Wiring For Conformity To Emc Directives - Omron OMNUC R88D-WT15HF User Manual

System Design and Installation
H Improving Encoder Cable Noise Resistance
The OMNUC W Series uses serial encoders, with phase-S signals from the encoder. The phase-S com-
munications speed is 4 Mbits/s.
In order to improve the encoder's noise resistance, take the following measures for wiring and installa-
tion.
• Always use the specified Encoder Cables.
• If lines are interrupted in the middle, be sure to connect them with connectors, making sure that the
cable insulation is not peeled off for more than 50 mm. In addition, always use shielded cable.
• Do not coil cables. If cables are long and are coiled, mutual induction and inductance will increase and
will cause malfunctions. Always use cables fully extended.
• When installing noise filters for Encoder Cables, use clamp filters. The following table shows the rec-
ommended clamp filter models.
Maker
NEC TOKIN EMI core
TDK Clamp filter
• Do not place the Encoder Cable in the same duct as Power Cables and Control Cables for brakes,
solenoids, clutches, and valves.
H Improving Control I/O Signal Noise Resistance
Positioning can be affected if control I/O signals are influenced by noise.
• Use completely separate power supplies for the control power supply (especially 24 V DC) and the
external operation power supply. In particular, be careful not to connect the two power supply ground
wires. Install a noise filter on the primary side of the control power supply.
• As much as possible, keep the power supply for pulse command and deviation counter reset input
lines separate from the control power supply. Be particularly careful not to connect the two power sup-
ply ground lines.
• It is recommended that a line driver be used for pulse command and deviation counter reset outputs.
• Always use twisted-pair shielded cable for pulse command and deviation counter reset signal lines,
and connect both ends of the shield to frame grounds.
• Always use twisted-pair shielded cable for speed and torque command signal lines, and connect both
ends of the shield to frame grounds.
• 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 Servo Driver input section or
the controller output section.
• For encoder output (phase-A, -B, and -Z) lines, be sure to use twisted-pair shielded cable, and con-
nect both ends of the shield to frame grounds.
• For open-collector specifications, keep the length of wires to within two meters.

3-2-5 Wiring for Conformity to EMC Directives

When the wiring conditions provided in this section are satisfied, the wiring will conform
to EMC Directives (EN55011 Class A Group 1 (EMI), EN61000-6-2 (EMS)). These
3-28
Name Model
ESD-SR-25
p
ZCAT2032-0930
ZCAT3035-1330
ZCAT2035-0930A
Chapter 3