6. CONNECTION OF I/O UNITS TO
(b)Output signal driver
Eight signals are output from each of the output signal driver
elements used on this operator’s panel connection unit.
The current of each output signal is monitored in the driver
element. When overcurrent is detected, output of that signal is
turned OFF. Once signal output is turned OFF due to overcurrent,
signal output is restored to ON as turning signal output OFF
eliminates the overcurrent state. For this reason, output is
repeatedly switched ON and OFF when the output signal falls to
ground or when it is in an overcurrent state. This also happens when
a large surge current load is connected.
The driver element also has an overheat detection circuit. When the
overcurrent state is continuous due to outputs having fallen to
ground and the temperature inside the element rises, output of all
eight signals is turned OFF and this OFF state is held. Output is
restored for each individual signal by temporarily setting output
logically OFF after the temperature inside the element has dropped.
Signal output can also be restored by powering OFF the system.
When the overheat detection circuit is activated on this printed
circuit board, the red LEDs mounted next to the driver element
light so that you can confirm activation of the overheat detection
circuit. (See Note.) When the overheat detection circuit is
activated, the CNC is notified of an alarm as a system alarm. (You
can also disable notification to the CNC system of this alarm by
closing (shorting) the short bar of setting pin CP1 mounted on this
printed circuit board. When notification is disabled, this alarm is
not treated as a system alarm.)
Correspondence between red LED and DO output signal
Red LED Name DO Output Signal Remarks
DAL1 Y q+0.0 to Y q+0.7
DAL2 Y q+1.0 to Y q+1.7
DAL3 Y q+2.0 to Y q+2.7
DAL4 Y q+3.0 to Y q+3.7
DAL5 Y q+4.0 to Y q+4.7
DAL6 Y q+5.0 to Y q+5.7
DAL7 Y q+6.0 to Y q+6.7
DAL8 Y q+7.0 to Y q+7.7
Lighting of the red LEDs and transfer alarm to CNC function
are supported on printed circuit board 03B onwards.