
B-63943EN/02 8.CONNECTION TO FANUC I/O Link
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8.6.9 Other Notes
DO signal reaction to a system alarm
If a system alarm occurs in a CNC using this 48/32-point I/O module,
or if I/O Link communication between the CNC and operator's panel
I/O module fails, all the DO signals of the I/O module are turned off.
Therefore, due care must be taken when setting up the machine
sequence. Also, the same phenomenon occurs if the power of the
CNC or the I/O module is turned off.
Address allocation
For the operator's panel I/O module, I/O addresses are mapped as
follows.
Input signal
Xm
Xm+1
Xm+2
Xm+3
Xm+4
Xm+5
Xm+6
Xm+7
Xm+8
Not used
Xm+9
Xm+10
Xm+11
MPG
Xm+12 (for 1st MPG)
Xm+13 (for 2nd MPG)
Xm+14 (for 3rd MPG)
DO alarm detection
Xm+15 (DO alarm
detection)
DI space map
Output
signal
Yn
Yn+1
Yn+2
Yn+3
DO space map
Basically, this 48/32-point I/O module is allocated a group of DI
addresses (16 bytes) and a group of DO addresses (4 bytes). This
address allocation is explained below.
The MPG interface (MPG counter) occupies DI space from Xm+12
through Xm+14. These addresses are fixed, and Xm+12 through
Xm+14 must be allocated as a DI work area to enable the use of the
MPG. Therefore, when using an MPG for the i series CNC, allocate
DI addresses in units of 16 bytes. Do not use the DI space from
Xm+12 through Xm+14 for Ladder; the CNC processes the MPG
counter value directly.
DI address Xm+15 is used for detecting overcurrent and overheating
alarms that occur in the IC used in the DO driver. [For details, see
the section describing the detection of DO (output signal) alarms.]
This address is fixed, and must be allocated as a work area before it
can be used. When using this area, therefore, allocate DI addresses
in units of 16 bytes.
Basically, I/O addresses can be allocated to the 48/32-point I/O
module freely. When allocating DI addresses, however, consider