6. SAFETY FUNCTIONS
Area which the tool cannot enter can be specified with stored stroke check
:Forbidden area for the tool
Fig.6.2 Stroke check
When the tool exceeds a stored stroke check, an alarm is displayed and
the tool is decelerated and stopped.
When the tool enters a forbidden area and an alarm is generated, the tool
can be moved in the reverse direction from which the tool came.
Parameters (Nos.1320, 1321) set boundary. Outside the area of the set
limits is a forbidden area. The machine tool builder usually sets this area
as the maximum stroke.
If the maximum rapid traverse rate is F (mm/min), the maximum overrun
amount, L (mm), of the stored stroke check is obtained from the following
L (mm) = F/7500
The tool enters the specified inhibited area by up to L (mm). Bit 7 (BFA)
of parameter No.1300 can be used to stop the tool when it reaches a point
L mm short of the specified area. In this case, the tool will not enter the
Bit 6 (LZR) of parameter No. 1300 can be used to select whether to enable
each stroke limit after a reference position return operation is performed
manually or with G28 after power–up or to enable each stroke limit
immediately after power–up.
After the power is turned on, if the reference position is in the forbidden
area of each limit, an alarm is generated immediately.
If the enters a forbidden area and an alarm is generated, the tool can be
moved only in the backward direction. To cancel the alarm, move the tool
backward until it is outside the forbidden area and reset the system. When
the alarm is canceled, the tool can be moved both backward and forward.
In setting a forbidden area, if the two points to be set are the
same, all areas are forbidden areas.
Stored stroke check
Overrun amount of
stored stroke check
Effective time for a
Releasing the alarms