Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules - Manual (Page 189)

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 189
Tag Definitions Appendix B
Fast Input Module Tags The ControlLogix 1756-IB16IF fast input module has four types of tags:
• Configuration— Structure of data sent from the controller to the I/O
module upon powerup.
• Input— Structure of data continually sent from the I/O module to the
controller or a listening peer module containing the current operational
status of the module.
• Output— Structure of output data processed by the input module.
• Event— Structure of event data continually sent from the I/O module to
the controller or a listening module containing the current operational
status of the module.
Fast input modules use array data structures. Array data structures differ from the
flat data structures of other digital I/O modules. For more information, see
Array
Data Structures on page 211 .
IMPORTANT In RSLogix 5000 software, version 18.02.00 and 19.01.00, output tag
information is sent to the 1756-IB16IF module only at the RPI rate defined
during configuration. For optimal performance, use an Immediate Output (IOT)
instruction.
For example, the rung shown below contains an IOT instruction for a fast input
module in slot 3. Add a similar rung to your last routine within the Main Task to
mimic normal output tag processing.
IMPORTANT The Module Definition column in each table lists the connection type and input
data type combinations that are required to create the corresponding tag. For
more information about defining connection and input data types, see
Create a
New Module on page 129 .