Instruction manual
12.
OPTIONS AND
AUXILIARY
EQUIPMENT
12.2.3 Relays
The following relays should be used with the interfaces:
Interface
Selection
Example
Relay used especially for switching on-off input
(twin contacts).
command (interface
DI-1)
signals
To
prevent defective contacts, use a relay for small slgnal
(Ex.)
OMRON
:
type
G2A,
MTi
Relay used for digital output signals (interface
DO-1)
Small relay with
12\rDC
or
24VDC
of 40mA or
less
12.2.4 Noise reduction techniques
Noises are classfled into external noises whch enter the servo amplifier to cause
it
to malfunction and
those radiated by the servo amphfier
to
cause peripheral devices
to
malfunction. Since the servo amplifier
is an electronic device whch handles small
signals,
the following general noise reduction techmques are
required.
Also,
the servo amphfier can be a source of noise
as
its
outputs are chopped
by
hgh carrier frequencies. If
peripheral devices malfunction due
to
noises produced by the servo amphfier, noise suppression measures
must be taken. The measures wlll
vary
slightly with the routes
of
noise transmission.
(1) Noise reduction techniques
(a) General reduction techmques
*
Avoid laying power lines (input and output cables) and signal cables side by side
or
do not bundle
them together. Separate power lines from signal cables.
*
Use shelded, twisted pair cables for connection with the encoder and
for
control signal
transmission, and connect the slueld to the
SD
terminal.
3
Ground the servo ampuer, servo motor, etc. together
at
one point (refer
to
Section 3.9).
(b)
Reduction techniques for external noises that cause the servo amphfier
to
malfunction
If there are noise sources (such as
a
magnetic contractor, an electromagnetic brake, and many
relays which make a large amount of noise) near the servo amphfier and the servo amphfier may
malfunction. the following countermeasures are required.
*
Provide surge absorbers on the noise sources to suppress noises.
*
Attach data line
filters
to the signal cables.
. Ground the shields of the encoder connecting cable and the control signal cables with cable clamp
fittings.
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