the user data to and from the
module’s ports and bringing in status data. These data are transferred through
read (input image) and write (output image) blocks. The structure and function of
each block is discussed in the following topics: