
B–62073E/04
6. CONNECTION OF I/O UNITS TO
MACHINE INTERFACE
153
The output signals from the connection unit are used for driving relays and
light emitting diodes for indication on the machine. A semiconductor
contact is used as a driver. The output type is direct current output signal
A.
(1)Direct current output signal A
(a) Driver ratings
(i) Maximum load current when the output is on: 250 mA or less
including an instantaneous value
(ii)Maximum voltage drop when the output is on: 6I
L
(volts),
where I
L
is the load current
(Example) When I
L
= 250 mA, 6 × 0.25 = 1.5 (V)
(iii)Withstand voltage when the output is off: 50 V or less including
an instantaneous value
(iv)Leakage current when the output is off: 100 mA or less
Relay
Machine
Regulated power
supply on the
machine
CNC
Semicon-
ductor
contact
(b)When an inductive load such as a relay is connected to the machine,
mount a spark killer as near the load as possible (20 cm or less).
When a capacitive load is connected to the machine, insert a serial
resistor to limit the current so that the rated current and voltage are
ensured even for an instantaneous value.
(c) When the lamp is turned on directly by the solid–state relay output,
a surge current may flow and damage the driver. Add a protective
circuit shown below so that the rated current and voltage are
ensured even for an instantaneous value.
+
Lamp
Regulated power
supply
CNC
Semicon-
ductor
Protective resistor
6.4.3
Output Signal
Regulations for the
Connection Unit