Omron G5 Series User Manual page 259

Improving Control I/O Signal Noise Resistance
Positional deviation 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 ground wires for these two power
supplies.
• Install a noise filter on the primary side of the control power supply.
• If motors with brake 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.
• Separate the power supply for the pulse command and error counter reset input lines from the control
power supply as far apart as possible. In particular, do not connect the ground wires for these two
power supplies.
• We recommend using line drivers for the pulse command and error counter reset outputs.
• For the pulse command and error counter reset signal lines, always use shielded twisted-pair cables
and connect each end of those shielded cables to the frame ground.
• If the control power supply wiring is long, noise resistance can be improved by adding 1-µF laminated
ceramic capacitors between the control power supply and ground at the drive input section or the
controller output section.
• For open-collector specifications, keep the length of wires to within two meters.
OMNUC G5-series (Pulse-train Input Type) AC Servomotors and Servo Drives User's Manual
4 System Design
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