
B–63503EN/02
9. CONNECTION TO FANUC I/O Link
140
NOTE
Xm+1.0 through Xm+1.7 are DI pins for which a common
voltage can be selected. That is, by connecting the COM1
CE54(A02) pin to the +24 V power supply, a DI signal can
be input with its logical state reversed. If, however, a cable
is connected to ground, it has the same effect as inputting
an ON state DI signal. To prevent this from occurring, the
connection of the COM1 CE54(A02) pin to the 0 V power
supply is recommended whereever possible.
For safety reasons, the emergency stop signal needs to be
allocated to an appropriate bit of the addresses for which
the common voltage is fixed, ranging from Xm+0.0 to
Xm+0.7. See “Address allocation” in Section 9.5.9 for
details of how to allocate the emergency stop signal.
For unused DI pins allocated to the addresses for which the
common voltage is fixed (from Xm+1.0 to Xm+1.7), the logic
is fixed to “0”. For unused pins allocated to Xm+1.0 to
Xm+1.7 for which the common voltage can be selected, the
logic is fixed to “0” when the COM1 CE54(A02) pin is
connected to the 0 V power supply. When the COM1
CE54(A02) pin is connected to the +24 V power supply, the
logic is fixed to “1”. The logic of the unused pins allocated
to Xm+1.0 to Xm+1.7 is variable when the contact of the
COM1 CE54(A02) pin is open.