CompactLogix Controller     23
Rockwell Automation Publication 1769-IN082C-EN-P - February 2013
High-speed Counter Wiring Diagrams
• Input and output channels are isolated from the packaged controller. Input channels are 
isolated from one another; output channels are not.
• Shielded cable is required for high-speed input signals A, B, and Z. Use individually 
shielded, twisted-pair cable (or the type recommended by the encoder manufacturer) for 
lengths up to 300 m (1000 ft).
• Route field wiring away from any other wiring and as far as possible from sources of 
electrical noise, such as motors, transformers, contactors, and AC devices. 
• Routing field wiring in a grounded conduit can reduce electrical noise.
• If field wiring must cross AC or power cables, ensure that they cross at right angles.
• Make sure the system is properly grounded using these guidelines:
– This product is intended to be mounted to a well-grounded mounting surface such 
as a metal panel. Additional grounding connections from the packaged controller’s 
mounting tabs or DIN rail (if used) are only required when the mounting surface is 
non-conductive and cannot be grounded.
– Keep the shield connection to ground as short as possible.
– Ground the shield drain wire only at the HSC input end, except where 
high-frequency noise is present.
• To establish optimum accuracy, limit overall cable impedance by keeping cable as short as 
possible. Locate the packaged controller as close to input devices as your application 
permits. 
ATTENTION: Disconnect power before wiring the HSC removable terminal block. This includes 
sensor and packaged controller power.
ATTENTION: In environments where high-frequency noise may be present, it may be 
necessary to directly ground cable shields to earth at the removable terminal block end and via 
a 0.1μF capacitor at the sensor end.
Allen-Bradley Parts