
B–63833EN–1/02
2. PREPARATIONS FOR OPERATION
126
[Classification] Input signal
[Function] This signal is used to inhibit the machine from moving, and is effective
regardless of the selected mode.
[Operation] When the *IT signal is “0”, the axis movement is decelerated and stopped.
In automatic operation, blocks containing M, S, T or B 2nd auxiliary
mode commands are executed consecutively until a block containing an
axis move command is encountered; the system then stops and is placed
into the automatic operation mode (cycle start lamp signal STL is “1”,
feed hold lamp signal SPL is “0”). When the *IT signal turns to “1”,
operation resumes (Figs. 2.5(c), (d)).
*IT
Command read
Axis move
Fig. 2.5 (c) Block containing axis move commands only
(manual and automatic operation)
MF/SF/TF
FIN
*IT
Command read
Fig. 2.5 (d) Block containing auxiliary functions only
(automatic operation)
NOTE
The overtravel distance of the motor after turning *IT to “0”
is represented by the following formula.
Where
Q
max
: Overtravel quantity (mm or inch)
F
m
: Feedrate (mm/min or inch/min)
T
c
: Cutting time constant (ms)
T
s
: Servo time constant (Ts = 33ms normally)
A : Processing time of CNC
A = 50ms
Q
max
=F
m
@
1
60
× (
T
c
1000
+
T
s
1000
+
A
1000
)
All axes Interlock signal
*IT<G008#0>