6. CONNECTION OF I/O UNITS TO
A power supply which satisfies the above specifications
shall be connected to the DOCOM and 0V power supply
terminals for the output signals. The maximum current that
can be carried by the DOCOM pin is 2.0 A. The total load
current must not exceed this value, therefore.
The output signal driver used with the operator’s panel connection unit
can output up to eight signals.
The driver element monitors the current of each output signal. If an
overcurrent is detected, the output of that signal is turned off. Once a
signal has been turned off, the overcurrent will no longer exist, such that
the driver turns the signal on again. Therefore, in the case of a ground fault
or overload, the output of a signal will be repeatedly turned on and off.
This also occurs when a load which causes a high surge current is
The driver element contains an overheat detector, which turns off all eight
output signals if the temperature in the device exceeds the set value as a
result of an overcurrent caused by a ground fault or some other failure.
This off state is held. To restore signal output, logically turn the output
off then back on again, for each signal, after the temperature falls below
the set value. Signal output can also be restored by turning the system
power off then back on again.
On the PCB, a red LED beside the driver element lights once the overheat
detection circuit operates.
The overheat detection circuit also causes a system alarm
to be issued to the CNC. (When setting pins CP1 on the
PCB are closed (jumpered), this alarm is not issued to the
Red LED name DO signals 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
Output signal driver
between red LEDs and