48
(3) Cables
Use shielded cables for the cables which are connected to the I/O
modules and may be extended out of the control panel.
If a shielded cable is not used or not grounded correctly, the noise
immunity will not meet the specified value.
(a) Grounding a shielded cable
• Ground the shield of the shielded cable as close to the
module as possible so that the grounded cable will not be
affected by electromagnetic induction from ungrounded
cables.
• Ground the exposed shield section to large area on the
control panel. A clamp fitting can be used as shown in
below. In this case, mask off inner wall surface of the control
panel, which comes in contact with the clamp.
POINT
Grounding with a vinyl-coated wire soldered onto the shielded section of the shielded cable
as shown below is not recommended. Doing so will raise the high-frequency impedance,
resulting in loss of the shielding effect.
Screw
Clamp fitting
Shielded cable
Paint mask
Shielded cable
Wire
Solderless terminal
Summary of Contents for 13J240
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