Rockwell Automation 1769-L23E-QB1B_L23E-QBFC1B_L23-QBFC1B CompactLogix Packaged Controllers Quick Start and User Manual - Manual (Page 207)

Publication IASIMP-QS010B-EN-P - October 2009 207
Embedded I/O Chapter 3
High-speed Counters Both the 1769-L23-QBFC1B and 1769-L23E-QBFC1B packaged controllers
provide high-speed counter functionality similar to that of the 1769-HSC
module.
While many features of the 1769-HSC module are available with the embedded
high-speed counters, some of the features of the 1769-HSC module are not
available with the embedded high-speed counters of the CompactLogix
packaged controllers. Features not available on the embedded high-speed
counters include rate/timer functions and limited output range control (4
ranges instead of the 16 available with the 1769-HSC module).
This section provides wiring diagrams, configuration procedures, and tag
descriptions for the embedded high-speed counters.
High-speed Counters Wiring Diagrams
This section describes wiring options for the high-speed counter terminals of
the 1769-L23-QBFC1B and 1769-L23E-QBFC1B packaged controllers.
Input Wiring
The embedded high-speed counter uses differential inputs. Therefore, two
input terminals are required for each input point. For example, the A0+ and
A0- terminals are required for input point A0. Each input point is isolated
from other input points, the packaged controller, and the entire output
terminal group.
The inputs are compatible with standard differential-line driver output devices
as well as single-ended devices such as limit switches, photo-eyes, and
proximity sensors. Examples of differential and single-ended circuits are
shown in these wiring diagrams.