Omron OMNUC G5 R88M-K series User Manual page 201

Improving Control I/O Signal Noise Resistance
Positioning can be affected and I/O signal errors can occur if control I/O is influenced by noise.
 Use completely separate power supplies for the control power supply (especially 24 VDC) and the
external operation power supply. In particular, do not connect the 2 power supply ground wires.
 Install a noise filter on the primary side of the control power supply.
 If motors with brakes are being used, do not use the same 24-VDC power supply for both the
brakes and the control I/O. Additionally, do not connect the ground wires. Connecting the ground
wires may cause I/O signal errors.
 Keep the power supply for pulse commands and error counter reset input lines separated from the
control power supply as far as possible. In particular, do not connect the 2 power supply ground
wires.
 We recommend using line drivers for the pulse command and error counter reset outputs.
 Always use twisted-pair shielded cable for the pulse command and error counter reset signal lines,
and connect both ends of the shield cable to frame grounds.
 If the control power supply wiring is long, noise resistance can be improved by adding 1-
laminated ceramic capacitors between the control power supply and ground at the drive input
section or the controller output section.
 For open collector inputs/outputs, keep the length of wires to within 2 m.
OMNUC G5-Series AC Servo Drives Users Manual (Built-in MECHATROLINK-II communications type)
4-3 Wiring Conforming to EMC Directives
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