Rockwell Automation 1794-XXXX FLEX I/O High-Density Analog Modules - Manual (Page 76)

Publication 1794-UM062A-EN-P - September 2012
68 Module Programming
• configure the module
• read data from the module
• update the module output channels (if used)
These programs illustrate the minimum programming required for
communication to take place.
PLC-2 Programming
The 1794 analog I/O modules are not recommended for use with PLC-2 family
programmable controllers due to the number of digits needed for high
resolution. In addition, the data returned from the analog-to-digital converter in
the module is 12-bit resolute. This value is left-justified into a 16-bit field,
reserving the most significant bit for a sign bit.
PLC-3 Programming
Block transfer instructions with the PLC-3 processor use one binary file in a data
table section for module location and other related data. This is the block transfer
control file. The block transfer data file stores data that you want transferred to
your module (when programming a block transfer write) or from your module
(when programming a block transfer read). The address of the block transfer data
files are stored in the block transfer control file.
The same block transfer control file is used for both the read and write
instructions for your module. A different block transfer control file is required
for every module.
A sample program segment with block transfer instructions is shown in
Figure PLC-3 Family Sample Program Structure for a 1794-IE8 Module .