
Dra
Title
SheetDescri
tionDesi
n Date Edit
FANUC Pulse Input Type
Digital Servo Adapter
Connection Manual (Hardware)
A-77226EN
/ 6
2.3 ACTION AGAINST NOISE
The PDSA has been steadily reduced in size using surface-mount
and custom LSI technologies for electronic components. The PDSA
also is designed to be protected from external noise. However, it is
difficult to measure the level and frequency of noise quantitatively,
and noise has many uncertain factors. It is important to prevent
both noise from being generated and generated noise from being
introduced into the PDSA. This precaution improves the stability of
the machine system.
The PDSA component units are often installed close to the parts
generating noise in the power magnetics cabinet. Possible noise
sources into the PDSA are capacitive coupling, electromagnetic
induction, and ground loops.
When designing the power magnetics cabinet, guard against noise
in the machine as described in the following section.
2.3.1 Separating Signal Lines
The cables used for the machine are classified as listed in the following
table:
Process the cables in each group as described in the action column.
Group Signal line Action
Primary AC power line
Secondary AC power line
AC/DC power lines
(containing the power lines for the
servo and spindle motors)
AC/DC solenoid
A
AC/DC relay
Bind the cables in group A
separately (Note 1) from groups B
and C, or cover
group A with an electromagnetic
shield (Note 2).
See Section 2.4.2 and connect
spark killers or diodes with the
solenoid and
relay.
DC solenoid (24VDC)
DC relay (24VDC)
DC power line
DI/DO cable between the I/O Unit and
power magnetic cabinet
B
DI/DO cable between the I/O Unit and
machine
Connect diodes with DC solenoid
and relay.
Bind the cables in group B
separately from group A, or cover
group B with an electromagnetic
shield.
Separate group B as far from
Group C as possible.
It is more desirable to cover group
B with the shield.
Cable for pulse command and
feedback.
Cable for analog output.
RS-232-C and RS-422 interface cable
Cable for the battery
C
Other cables to be covered with the
shield
Bind the cables in group C
separately from group A, or cover
group C with an electromagnetic
shield.
Separate group C as far from
Group B as possible.
Be sure to perform shield
processing in Section 2.4.3.