Rockwell Automation 1769-L23E-QB1B_QBFC1B_QBFC1B CompactLogix Packaged Controller Installation Instructions - Manual (Page 23)

CompactLogix Controller 23
Rockwell Automation Publication 1769-IN082C-EN-P - February 2013
High-speed Counter Wiring Diagrams
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Input and output channels are isolated from the packaged controller. Input channels are
isolated from one another; output channels are not.
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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).
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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.
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Routing field wiring in a grounded conduit can reduce electrical noise.
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If field wiring must cross AC or power cables, ensure that they cross at right angles.
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Make sure the system is properly grounded using these guidelines:
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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.
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Ground the shield drain wire only at the HSC input end, except where
high-frequency noise is present.
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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.
IMPORTANT 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.